RESEARCH: studies reviewed this week - 10 August 2020 to 16 August 2020

NUTRITION: Omission of a carbohydrate-rich breakfast impairs evening endurance exercise performance despite complete dietary compensation at lunch

Missing breakfast or following an intermittent fasting protocol where no food is consumed in the morning is known to impair performance in evening training sessions. However, this study set out to determine whether "this is due to breakfast omission per se, or secondary to lower carbohydrate intake over the day". That is, is it missing a meal at breakfast time even if the same calories are consumed during the day, or is it due to eating less over the day when breakfast is missed.

Eleven highly trained cyclists completed two trials: breakfast (B) and no breakfast (NB). During B, participants consumed an individualised breakfast, whilst during NB participants fasted until 12pm and then consumed a standardised lunch. The overall energy and macronutrient profile was identical in both trials, with timing the only difference.

The findings were that:

Mean power output during a 20 km time trial performed in the evening was ∼3% lower in NB compared to B.

No differences in heart rate, blood glucose or blood lactate concentrations were apparent, but perception of effort appeared to be higher in the early stages of the time trial in NB compared to B despite lower power output.

Impaired high-intensity endurance performance in the evening following breakfast omission is related to meal timing rather than carbohydrate intake / availability.

PRACTICAL TAKE AWAY - a high CHO breakfast is important for high-intensity sessions no matter what time of the day the training session takes place. Eat a high-quality, high-CHO breakfast on your hard days.

NUTRITION: A Placebo-Controlled Trial of Riboflavin for Enhancement of Ultramarathon Recovery

I have heard of using B vitamins to improve performance, but as far as I was aware Riboflavin (Vitamin B2) hasn't been investigated for its use in ultramarathon performances. This study looked at "whether acute ingestion of riboflavin reduces muscle pain and soreness during and after completion of a 161-km ultramarathon and improves functional recovery after the event". The dose and protocol used was:

Participants of the 2016 161-km Western States Endurance Run were assigned to receive a riboflavin or placebo capsule shortly before the race start and when reaching 90 km. Capsules contained either 100 mg of riboflavin.

The results showed that:

Muscle pain and soreness ratings during and immediately after the race were found to be significantly lower (p = .043) for the riboflavin group. Analysis of the 400-m run times also showed significantly faster (p < .05) times for the riboflavin group than the placebo group at post-race days 3 and 5.

This preliminary work suggests that riboflavin supplementation before and during prolonged running might reduce muscle pain and soreness during and at the completion of the exercise and may enhance early functional recovery after the exercise.

PRACTICAL TAKE AWAY - ribloflavin may reduce muscle pain and aid recovery. Consider taking a riboflavin supplement before and during your ultramarathon events.

PSYCHOLOGY: Elite athletes' attitudes towards the use of placebo-induced performance enhancement in sports

This study investigated "athletes' experiences with and attitudes towards the use of placebo for performance enhancement". The findings were positive towards placebo use:

47% of the athletes have experienced placebo effects in the past.

A majority of the athletes (82%) thought that placebos could affect their sports performances.

Regardless of past experience with placebo, more than half of the athletes (53%) would accept an unknown but legitimate substance from the coach, and 67% of them would not mind a placebo-linked deception if that was effective.

PRACTICAL TAKE AWAY - elite athletes are known to believe in superstitions and other habits that are proven not to be beneficial. However, their belief in placebo benefits shows that it may be a mental model that can enhance performance. If there is something you believe can help your performance (and as long as it is not going to distract or decrease performance) then there may be some benefit to continuing that practice.

No comments: