Training & Performance

A new study from the Australian Institute of sport has put another nail in the coffin for the ketogenic diet for endurance athletes. High fat, very low carb diets have been touted as potentially increasing endurance performance for a number of reasons; we store more fat in our body than we could ever store carbohydrate, it has been proposed as ‘anti-inflammatory’, and it has even been suggested to help our muscles respond more to a given exercise stimulus. (If you’re not sure what a ketogenic diet is, we’ve written about it before with some examples)

To put it to the test though, the renowned Australian research group enlisted elite race-walkers (Olympic and world medalists were amongst the participants) and got them to consume either a high carbohydrate, a structured carbohydrate, or a ketogenic diet. They carried this study out and published the data a few years ago. They found that when the athlete’s performance in a race was worse when they had the ketogenic diet compared to the other two. When they assessed them in the lab, they found it cost them more energy to exercise at higher intensities – so their exercise economy was worse. 

After publishing the data, they decided they would rerun the experiment to try and see if they could confirm the data.

New Angle, Same Result

In this new study, the research group again recruited world-class athletes, put them, again, on one of three diets (two high carbohydrates and one were ketogenic). They also ran two simulated races to look at performance effects and assessed the athletes in the lab. What they also did this time allowed athletes on the ketogenic diet to try and load up on carbohydrates before the races to see if they could get the best of both worlds – have better adaptation during training when they are ketogenic, and then the benefit of carbohydrates which are a more economic fuel to use during high-intensity exercise.

The results – the same as they had previously found. Worse performance, and less economic athletes when they consume a high fat, ketogenic diet – even after they had refed briefly with carbohydrates. The reason why we suspect that the carbohydrate did not recuse performance levels, is because the ketogenic diet blunts our ability to store and then burn carbohydrate in the muscle – exactly where it is needed during exercise.

What’s worse for the ketogenic diet is athletes did perform worse – they did not even maintain their pre-training levels. Whereas athletes in both carbohydrate groups improved their performance.

Pre and post-diet race times during 10km time trial. All runners on the ketogenic diet performed worse while both carbohydrate groups saw improvements.

Final Nail In The Coffin?

The results are pretty damning for the ketogenic diet for endurance athletes. But doe that mean there is no place for it at all?

Probably not. For example, a recent case study showed that an international cyclist has long been able to maintain world-class performances on a low carbohydrate diet (although he did improve when he increased his carbohydrate intake in the weeks leading to competition) (2). There are also many athletes across different sports that are reportedly competing while living on a ketogenic diet. Although even in team sports such as football, performance has been seen to be linked to carbohydrate availability.

If you are working with athletes, you need to consider their carbohydrate needs based on competition.

References

1 -Burke, Louise M., Avish P. Sharma, Ida A. Heikura, Sara F. Forbes, Melissa Holloway, Alannah KA McKay, Julia L. Bone, Jill J. Leckey, Marijke Welvaert, and Megan L. Ross. “Crisis of confidence averted: Impairment of exercise economy and performance in elite race walkers by ketogenic low carbohydrate, high fat (LCHF) diet is reproducible.” PloS one 15, no. 6 (2020): e0234027.

 2 – Webster CC, Swart J, Noakes TD, Smith JA. A Carbohydrate Ingestion Intervention in an Elite Athlete Who Follows a Low-Carbohydrate High-Fat Diet. Int J Sports Physiol Perform. 2018;13(7):957–960. pmid:29252062

The human gut is colonized by more than 100 trillion microbiotas, and these bacteria can provide benefits to the individuals. We have written many times about the positive effects of probiotic supplements, but a new study (1) has looked to see the effects of a daily probiotic supplementation on cognitive measures in competitive footballers. The researchers took measures of cognitive function, and brain wave activities at the beginning (before supplementing), and then after 4 and 8 weeks. One group supplemented with Lactobacillus Casei Shirota strain (LcS) and the other supplemented with a placebo.

Probiotics have previously been shown to have positive effects on anxiety and depression

The Results

After 4 weeks, the footballers that had been supplementing with the probiotics had significantly increased theta and delta power from brain wave activities measures.

What Does That Mean?

Well, theta oscillation is one of the slowest brain waves where the frequency was around 4–8 Hz that could detect when an individual felt more relaxed, in a sleeping state or while meditating. This indicated that the football players in the probiotic group were more relaxed with low stress and anxiety.

On the flip side, high delta responses are often associated with cognitive process such as attention, problem solving, perception, and signal tracking. What was even more interesting was that those players with anxiety and depression tended to show slower reaction times in the function tests due to the dysfunction of the process to communicate accurate information accompanied by anxiety and depression.

How does it work?

We know more and more about the gut and the bacteria that reside there, and then all of the different roles they might play. Gut microbiota are functionally diverse and play a role in many basic metabolisms including carbohydrate metabolism, immune system activities, and fibre degradation. But we know are beginning to understand the bidirectional communication between the brain and the gut.

This means that changes in the microbial environment can affect behaviour, and behavioural changes can affect the gut bacteria (2). Gut bacteria and probiotics can directly interact with our nervous system, they can secrete hormones that can be transferred to the brain, and they can reduce systemic inflammation.

The Study In Footballers Concluded That…

“Football is a game where players need to make decisions based on a rapidly changing environment while considering teammates, opponents, as well as the ball. Due to that, players need to intensely focus their attention on the game and maintain the highest physical capabilities to achieve their targets.

Stress, anxiety, and depression are often associated with competitions, and regulating these psychophysiological components can be the solution to improve performance via food-based nutritional supplements. …with supplementation of Lactobacillus Casei Shirota strain, the delta and theta brain waves were higher in the probiotic group after four weeks that provide evidence for relaxation and attention components in the probiotic group.” 

References

1 – Adikari, A. M. G. C. P., Mahenderan Appukutty, and Garry Kuan. “Effects of Daily Probiotics Supplementation on Anxiety Induced Physiological Parameters among Competitive Football Players.” Nutrients 12, no. 7 (2020): 1920.

 2 – Liu, Bangshan, Yunan He, Mi Wang, Jin Liu, Yumeng Ju, Yan Zhang, Tiebang Liu, Lingjiang Li, and Qi Li. “Efficacy of probiotics on anxiety—A meta‐analysis of randomized controlled trials.” Depression and anxiety 35, no. 10 (2018): 935-945.

In this episode we discuss:

– Adapting his business at the start of the covid-19 lockdown.

– Adapting his coaching for both the general public and athletes as well as dealing with their changes in expectations and goals.

– The value of coaching during periods of uncertainty.

For more about Matt, you can find him on Facebook, or learn more about the Tamar Performance Centre where he offers a range of coaching facilities for endurance athletes and triathletes.

If you are taking any prescribed medication or have any medical conditions ALWAYS consult your doctor or pharmacist BEFORE taking vitamins or supplements. Food supplements must not be used as a substitute for a varied and balanced diet and a healthy lifestyle. If pregnant or lactating, ALWAYS consult your doctor before use. Or if you have any queries about any supplement ALWAYS consult a QUALIFIED medical professional.

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When it comes to getting protein in post-training, most people would agree that it is beneficial – whether it is for muscle growth or recovery. But how much is enough? For a long time, it was believed that you needed no more than ~20g of whey protein post-training. But why? And is this still the case?

Studies examining how much (and what type of) protein we should take post-training come from studies that use isotopes to measure how much ‘new’ protein we are able to make in our muscles after training – this is the whole point of training. Earlier studies showed that there was no added benefit for muscle growth beyond 20g of protein – even if you doubled the intake to 40g (1). This did spawn one myth that should be put to bed.

The myth that your body can’t handle any more than 20g of protein in one go needs to be put straight into the bin and never return.

If you consume more protein than this in one sitting, it is just used for other processes within the body. It might go to a vital organ, it can be used for energy production – it is not just wasted.

A New Protein Ceiling

This original work though showing that there is no added benefit for muscle growth beyond 20g stuck for a long time though. That was until two recent studies.

The first study again looked at 20g vs 40g. But, unlike the original study that used a leg only training session, this new study used a whole body resistance training session (2). Their theory was that, as we were using more muscle mass, we would most likely need more protein afterwards. What did they find? A 20% increase in skeletal muscle synthesis when participants took on 40g vs 20g.

So, it appears that how much protein you consume after training or competition might depend on how hard the session was and how much of the body was used. Full body session? You might need up to 40g of protein. Upper or lower body only, you maybe only need around 20g.

Training Into Old Age – More Of The Same?

A very recent study has even shown that 40g may be more beneficial post-training as we age. Unlike the study in younger adults that used tracers to measure protein synthesis after a single training study – this study in older adults wanted to look at the practical effects of consuming either 20g or 40g post training (3). Those in the group consuming 40g post-training showed significantly improved strength performance in chest, shoulder and leg press compared to a matched group that only consumed 20g. Same training – but better results. 

Something to think about as we age.

References

1 – Shing, C. M., Peake, J. M., Lim, C. L., Briskey, D., Walsh, N. P., Fortes, M. B., … & Vitetta, L. (2014). Effects of probiotics supplementation on gastrointestinal permeability, inflammation and exercise performance in the heat. European journal of applied physiology, 114(1), 93-103. 

 2 – Roberts, J. D., Suckling, C. A., Peedle, G. Y., Murphy, J. A., Dawkins, T. G., & Roberts, M. G. (2016). An exploratory investigation of endotoxin levels in novice long distance triathletes, and the effects of a multi-strain probiotic/prebiotic, antioxidant intervention. Nutrients, 8(11), 733.

3 – Suckling, C., Roberts, J., Peedle, G., Gordon, D., Marshall, H., Taylor, L., & Roberts, M. G. (2016). Probiotic Supplementation and Gastrointestinal Endotoxemia Before and After the Marathon Des Sables. Medicine & Science in Sports & Exercise, 48(5S), 249-250.

4 – Pugh, J. N., Sparks, A. S., Doran, D. A., Fleming, S. C., Langan-Evans, C., Kirk, B., … & Close, G. L. (2019). Four weeks of probiotic supplementation reduces GI symptoms during a marathon race. European journal of applied physiology, 119(7), 1491-1501.

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