RESEARCH: studies reviewed this week - 7 September 2020 to 13 September 2020

SLEEP: Effects of Sleep Deprivation on Acute Skeletal Muscle Recovery after Exercise

Last week I shared some studies about sleep extension and it's benefits for performance. This study looked into sleep deprivation and aimed to "evaluate whether total sleep deprivation after eccentric exercise-induced muscle damage (EEIMD) modifies the profiles of blood hormones and cytokines". The methodology involved two groups:

In the first condition a "muscle damage" protocol was followed by 48 h of total sleep deprivation and 12 h of normal sleep (DEPRIVATION). In the other condition, the same muscle damage protocol was conducted, followed by three nights of regular sleep (SLEEP).

The authors found that:

Muscle voluntary contraction and serum creatine kinase increased equally over the study period in both conditions. From the cytokines evaluated, only IL-6 increased in DEPRIVATION. No differences were detected in testosterone levels between conditions, but IGF-1, cortisol, and cortisol/total testosterone ratio were higher in DEPRIVATION.

PRACTICAL TAKE AWAY - while sleep deprivation does not delay muscle strength recovery, it does seem to impact inflammatory and hormonal responses suggesting it may have impacts on long term training adaptation.

STRENGTH: Explosive-strength training improves 5-km running time by improving running economy and muscle power

Plyometrics and explosive strength exercises are known to improve running economy. This study set out to confirm that and to identify whether or not these exercises help to improve performance. The protocol used was:

The total training volume was kept the same in both groups, but 32% of training in experimental (E) and 3% in control (C) was replaced by explosive-type strength training. A 5-km time trial (5K), running economy (RE), maximal 20-m speed (V20 m), and 5-jump (5J) tests were measured on a track.

The authors found that:

The 5K time, running economy, and maximal velocity improved in E, but no changes were observed in C.

The present simultaneous explosive-strength and endurance training improved the 5K time in well-trained endurance athletes without changes in theirV˙o2 max.

Improvement was due to improved neuromuscular characteristics that were transferred into improved maximal velocity and running economy.

PRACTICAL TAKE AWAY - plyometrics and explosive strength improve performance even when substituted for some endurance training. This is consistent with a previous study I shared that showed plyometrics helped improve running economy in ultramarathon runners too. Do your plyometrics and strength training!

ALTITUDE: Altitude Training and Recombinant Human Erythropoietin: Considerations for Doping Detection

I found this study quite interesting because it starts with a set of qualifications that altitude training benefits are "equivocal". The authors then go on to say that:

Altitude training may affect an athlete’s hematological parameters in ways similar to those observed following blood doping.

Current methods of detection appear insufficient to differentiate between altitude training and blood doping making the interpretation of an athlete’s biological passport difficult.

Top athletes are using altitude training because they believe it works and athletes who are blood doping are using an illegal aid to benefit their performance (there would be no reason to take the risk if it didn't help). If it is difficult to distinguish between the two it seems that both must be providing some sort of benefit to performance.

PRACTICAL TAKE AWAY - altitude training seems to provide the same benefit as blood doping and is therefore a worthwhile and legal means of improving performance.

NUTRITION: Potato ingestion is as effective as carbohydrate gels to support prolonged cycling performance

Race nutrition is critical to performance in endurance events and CHO products have shown to have significant benefit for improving performance. Most studies and most athletes use commercial sports nutrition products such as drinks, gels and bars. This study "investigated the effects of potato purée ingestion during prolonged cycling on subsequent performance vs. commercial CHO gel or a water-only condition". This is an interest use case because often ultramarathon athletes have flavor fatigue or are unable to stomach those commercial CHO products later in a race.

The authors found that:

  • Blood glucose concentrations were higher in potato and gel conditions compared with water condition.
  • Blood lactate concentrations were higher after the TT completion in both CHO conditions compared with water condition.
  • TT performance was improved in both potato and gel conditions compared with water condition.

PRACTICAL TAKE AWAY - potatoes are effective race nutrition and provide equivalent CHO compared to commercial gels and drinks.

NUTRITION: Maximizing Post-exercise Anabolism: The Case for Relative Protein Intakes

How much protein should you take for recovery? I've often seen recommendations that 20g post-training is ideal and most recovery drinks have 20g per serving. This review starts out with the hypothesis that "it is unclear if these absolute protein intakes can be viewed in a 'one size fits all' solution". The author reviewed the published literature and found that:

A relative single meal intake of ~0.31 g/kg of rapidly digested, high quality protein (i.e., whey) should be considered as a nutritional guideline for individuals of average body composition aiming to maximize post-exercise myofibrillar protein synthesis while minimizing irreversible amino acid oxidative catabolism that occurs with excessive intakes of this macronutrient.

PRACTICAL TAKE AWAY - protein post exercise is important and adjusting to your body size may be valuable. Aim for 0.31 g/kg.

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