RESEARCH: studies I shared this week: 25 to 31 July 2022



All of the studies I've shared (~500 studies) are available on the RESOURCES PAGE.



PHYSIOLOGY: Aspects of Respiratory Muscle Fatigue in a Mountain Ultramarathon Race

PRACTICAL TAKEAWAYS -

  1. Maximal voluntary inspiratory and expiratory pressures were significantly reduced after a 110km mountain trail race.
  2. Ultraendurance running reduces respiratory muscle strength for inspiratory muscles shown to result from significant peripheral muscle fatigue with only little contribution of central fatigue.
  3. Inspiratory muscle training may benefit ultramarathon performance (see these tweets: one and two).


NUTRITION: Within-Day Energy Deficiency and Metabolic Perturbation in Male Endurance Athletes

PRACTICAL TAKEAWAYS -

  1. Despite there being no observed differences in 24-hr energy balance or energy availability between the groups, subjects with suppressed resting metabolic rate (RMR) spent more time in an energy deficit exceeding 400 kcal hr and had larger single-hour energy deficits compared with subjects with normal RMR.
  2. Larger single-hour energy deficits were associated with higher cortisol levels and a lower testosterone:cortisol ratio.
  3. Try not to go into a significant energy deficit during the day (eat often if energy demands are high).


TRAINING: Road to Tokyo 2020 Olympic Games: Training Characteristics of a World Class Male Triathlete

PRACTICAL TAKEAWAYS -

  1. The triathlete performed 14.74h of weekly endurance training volume. Training intensity distribution (TID) was 81.93% / 7.16% / 10.91% for zones 1 (low intensity), 2 (moderate intensity) and 3 (high intensity) respectively.
  2. Pyramidal TID model is observed during the initial stages of the periodization and Polarized TID model is observed at the end of the macrocycle.
  3. The triathlete’s peak ⩒O2 was increased by 20% on cycling and by 14% on running. Peak power was increased by 3.13% on cycling test and peak speed by 9.71% on running test.
  4. 4-week altitude training camps and a heat acclimation protocol were used in the lead-up to the games.
  5. This athlete followed good training protocols and research and this resulted in physiological improvements and good racing results.


SLEEP: Sleep Deprivation Training to Reduce the Negative Effects of Sleep Loss on Endurance Performance

PRACTICAL TAKEAWAYS -

  1. A male ultraendurance runner underwent a 6-week sleep deprivation training (SDT) program (consisting of 1 night SD every Sunday) in addition to his regular physical training program before taking part in a 6-day race.
  2. SDT was well tolerated by the athlete. A visual analysis of the data suggests that including SDT in the weeks preceding an ultraendurance competition may have beneficial effects on sleepiness and perceived mental effort in the context of 5 consecutive days of prolonged running and 2 nights of SD.
  3. SDT may be valuable to beneficial for performances that go through the night (see the protocol here and more details here).


HRV: Decision making and heart rate variability

PRACTICAL TAKEAWAYS -

  1. Results show an association between higher vagally mediated HRV and better decision-making performance, especially under risk and uncertainty.
  2. This systematic review highlights the influence of the autonomic nervous system in decision-making processes.
  3. If facing a tough decision, it may be valuable to ensure that you're rested and have a high HRV score.


SUPPLEMENTS: Taurine Supplementation Increases Post-Exercise Lipid Oxidation at Moderate Intensity in Fasted Healthy Males

PRACTICAL TAKEAWAYS -

  1. Different doses of taurine (TAU) (3 g or 6 g) or placebo were supplemented 90 min before a single bout of fasting aerobic exercise.
  2. We observed that TAU supplementation (6 g) increased lipid oxidation (38%) and reduced the respiratory coefficient (4%) when compared to the placebo. However, no differences in lipid oxidation were observed between the different doses of taurine (3 g and 6 g).
  3. Six grams of TAU supplementation 90 min before a single bout of aerobic exercise in a fasted state may increase lipid oxidation post exercise.

No comments: