RESEARCH: studies reviewed this week - 6 July 2020 to 12 July 2020

NUTRITION: Carbohydrate Ingestion Immediately Before Exercise Does Not Improve 20 Km Time Trial Performance in Well Trained Cyclists

Previously I shared a protocol of a high-fat meal on the morning of a race followed by 400kCal of CHO immediately before the start. While the previous study was looking at a certain intervention there was some discussion when I shared it about the pre-race CHO intake possibly being the important factor in the improved performance. This study looks at a shorter duration time trial (TT) test so it's not exactly comparable, but it does provide some ideas and indication of that to do before a shorter race. The study found that:

The average power output and heart-rate during the two rides did not differ between treatments. Accordingly, the performance times for the two TT's were the same.
We conclude that the ingestion of approximately 40 g of carbohydrate does not improve maximal cycling performance lasting approximately 30 min, and that carbohydrate availability, in the form of circulating blood glucose, does not limit high-intensity exercise of this duration.

PRACTICAL TAKE AWAY - for shorter races it's not necessary to ingest CHO immediately before the start.

TRAINING: Improved VO2max and Time Trial Performance With More High Aerobic Intensity Interval Training and Reduced Training Volume

This is quite an unusual study and it was performed with just one athlete, however, I found it particularly interesting to think about how to train in the off-season. This cyclist did way more running in the off-season than he usually did and as I runner I think about doing more cycling in the off-season (but on an indoor trainer). However, despite changing the modality and decreasing the training volume, with the right training the athlete was able to improve fitness metrics that were transferable to his sport. It's worth reading and I've provided most of the abstract below to provide some of the details of what was studied:

The present study investigated to what extent more high aerobic intensity interval training (HAIT) and reduced training volume would influence maximal oxygen uptake (VO2max) and time trial (TT) performance in an elite national cyclist in the preseason period.
Total monthly training volume was reduced in the 2011 preseason compared with the 2010 preseason, and 2 HAIT blocks (14 sessions in 9 days and 15 sessions in 10 days) were performed as running. Between the HAIT blocks, 3 HAIT sessions per week were performed as cycling. From November 2010 to February 2011, the cyclist reduced total average monthly training volume by 18% and cycling training volume by 60%.
In conclusion, preseason reduced total training volume but increased amount of HAIT improved VO2max and TT performance without any changes in cycling economy. These improvements in cycling appeared despite that the HAIT blocks were performed as running. Reduced training time, and training transfer from running into improved cycling form, may be beneficial for cyclists living in cold climate areas.

PRACTICAL TAKE AWAY - fitness is fitness and doing what you can in a different sport in the off-season may be enough to set up the season ahead.

NUTRITION: Gut-training: The Impact of Two Weeks Repetitive Gut-Challenge During Exercise on Gastrointestinal Status, Glucose Availability, Fuel Kinetics, and Running Performance

Recently I have been following the work of Aitor Viribay Morales very closely. He has done some studies that show the ability to consume up to 120g/hr of CHO by athletes and that this benefits performance. He also shares an excellent gut-training protocol that takes between six and eight weeks to achieve this level of consumption. While I believe in Aitor's research, sometimes athletes only start thinking about their gut training closer to a race and I was unsure about whether this type of protocol could be applied on a shorter basis. This study looked into two weeks of gut-training to see the impact:

Participants were then randomly assigned to a carbohydrate gel-disc (CHO-S), carbohydrate food (CHO-F), or placebo (PLA) gut-training group for 2 weeks of repetitive gut-challenge intervention.
Gastrointestinal symptoms reduced in the second test after the intervention on CHO-S and CHO-F; reductions were greater than PLA. Distance test improved on CHO-S (5.2%) and CHO-F (4.3%), but not on PLA (-2.1%). Two weeks of gut-training with CHO-S and CHO-F improved gastrointestinal symptoms and running performance compared with PLA. CHO-S also reduced malabsorption and increased blood glucose availability during endurance running compared with PLA.

PRACTICAL TAKE AWAY - a two-week intervention is enough to see benefits of gut-training on performance.

NUTRITION - Menthol as an Ergogenic Aid for the Tokyo 2021 Olympic Games

This consensus paper investigated current research and data about using menthol in hot conditions. The aims of the paper were to explore this intervention ahead of the Tokyo Olympics:

Menthol topical application and mouth rinsing are ergogenic in hot environments, improving performance and perception, with differing effects on body temperature regulation. Consequently, athletes and federations are beginning to explore the possible benefits to elite sport performance for the Tokyo 2021 Olympics, which will take place in hot (~ 31 °C), humid (70% RH) conditions. There is no clear consensus on safe and effective menthol use for athletes, practitioners, or researchers. The present study addressed this shortfall by producing expert-led consensus recommendations.

In the section of the potential benefits of using menthol, the authors found:

  • Single and repeated menthol topical applications and mouth rinsing reliably improve thermal sensation and, to a lesser extent, thermal comfort and RPE during exercise in a hot environment.
  • Menthol topical application may beneft activities where heat tolerance is limiting, but may increase the risk of heat-related illness.

PRACTICAL TAKE AWAY - it may be worth experimenting with menthol of mint flavored drinks in hot conditions. Sponser in Switzerland provides its competition drink in a cool mint flavor and Science in Sport in England provides a drink has menthol extract.

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