Ketones. A new superfuel?

Previous Cyclist or Scientist articles have addressed the three main macronutrients involved in exercise metabolism: carbohydrates, fats and proteins. But there is a fourth fuel source, ketones, which have become very fashionable in the cycling media and generated some heated comment sections on articles citing their use in the Tour de France peloton.

acetone
Acetone. Image Credit: Pixabay

What are Ketones?

Ketone bodies are produced naturally in the liver in conditions of reduced carbohydrate availability and serve as an alternative fuel source for the brain, heart and skeletal muscle. They are primarily generated from free fatty acids in adipose tissue. The smallest and simplest of these ketones is one you may have already heard of and used before, acetone. So how could a key solvent in nail polish remover be used as a performance enhancer for endurance athletes?

There have been many studies investigating the effects of ketone metabolism on exercise performance through prolonged fasting and ketogenic diets. Any benefits of the natural state of ketosis haven’t been all that useful in professional cycling given racing on rashers of bacon or back to back days without eating aren’t very performance enhancing… Recently however, exogenous ketone esters (ones that you can eat) have been investigated in the laboratory and have made their way into the back pockets of riders in the pro peloton.

TDF-Stage2-0005
Jumbo Visma have openly used ketone esters during the 2019 Tour de France. Image Credit: teamjumbovisma.com

How are they consumed?

Rather than rely on the body to create its own ketone bodies, two different forms of ketones can be ingested to allow almost immediate intake into the muscle for use as fuel. Ketone salts were investigated first, though any dose of these large enough to provide useful fuel for exercise had athletes going to the toilet faster than they were getting to the finish line.

Ketone esters are far more tolerable for the gut in substantial doses and provide an acute method of elevating blood levels of beta-hydroxybutyrate (βHB), the ketone body used as fuel within the muscles. Researchers have found the ideal dosage to maximise the benefits, while minimising trips to the bathroom, is around 600mg per kg body mass. 40g for a 67kg rider is relatively easy to mix into a sports drink although all reports are that the taste is less than favourable… This dosage, just 10 minutes after ingestion, elevates blood βHB concentration to the equivalent of a 72 hour fast, and after 30 min, increases concentration to that achieved on a ketogenic diet.  Ketosis and carbs, the best of both worlds.

This βHB is then taken into muscle fibres via the MCT1 receptor. This is significant because this is expressed predominantly in type 1 (slow twitch) muscle fibres. It’s therefore likely ketones are used predominantly during endurance exercise or sections of a race where the intensity is lower.

TJP-595-2857-g002
Image credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5407977/

How do they work?

Ketones are suggested to provide a thermodynamic advantage over fats and carbohydrates as a fuel source because the available free energy to perform work is greater. Less oxygen is required per mole of carbon to oxidise. Basically, you get more for less, in theory…

This theoretic benefit has been supported by recent studies on performance when using exogenous ketone supplementation. Cycling performance in a 30 min time trial was increased by 2% when subjects were given ketones and carbohydrates rather than just an optimal level of carbohydrate alone. Another benefit for road cyclists is the carbohydrate-sparing effect of using ketones as a fuel source. Ketones have been shown to provide up to 18% of aerobic energy production during endurance exercise. This would allow those carbs to be saved for later in a race when the high intensity is necessary.

Benefits are suggested to be heightened in trained individuals who have a greater ability to take up and oxidise ketones within the muscle due to the countless hours of aerobic training undertaken. So, if you’re lucky to squeeze in one or two rides a week you might not see the same benefit from chugging down a bottle of ketones as the pros do.

light-bulb-3104355_1280
Ketones could provide more for less in comparison to other fuel sources. Image credit: Pixabay

 

What else can ketones do?

There’s also some promising research on the use of ketones in aiding recovery. Ingestion of ketones after exercise again could allow the body to save up on carbohydrates as well as protein during this period. This would mean faster replenishing of muscle glycogen stores (up to a 50% increase) before the next race or training session as well as increased protein synthesis and decreased muscle breakdown. Athletes could then experience the benefits of fasted training sessions without the associated increased muscle breakdown. There are limited studies on this, but the work done so far is another box ticked for exogenous ketones.

Of course, you couldn’t have an article about ketones or ketosis without mentioning weight loss. Studies have also suggested that the suppression of appetite after the ingestion of ketone esters could also be helpful in decreasing body fat.

TJP-595-2857-g004
Image credit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5407977/

What to watch out for

A lot of the above research may read as an advertisement encouraging you to go out and fill your pantry with ketone esters (an expensive prospect at up to AU$50 per serving…). It’s important, however, to note that many of the experiments are on small sample sizes (10 or less) and few repetition studies have been conducted to date. For example, it is yet to be determined whether the carbohydrate-sparing effect of ketones isn’t simply due to decreasing the rate of aerobic glycolysis. If this were the case, it would mean a higher reliance on anaerobic energy production, quite a painful phenomenon if required too often in a bike race…

So far, only the short-term effects of ketone ester ingestion have been tested; we’re yet to see what long-term physiological changes could occur with chronic ketone ingestion.

If you are keen to give them a go, its important to be aware of your dosage. In this case, more is not merrier… 20% of participants in one study reported flatulence, nausea, diarrhoea and dizziness when taking just the recommended dose (~600mg/kg body mass) – this increased to almost 100% of participants when the dosage was doubled. Definitely give them a trial run in training before smashing them down in a race…

dumpulin
Could the infamous Dumoulin dump during the 2017 Giro be due to an early trial of ketone supplementation??? Image credit: flobikes.com

 

The take homes

  • Ketones are a fourth fuel source for exercise along with carbohydrates, fats and proteins.
  • They are produced in the body during fasting or a ketogenic diet but can be ingested easily in the form of a ketone ester.
  • Research suggests they may be beneficial in endurance exercise through efficient energy production (low oxygen cost) and a carbohydrate sparing effect.
  • They could aid recovery through increasing glycogen replenishment and protein synthesis.
  • Overdoses can make for a very unhappy gut.
  • The studies published so far are very supportive of their ability to provide a performance benefit to athletes but there’s still further research to be done.

 

This was a heavily requested topic and good reason to get back into the research after a lengthy lay-off due to a stolen laptop and heavy racing period. As with most expensive supplements, I secretly hoped the hype around ketones was being overdone and that the research would suggest they’re not worth the coin. Unfortunately it looks like those able to fork out the $ for this product may be getting a genuine advantage on the competition. I’m currently 7 stages into the Tour of Qinghai Lake in the middle of China where I don’t see myself finding a supply of ketone esters anytime soon. Hopefully we can pull off some big results in this second week and maybe the prize purse might allow me to give the ketones a go for myself later in the season… Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Cheers,

Cyrus

Request a Topic

Want to know the results of research on a particular topic of interest? Any questions about a supplement, food or intervention you’ve heard is the next big thing? Leave a question or a topic suggestion in the comments and I’ll sift through the papers for you.

A$10.00

Support the site

This blog requires a considerable money and time investment to startup and maintain so any support is greatly appreciated. Help keep this content available for all users!

A$10.00

Advertisements

Pain and Performance, Friend or Foe?

In the box, the hurt locker, the pain cave. Every athlete has ventured to these places countless times to get the most out of themselves during competition, but how much faster can one go by simply saying “shut up legs”, and are there ways get around the suffering?

shut up legs
Image Credit: elliebeanprints.co.uk

We’ve all experienced the burning sensation associated with sprinting to the top of a hill, the back half of a long TT or trying to complete a singular chin-up (cyclists take a good hard look at yourself). The reasoning behind these highly unpleasant sensations is physiologically important for protecting the working muscles as well as the heart.

Every muscle contraction causes minute damage to the cell membranes within the muscle (scary right?), and the more forceful each contraction the more damage occurs (visit the blog on antioxidants for why this is surprisingly useful when it comes to training). This damage to the cells release cyclooxygenase enzymes (you may have heard them referred to as COX) which essentially lead to the brain being told “ow, stop going so hard” and generating that awful sensation we’ve all felt (there’s a few extra steps in this process which you can look into here).

As it happens during a race, athletes don’t tend to be too interested in preventing muscle damage and would much rather go faster, win the race and then worry about the rest later. For this reason, managing pain, whether through fighting it or embracing it, can be a vital skill for competitors to gain an edge over their opponents. Just the act of regular high-intensity training has been proposed to alter pain perception and tolerance. Elite athletes have also been found to have a higher pain-tolerance than non-athletes but a fair chunk of that effect size may stem from those athletes being required to be naturally capable of handling pain just to get to the top of their sport.

back-pain-feature.jpg
Image Credit: cyclingtips.com

Unfortunately, pain during exercise is a notoriously difficult area to research since pain is subjective. It’s a tough task for researchers to distinguish whether one athlete is hurting more than another, regardless of how epic one’s pain face may be. Two current areas of research have looked at ways to combat pain by either psychological or pharmaceutical means.

The power of the mind

Psychological methods include the athletes either attempting to ignore or embrace the pain. Ignoring the pain, AKA the ‘shut up legs’ approach, usually comes from mental distractions such as focusing on aspects outside the competition (crowd/scenery/etc.) or through mental imagery and positive self-talk (picturing the glory of crossing the finish line first or going to your ‘happy place’).

Embracing the pain, AKA the ‘pain is temporary’ approach, is an almost meditative process which involves accepting that the body is telling you to stop but forcing yourself to keep pushing as the pain of losing for many is greater than the pain of suffering during an event. Unfortunately, the research is still on the fence as to whether these techniques actually provide a significant performance benefit in endurance events.

Another psychological method to manage pain is called ‘end-point manipulation’. In this technique athletes tell themselves to “just make it to the next corner” or “just one more lap” repetitively to squeeze the most out of themselves. Interestingly, studies have found this can work up until a certain point. For example, athletes could be told the finish line was 500m further than they initially thought and could still maintain the same output for the extra distance. However, when the finish line was, say, 1 or 2km further than expected, athletes would ‘crack’ and output would drop significantly.

Martin_Tony_Algarve12_st6-1
Image Credit: Tim de Waele via velonation

The Uncle Dougs

Given the range of painkillers now readily available to the public it’s no surprise that some athletes will also use pharmaceutical means to directly block out the pain. There’s no doubt these are effective in preventing the pain caused by intense physical activity but there’s also some health and performance side-effects of which everyone should be aware.

The common over-the counter painkillers (aspirin, paracetamol, etc.) usually act on the COX enzymes mentioned above. Inhibiting action of this enzyme means that the muscle damage caused during exercise causes significantly less pain for the athlete. This can be acutely beneficial for performance however can cause issues later as a result of the body damaging itself more than under normal circumstances. The fatigue and damage to the muscle fibres most effective for the contractions required can result in recruitment of less effective fibre groups, or just simply damage the muscle to the point where it can no longer contract as forcefully. In short events this may not be a problem but at the end of a long one-day race or in a multi-stage tour the use of painkillers can be more detrimental than beneficial.

The anti-inflammatory effect of many of these pain medications prevents the effective repair and strengthening of muscles post exercise, as discussed in this post. More worryingly, COX inhibitors have been associated with an increased risk of myocardial infarction and stroke. In a situation where the cardio-vascular system is already under serious stress (e.g. intense exercise) this is a risk you may want to think twice about before popping those panadols!

sms13275-fig-0002-m
Image Credit: www.ncbi.nlm.nih.gov/pubmed/30102811

The elephant in the room when it comes to pain in sport, particularly professional cycling, is recently banned tramadol. Tramadol is an opioid medication, the same family as morphine but with around one tenth of the potency. It acts by preventing the reuptake of serotonin, meaning there’s more serotonin that hangs around in the system resulting in a reduced sensitivity to pain. As many will know, opioids do have a number of nasty side effects. Nausea, itchiness and lack of perception of necessary stimuli such as hunger and thirst can provide problems directly on the bike. The highly addictive properties of these medications can result in dependence on these painkillers and cause severe withdrawals or chronic pain when users stop taking them. Knowing this, it’s a surprise the WADA tram ban didn’t come earlier!

Take home messages:

  • Pain is a protective mechanism to prevent damage
  • Elite athletes have a higher pain tolerance than the general population, indicating pain management can benefit performance
  • Psychological methods can be used to manage pain during exercise, though research indicates the benefits to performance are limited
  • Over the counter pain medication can be effective in the short term but may be detrimental in longer events and can increase risk of cardiovascular complications
  • Tramadol and other opioids are very effective at decreasing pain sensitivity but can have serious short and long-term side effects
  • Research provides no clear message as to how athletes can use analgesic drugs while minimising unwanted side effects

Pain is a part of high-intensity exercise whether we like it or not. The mental strength involved in coping with this is often what sets the best apart from the rest. You can be as strong as you want in the legs but often its what’s between the ears that counts. 

IMG_5706
2018 Aus U23 TT Champs. Ventured to some dark places fighting against the pain on the run home here. The pain was intensified when I found I’d finished just 2 seconds off the podium and 15 seconds off the win. Stiff bikkies

 

 

This piece was written during some big travel days involved in getting 50kg of belongings (mostly sunscreen) from Melbourne to Girona. I’ll be based here for the majority of this season and I’m looking forward to some big days on the local climbs to get ready for my first Euro race of the season, Circuit des Ardennes, in two weeks. I’ll certainly be staying clear of the painkillers and from all reports the domestic racing scene in France is brutal so I’m sure to be in for a painful few days. Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Cheers,

Cyrus

Request a Topic

Want to know the results of research on a particular topic of interest? Any questions about a supplement, food or intervention you’ve heard is the next big thing? Leave a question or a topic suggestion in the comments and I’ll sift through the papers for you.

A$10.00

Support the site

This blog requires a considerable money and time investment to startup and maintain so any support is greatly appreciated. Help keep this content available for all users!

A$10.00

Coaching Enquiries

Intra-Session Protein for Performance; Yeah or Nah?

Cycling requires repetitive contractions of big muscle groups for hours on hours, so why isn’t anyone reaching for a protein shake mid-ride?

water-830374_1280.jpg
Image credit: 926663 via Pixabay

In my time working in gyms I’ve seen some a common occurrence amongst lifters – If someone’s hitting the gym for longer than an hour, a protein shake will likely be in hand between sets. Cycling can have ridiculous demands on the body and it raises the question of whether cyclists should be the ones with a protein shake mid-ride? Not only can cycling be taxing to the body, but, protein itself plays some interesting roles which suggest it could have a positive impact on performance.

  • Protein is a macronutrient (alongside carbohydrates, fats and alcohol).
  • protein can be converted to glucose (the form of carbs the body prefers).
  • protein will be oxidized (burnt) in endurance exercise.

Given these facts, it begs the question of whether mid-ride protein supps would have a positive effect on performance.

To be specific we are asking “what are the effects of intra-session protein supplementation on acute endurance cycling performance outcomes”. We aren’t looking at whether protein makes you recover for the next session or whether protein makes you feel less sore after a ride, etc etc. A bunch of that stuff we might tackle in the coming weeks.

Interestingly, there isn’t a great deal of data on endurance performance and intra-session protein supplementation. Don’t get me wrong searching for “effects of protein on endurance performance” will return heaps, but none of these results look at exactly what we are after.

There is so little out there that I couldn’t find a single paper that compared protein alone to placebo, carbs or carbs+protein. Not a single paper. Confirming my lack of results, a 2014 systematic review didn’t find a single paper on our topic. (Effects of Protein Supplements on Muscle Damage, Soreness and Recovery of Muscle Function and Physical Performance: A Systematic Review YEAR). The lack of research isn’t that surprising. The pathways of energy production in skeletal muscle are well known and, as we’ve seen, carbs are king. Researchers aren’t as likely to look at protein alone as carbs have such a well-documented effect on performance.

laboratory-2815641_1280.jpg
Image credit: jarmoluk via Pixabay

And with this we have an answer to our original question:

Q: “if I want to go faster in a long training ride or a long race should I swap out my carbohydrate sports drink for a protein supplement?”

A: “Probs not, stick with the carbs”

Or you could say “at this stage, it appears that intra-session protein supplementation alone is extremely unlikely to cause any significant improvement in performance. With that said, there are few if any good studies that directly compare protein to other supplements so there is a small chance that it does have a positive performance effect but, as of yet, it is unlikely.”

I did find another question which is relevant.

“What is the effect of intra-session supplementation of carbs AND protein on performance?”

This one has more research. Rather than go through all the papers I found, here is a nifty figure from a review on the topic which we’ll breakdown to look at some of the nuances of this topic. (Is There a Need for Protein Ingestion During Exercise? 2014)

figure 1 cal
Studies investigating improvement in performance with intra-session carbohydrate + protein supplementation compared with carbohydrate alone. White bars are studies that use Time To Exhaustion (TTE), black bars are studies that used Time Trial (TT) as a performance metric. Credit: Is There a Need for Protein Ingestion During Exercise? 2014

At first glance it looks like carbs + protein is amazing for performance! But, there is more than meets the eye. Before we break it down, lets chat carbs quickly. The body is great at getting carbs from your gob into your muscles (suss out the last blog for more on this). On average about 60gms of carbs can be ingested and used per hour, so an optimal carb supplement should provide about 60gms of carbs per hour.

In the trials from the graph, they all used a similar format: a cyclist would ride a TTE (time to exhaustion) or TT test. Once with a carb drink (C) and then another time a few days later with carbs + protein (C+P) and the researchers would compare the times from the (C) to the (C+P).

With our knowledge of optimal carb supps lets break the trials down into 2 groups

  • “Optimal” Trials that used 60gms of carbs per hour in both (C) and (C+P). (trials from the above graph that had optimal carb supps were: Breen et al (2010), Osterberg et al (2008), Sanders et al (2009), Valentine et al (2008), Van Essen and Gibala (2006)
  • “Sub-optimal” Trials that used less than 60gms of carbs per hour in both (C) and (C+P). (trials which had sub-optimal carb supplementation were: Ivy-et al (2003), Lee et al (2003), Martinez-Lagunas et al (2010), Romano-Ely et al (2006), Saunders et al (2004), Saunders (2007)

When I replot the graph without the “sub-optimal” trials(<60gms of carbs per hour) the graph tells a different story

figure 2 cal
First graph with studies using sub-optimal carb delivery rates taken out. Credit Is There a Need for Protein Ingestion During Exercise* I couldn’t work out carbs per hr for Madsen (1996) and G Van Hall et al (1995) so we’ll give them the benefit of the doubt and leave them in.

Crazy how much this changes the picture! The effect size goes from quite large to either very small or non-existent. It’s pretty clear that when there are enough carbs delivered (>=60grams  per hour) adding protein doesn’t improve performance.

This makes sense when you think about it, carbs (and fats) are the fuel/s for endurance work. The body is great at burning them, great at storing them and great at delivering them from the gut and liver to the muscle to keep the body moving. So when the fuel tanks get low and you’re filling it up with fuel via a carb + protein drink the body will be mostly using the carbs, assuming there are enough carbs provided by the supplement. We see the theory work out in practice here: when a trial compares an optimal carb supp (C) to an optimal carb supp plus protein (C+P), there is little difference in performance.

fuel-1596622_1280.jpg
Image credit: IADE-Michoko via Pixabay

For something of more scientific merit than the homemade graph from above,  a systematic review on the topic concluded:

“it was also evident that when carbohydrate supplementation is delivered at or above 60 g·h−1, protein supplements provide no further ergogenic effect, regardless of the performance metric used”

Still, we saw that some of the “sub-optimal” trials had a performance improvement in the (C+P) group compared to the (C) group. The thing to remember is that in these “sub-optimal” trials the (C) and (C+P) were getting less than 60gms of carbs per hour, but the (C+P) group is getting extra calories from the protein and these extra calories might be helping fuel performance. Some of these trials delivered less total calories than an optimal carb supp would, this means that sub-optimal carbs intake + some protein may help performance more than just a sub-optimal carb supp. So you might get a small performance benefit from adding in protein if you’re short on carbs and there’s nothing else available.

Take home messages:

  • there isn’t much data on whether intra-session protein (alone) supplementation is good for performance, but, it is unlikely to help.
  • If you’re consuming less than 60gms of carbs per hour (ie trying to reduce caloric intake) adding protein may help you perform better
  • If you’re consuming the optimal level of equal to or more than 60gms of carbs per hour on a ride adding protein won’t help you go faster.

So intra-session protein for cycling performance?

The research says nah. Getting your 60gms of carbs in per hour is your best bet.

sugar-3982977_1280
Image credit: maxmann via Pixabay

Callum Baker

PhD Candidate | Accredited Exercise Physiologist | Clinical Teaching Fellow
The University of Sydney

 

A huge thanks goes to Callum for producing this article for Cyclist or Scientist. Great to have a PhD Candidate writing for the website in an area of expertise and I hope you gained a few handy pointers from the article. As for myself, I’m in Australia for another few weeks of training in the sunshine before heading over to Europe to get stuck into some racing with EvoPro. Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Cheers,

Cyrus

Request a Topic

Want to know the results of research on a particular topic of interest? Any questions about a supplement, food or intervention you’ve heard is the next big thing? Leave a question or a topic suggestion in the comments and I’ll sift through the papers for you.

A$10.00

Fuelling the engine. Competition carbohydrate consumption

Is doesn’t take a biochemist to know that carbohydrates are the MVP when it comes to fuelling high intensity exercise. But how much do we really need, and how do we know we’re putting in the right stuff?

bread-3491885_1280.jpg
Image credit: MabelaAmber via Pixabay

Our body has three main fuels to produce the energy required for the thousands of muscle contractions during an endurance sporting event. Carbohydrates are used predominantly when the pace is on, fats when the intensity is lower and once the carbs are gone and there’s less fat available the body will start burning muscle protein as a last resort.

In a high intensity event such as a bike race, where bursts of power could be required at any moment, readily available blood glucose is essential throughout a race to maximise performance. Endurance training prior to an event increases the mitochondria content in adipose tissue, essentially allowing greater energy production from fat sources over carbs. However, despite this being convenient for shedding some kg’s, fat oxidation is a much slower producer of energy than carbohydrate oxidation. Trying to race well off purely fat stores would be the equivalent of running a formula 1 car on diesel, the mileage may be better, but you’d be left behind easier than a phone charger in a hotel room.

ferrari-490617_1280.jpg
Image credit: urv via Pixabay

We’ve established that we need carbs to go fast, but how many for a long race?

Quick answer: a lot.

Long answer: Carbohydrates ingested during a race aren’t the only ones that go into turning the pedals around, with glycogen stores in the muscles and liver playing an essential support role however one that will be addressed in a post in depth at a later date… To get an idea of how much to put in, first we need to calculate how much is going out (physicists get excited).

Say in a hard race a cyclist averages 292 watts (you’ll see why this number shortly…). The average power output on a bike is simply the total energy put into the pedals divided by the time taken to do it. In order to work backwards and find the energy spent the average watts are multiplied by the total seconds. So cycling at 292 watts for an hour (3600 seconds) requires 1,051,200 joules of energy (1051kJ more commonly). Unfortunately, our bodies aren’t 100% efficient, and only around a quarter of the energy spent by the body ends up making it into the pedals, with most lost as heat. This means that 1051kJ of energy into the pedals each hour requires about 4200kJ. Because we still haven’t made it to the metric system for measuring the energy in food that equates to a whopping 1000Cal per hour. A seven-hour race like the Melbourne to Warrnambool would therefore require more than twice the recommended daily calorie intake during the race to put in the same amount of energy that’s put out.

IMG_0245.JPG
GP John Hannes Cup. A belgian Kermesse. I missed a few splits and spent a lot of time between groups this day averaging 294 Watts for 3h40min and burning close to 4000 calories

In terms of carbohydrates that 1000Cal per hour equates to around 250g of carbohydrate or 10 bananas. Before you go packing 70 bananas in your pocket it’s important to remember that carbohydrate isn’t the only fuel source during a bike race. A race with someone achieving a normalised power around 80% of their threshold will result in carbohydrates and fats providing close to an even share of the fuel supply. In the example above that would still require around 125g of carbs per hour, fortunately glycogen stores exist.

7866b65cf9398ea4690f1728a7a512ff.jpg
Image credit: durianrider

The task of putting in the same amount as you put out is made even harder by the fact that most people can only metabolise between 30-60g of carbohydrates per hour. Trained endurance athletes have been shown to reach 90g/h of carbohydrate metabolism but unfortunately this can’t be achieved as simply as shovelling down three or four muesli bars each hour.

To maximise absorption of carbohydrates in the gut it’s important to pay attention to which specific carbohydrates are put in. As one might expect, sugars are going to make their way into the bloodstream faster than complex carbohydrates, but there’s a few other tricks that can be used to max that carb absorption. Sugars make their way across the gut wall via a range of different specific transporters. The transporters can be thought of as gates that only let through their favourite sugars. If a mountain of glucose is poured into the system there’s only a certain few that can get through the gates into the blood at any time. But if some extra fructose is added then these have some unused gates to waltz through and get into the bloodstream, increasing the total carbohydrate absorption. (Before the biochemists send in the hate mail, it’s not quite this simple, with a bit more competition and a few more steps in the process but the principle is the same.)

cattle-720044__340.jpg
Glucose molecules waiting to get through the gut wall. Image credit: skeeze via Pixabay

Studies have found that for maximum absorption a ratio of 0.7:1 of fructose to glucose is best. Rather than weighing up the ratios of apples to jelly beans during a race this is usually achieved with a pre-made drink mix. Increasing the absorption rate of carbohydrates in the gut by nailing these ratios doesn’t just help keep the blood-glucose at optimal levels but also allows for better fluid absorption and causes the gut to empty faster, preventing the bloating or discomfort riders often face when trying to stuff their faces with carbs mid-race.

 

With all this in mind, eating during a race can seem a lot harder than trying to rip the top off a gel without ending up with half of it on your top tube. Fortunately, our bodies are pretty good at keeping us going, particularly with training, and there are many other adaptions that help give those muscles their sugar hit when chasing those last few attacks. Well-planned carbohydrate loading and training the body to prioritise fat burning where possible allow endurance athletes to always have that little extra ready to go when they need it however good fuelling during the race is always important.

For races where you really want to be firing at the end (most I hope) try to get in around 60-90g per hour at a ratio of 0.7:1 fructose to glucose and you’re on the right track. Most importantly, work out what works best for you. It’s not always possible to smash 4 gels an hour and most people just prefer solid food so give a few different combos a try during some long training days and settle on a nutrition plan you can back in to have you feeling good and going fast.

IMG_5721.JPG
National U23 Aus Champs 2018. I knew the race would only take around 2 hours and being well fuelled pre-race I did the race with one gel and some mineral water.

This topic had a lot to fit in, (fitting given the content) and ate into my Warrnie prep more than expected. Having loaded up on carbs the last few days and after a lot of fasted training to promote fat oxidation I’m confident I’ll be able to keep the blood sugar up throughout the race tomorrow. I won’t quite be aiming for the 90g/h mark on carb intake and given I’m racing solo with no team support I’ll be making do with whatever I can find out on the road in terms of bidons. Buying some fancy gels and drink mix would exceed my yearly salary of $0 so it will be a good chance to burn through all the leftover gels I’ve somehow accumulated over the past 12 months of racing. Hopefully they’ve got the sugar ratios I’m after and I can come home with some chocolates. Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Cheers,

Cyrus

Request a Topic

Want to know the results of research on a particular topic of interest? Any questions about a supplement, food or intervention you’ve heard is the next big thing? Leave a question or a topic suggestion in the comments and I’ll sift through the papers for you.

A$10.00

Overtraining and the Immune System. How Much is Too Much?

Overdoing it, burning the candle at both ends, cooking the goose. Athletes are notoriously bad for knowing when to back off and take a break, but why is it that going just a little too hard on the training track can lead to illness that can destroy an athlete’s whole season?

burnout-2158532__340
Image Credit: Geraldt via Pixabay

It’s no secret that athletes need hours upon hours of training to improve or maintain their level of performance. There are three markers generally used to assess the total load on an athlete during training and competition. Intensity (how hard each session is), frequency (how often an athlete is training) and duration (the length of each session). Given most professional athletes, cyclists included, will typically train 6-7 times a week year-round (excluding rest periods) the main influences on load are the intensity and duration of training.

Increases in intensity and duration, whether due to a heavy training period or a competition, ramp up production of cortisol, commonly known as the stress hormone. Cortisol along with other hormones released during excessive training suppress the immune system, increasing the risk of illness.

 

bjsports-2016-096572f01https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5013087/

 

Most studies indicate that about 50% of these illnesses in athletes affect the respiratory tract, a tract that happens to be quite important for … respiration. The fluid loss associated with such infections also causes a temporary reduction in stroke volume and cardiac output. The resultant decrease in maximal oxygen uptake reduces endurance capacity. Not only is less oxygen making it to the muscles but some of these illnesses have also been shown to impair muscle enzyme activity and metabolic function.

heart-2607178_1280
Image Credit: StockSnap via Pixabay

These studies are great, but they’ve basically just confirmed what we all knew ourselves: cop a nasty cold or flu and you’ll be feeling rubbish and going slow. A fact uncovered by research that people seem less likely to accept on their own is that the decrease in performance related to these Upper Respiratory Tract Infections can last for up to 4 days after full recovery from the illness itself.

The outlook so far isn’t great and you’d be forgiven for thinking of giving training a miss for the next year or two, just in case… However, studies on load have found that there is an optimal level of training to maximise immune function and prevent illness, do nothing and you’re putting yourself at the same risk as someone driving themselves into the ground. An interesting find in the last few years is that athletes at the top of their sport often don’t experience the same number of infections as the weekend warrior would with the same load. Part of this may be the years of progressively increasing their training to get to that level. Another hypothesis is that simply to be that good you must be naturally good at handling heavy training load.

 

bjsports-2016-096572f02https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5013087/

 

 

The relationship between training load and illness isn’t quite as straightforward as the above diagram may suggest. Psychological stressors within or external to an athlete’s sport (e.g. lack of sleep, keeping the wife/husband happy, missing the rent deadline for the 4th week in a row) also have a similar effect on cortisol to exercise, only this stress won’t give you any long-term physiological gains (if only). Another major contributor to illnesses in elite athletes is frequent and prolonged international travel, with travel across more than four time zones causing 2-3 times the risk of infection.

airport-2373727_1280.jpg
Image Credit: JeSHOOTS-com via Pixabay

With these studies in mind there’s a few easy ways to give yourself less chance of getting sick:

  • Avoid contact with sick people (No s***)
  • Wash hands before eating
  • Avoid sharing drink bottles/cups/cutlery/towels with others
  • Avoid excessive alcohol consumption as this impairs immune function
  • Carry a disinfectant soap with you during international travel
  • Avoid sudden dramatic changes (>10% difference) in training load
  • Reduce training load if there are high levels of psychological/exterior stress

Even if you’ve taken in all the information, planned your training out with a coach and think everything’s gone right there’s going to be times you’re straight up unlucky and get sick the week before your big event, that’s sport. It’s important to remember the physiological changes from a few days off are a lot smaller than those from a full-blown virus attacking an immune system that’s defeated from heavy training. There’s no point rushing straight back into hard efforts or a race in the few days after an illness as your cardiovascular system will still be stuck on struggle street. Rest up, ‘take your medicine’ and wait until the day after you feel like you’re ready to go again before getting back into it. You’ll likely find you’ve lost a lot less fitness than you’d expect, and your immune system will thank you later.

df089540-a8d7-4ca7-acc4-30da2dc59c42.JPG
2018 U23 Road World Championships, Innsbruck, Austria. I’d come off a big race block in Belgium and received a last minute call-up to worlds. I then had to find a bike to hire the day before flying out as my current training bike wasn’t rideable with parts left in Belgium. This stress followed by a few long travel days meant I wound up sick in the week leading up to the race and was a long way off my best.

Further reading:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5013087/

 

Funnily enough I did most of the research on this topic during back to back tours in New Zealand and the Herald Sun Tour. Sifting through the papers I decided it would definitely be a good idea to take an easy week after a big January. A few tantalising ride invitations from mates later and I ended up doing three five-hour rides, two in the rain, ending up crook as a dog by Sunday. I’ll be locking myself in the house the next few days to properly recover and be good to go come Melb-Warrnie this Saturday. Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Request a Topic

Want to know the results of research on a particular topic of interest? Any questions about a supplement, food or intervention you’ve heard is the next big thing? Leave a question or a topic suggestion in the comments and I’ll sift through the papers for you.

A$10.00

Finnish Saunas to Finish First. Could passive heat acclimation build the freeway to form?

Saunas have been a hot health topic for decades now, with a bucket load of claimed benefits ranging from improving skin, sleep and general relaxation. Research on athletes shows that the adaptations from sweating are even sweeter for endurance performance than expected.

 

sauna-3322351_1920
Image Credit: monika1607 via Pixabay

 

The most significant impact of saunas for athletes is the increased oxygen delivery to working muscles. There are two key components of blood most important for this job: red blood cells (RBCs) and blood plasma. You can think of a blood vessel from the heart to the muscles as a freeway from a city towards towns. In order to move more people (oxygen) you can either put more cars (RBCs) on the road or build more lanes (plasma) for the cars to move quickly along.

 

blood-1813410_1920.jpg
Image Credit: qimono via Pixabay

 

The sweating that occurs in a sauna results in substantial dehydration which ramps up the renin-angiotensin-aldosterone system in the kidneys. This causes reabsorption of sodium into the blood vessels which leads to an increase in blood plasma, more lanes on the freeway. Repeat sauna sections can increase plasma volume by around 10%.

 

highway-1031149_1920
Image Credit: Free-photos via Pixabay

 

Not only can saunas help aid in the transport of RBCs but they may also result in more RBCs being produced, more cars on the road. The increase in plasma results in hemodilution (aka thinner blood) which can lead to a natural secretion of erythropoietin (EPO) and higher RBC count. The higher blood volume leads to heart adaptations including a greater stroke volume and hence lower heart rate at a given power output for cyclists. More cars on the road and more lanes to move those cars means a lot of people can leave the city, a lot more oxygen is reaching the muscles. This is shown in athlete studies by increased VO2max, peak power outputs over given intervals and even time trial performance after passive heat acclimation.

Outside of the blood vessels, repeat exposure to passive heat stress also provides more widespread physiological benefits. Elevated body temperature increases expression of heat shock proteins (my second favourite kind of HSP) which can upregulate circulating factors, increasing cellular protection and triggering the release of human growth hormone. Anyone who has paid attention to professional cycling since the turn of the millennium understands a natural means of boosting EPO and growth hormone release is going to make more than just your arm strong.

 

12002308455_0043cd4d3b_o
Image Credit: Dale Frederick via Flickr

 

The most obvious benefit of heat acclimation is … acclimation to heat. Heat adaptation broadens the critical range at which an athlete’s core temperature can lie without affecting performance. Athletes also develop improved thermoregulatory responses including better circulation and higher sweat rate, aiding in cooling. Plus, there’s no doubting the psychological benefit of getting comfortable being bloody hot.

IMG_2702.JPG
World University Championships, Philippines, 2016. Hot

Saunas seem a sure-fire way to boost your cardiovascular fitness, ability to deal with heat and your general health and well-being and there’s no strong evidence for any health risks for healthy adults.

Hot tips for best results:

  • A typical Finnish sauna is 80-90°C and 10-15% humidity.
  • Heat stimulus should ideally be at least 30min per session (this can be in multiple bouts).
  • Avoid drinking any water in the sauna or in between bouts, the dehydration is a key player in the benefits!
  • Ideally heat acclimation should take place as soon as possible after an exercise session.
  • Heat-acclimatised athletes will need to hydrate more after sauna sessions or training/races than regular athletes due to increased sweat response.
  • Only 6-7 exposures are required to produce physiological and performance benefits.
  • Heating sessions should not be undertaken by athletes who have acute injuries, oedema, vascular disease, wounds, or infections.

 

I’m currently writing this on the bus ride with the team from Palmerston North to Cambridge, NZ. EvoPro just finished our first race and it couldn’t have gone much better, getting teammate Luke Mudgway up for the win in his home town and myself in third. Read all about it on my facebook page. Next up is the 5-day New Zealand Cycle Classic starting tomorrow. I won’t be hitting the sauna in between stages but hopefully the adaptations from heat acclimation sessions back home before heading over the ditch will hang around and we can get some more results this week. Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Cheers,

Cyrus

Request a Topic

Want to know the results of research on a particular topic of interest? Any questions about a supplement, food or intervention you’ve heard is the next big thing? Leave a question or a topic suggestion in the comments and I’ll sift through the papers for you.

A$10.00

Ice, Ice, Maybe… But probably not. The science has gone cold on ice baths for recovery.

Recent science tells us the supposed benefits of ice post-exercise are not all they’re cracked up to be, and that the short-term shrinkage isn’t giving any long-term gains.

 

ice bathImage Credit: Tomas Tomas via Flickr

Sprinters, climbers and café racers are all looking for the best way to recover before their next training session, competition or speed-sign sprint. In the past, it was widely recommended that ice baths post-training or competing was an easy and cost-effective way to do this. Just like a standard bath – only crunchy.

 

‘I read this article that said I should do it’

A bunch of websites targeting athletes from all walks, runs and powerlifts of life have claimed that using ice baths will increase blood circulation, reduce inflammation, and even improve overall muscle function… Unfortunately, new research suggests the only change you’ll see is a reduced hot water bill.

 

Scientists have just made their way to the deep end

Ice baths have been put under the blow torch over the last few years from a whole squad of researchers. The aim was to wash away some of the not so solid facts on just how beneficial post exercise cold water immersion can be. They looked at the effect on blood circulation, inflammatory markers (a good indicator for how much ‘ow my legs’ you feel the days after a hard session), and the overall effect on exercise performance in the days post ice bathing.

 

The Cold Truth

All credible recent studies have agreed that cold water’s effect size on recovery is about the same as it’s freezing point (0 for those playing at home). Not only has the recent research shown that jumping in an ice bath after each training session is a waste of time (and water), it might put a freeze on your recovery all together.

 

Surely it can’t hurt, right?

Wrong. Some studies showed ice baths decreased blood circulation (makes sense when you watch an ice-bath victim quickly resemble the skin-tone of a snowman). This is a big no-no as it prevents muscle repair and removal of nasty by-products after high intensity exercise. Even if it lived up to the claims of reducing inflammation this wouldn’t be a win. Inflammation within muscles is the necessary evil which then allows for muscle repair and rebuilding, resulting in those ever-elusive gains. Lose the inflammation, lose the gains.

 

No gains.jpgImage Credit: Chris Stymac via Flickr

I find it a little odd that ice baths have been used unnecessarily for so long, especially considering there are no obvious brands keeping the myth afloat for their own financial benefit (the main players making big money off ice sales are not working in the sports industry…).

ice dealerImage Credit: Hello Chicago via Flickr

Best to bin the bath post-exercise and go with little recovery spin to the café followed by a nice cold drink from your esky full of fresh, unused ice.

 

Still haven’t warmed to the facts? Try these:

https://www.auckland.ac.nz/en/about/news-events-and-notices/news/news-2017/02/ice-baths-no-good-for-muscle-recovery.html

http://www.bbc.com/future/story/20161209-do-athletes-need-to-take-ice-baths

https://www.outsideonline.com/1971446/recovery-ice-bath-isnt-always-such-good-idea

 

I’m into my last few training days before flying to NZ to kick off a big racing block. An ice bath would definitely be welcomed at the end of some big days on the road in the low 40s but I’ll have to cop the heat to max out those gains in preparation for the next few races. Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Cheers,

Cyrus

 

© Cyrus Monk 2019

Request a Topic

Want to know the results of research on a particular topic of interest? Any questions about a supplement, food or intervention you’ve heard is the next big thing? Leave a question or a topic suggestion in the comments and I’ll sift through the papers for you.

A$10.00

Antioxidants or Antibenefits? Why Free Radicals are the unsung hero for athletes

‘Antioxidants’ is a word we see smattered all over breakfast cereal and juice packaging, but new research is telling us that athletes might need to lay off the goji berry extract if they want the most out of their training.

antioxidantsImage Credit: PracticalCures.com

The goodies

Antioxidants have received a more than decent wrap from the food and supplements industry. They’re talked up as being able to help with all kinds of medical conditions, from helping with eye-sight and joint function, to preventing Alzheimer’s disease and cancer.  This hype is great for the companies selling products rich in antioxidants, but it pays to know a little about just what antioxidants are and how they work before you buy a few hundred punnets of blueberries.

The baddies

Every hero needs a villain, and in this tale the villains are a type of free radical known as reactive oxygen species. Reactive oxygen species oxidise stuff, this is bad. Antioxidants antioxidize stuff, this is good.

The story should be straightforward, more heroes and less villains and the greater good prevails? Not quite, like any good superhero story this one has a twist… When it comes to exercise our radical villains play an important role, just enough to make you think twice about whether to barrack for them or the hero.

free radical‘Free Radical’ by Kelly Frew via Flickr

What happens when you train?

Radicals build up within the muscle during intense exercise. Basically, the more oxygen consumed by the muscle, the more oxidative stress from reactive oxygen species (radicals). The stress caused from the radicals then causes damage to the muscle. Now this damage isn’t exactly making our villain sound any more heroic, however, these small amounts of damage are crucial for athletes to see the benefits from their training.

Free Radicals are actually pretty radical

The presence of these radicals causes the release of signals within the muscle telling the muscle to repair itself and better prepare for future oxidative attacks. Think of it like a bunch of bad guys attacking a city. The bad guys don’t do enough to destroy the city completely, the city rallies together, fixes the broken buildings and builds some better walls to defend against the next attack.

Free Radicals do a little damage to the muscle during training so the muscle can repair and become better equipped for the main competition.

Castle.jpgImage Credit: Destinations Journey via Flickr

So, radicals aren’t all bad, but what’s wrong with antioxidants?

If there’s too many heroes around, the villains never make it to the city. This is fine if you’re happy in a small town that will never face attack. But if you’re an athlete you’re striving for a big, powerful fortress that can cope with anything. If the muscle never faces oxidative stress then there is nothing to promote repair and improvement. In the presence of too many antioxidants all that hard training could be going to waste!

I just ate a cranberry; will I have any muscle left by tomorrow?

As is the case with almost all nutrients in the diet: moderation is key. There is still a long list of benefits associated with antioxidants. This new research suggests for athletes to get the most out of their sessions it may be best to avoid overdoing the vitamin supplements and go easy on the goji berries in your post-workout smoothie.

goji berriesGoji Berries. Image Credit: Leslie Degner via Flickr

Further reading:

http://www.abc.net.au/science/articles/2014/11/12/4124033.htm

http://sciencebasedmedicine.org/antioxidants-and-exercise-more-harm-than-good/

https://medlineplus.gov/antioxidants.html

http://www.webmd.com/food-recipes/20-common-foods-most-antioxidants

 

My first race with the team will be the Gravel and Tar Classic next week in New Zealand. Hopefully a good week of training and watching the antioxidant intake will have me ready to go! Until then, I’ll keep reading the research papers so you can spend more time on the bike.

Cheers,

Cyrus

© Cyrus Monk 2019