RESEARCH: studies I shared this week: 21 to 27 November 2022

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

PHYSIOLOGY: Cardiovascular response to prescribed detraining among recreational athletes


  1. We therefore studied recreational runners (n = 21, age 34 ± 7 yr; 48% male) who completed an 18-wk training program (~7 h/wk) culminating in the 2016 Boston Marathon after which total exercise exposure was confined to less than 2 h/wk (no single session greater than 1 h) for 8 wk.
  2. Two distinct phases of myocardial remodeling and hematological adaptation were observed.
  3. After 4 wk of detraining, there were significant reductions in plasma volume (PV), left ventricular (LV) wall thickness, LV mass, and right atrial area.
  4. After 8 wk of detraining, there was a significant reduction in right ventricle chamber size without further concomitant reductions in PV or LV wall thickness.

PRACTICAL TAKEAWAY - within just four weeks after stopping training, we already see changes in the heart. Therefore, make sure to maintain your exercise routines and achieve a minimal dose per week even in the off-season.

STRENGTH: The Effects of Unilateral Resistance Training on Muscular Strength, Power, and Measures of Core Stability in Resistance Trained Individuals


  1. To examine the effects of unilateral resistance training on lower body power, muscular strength, and measures of core stability in resistance-trained college students.
  2. Participants underwent 10 sessions of either unilateral (UL) or bilateral (BL) resistance training on three non-consecutive days per week for three weeks.
  3. There was a significant (p≤ 0.05) main effect of time across all variables, such that both groups improved scores on 1-RM leg press, standing vertical jump (VJ) for lower body power, and double leg lowering (DLL), hip abduction isometric strength (HAIS), and Sorensen (SOR) tests for core stability.
  4. Additionally, the magnitude of improvement (Cohen’s d) was larger in UL for all variables except VJ, which was larger in the BL group.

PRACTICAL TAKEAWAY - unilateral resistance training is as effective as bilateral training and may result in better core stability variables.

PHYSIOLOGY: Slow component of VO2 kinetics: mechanistic bases and practical applications


  1. The VO₂ slow component, a slowly developing increase in VO₂ during constant-work-rate exercise performed above the lactate threshold, represents a progressive loss of skeletal muscle contractile efficiency and is associated with the fatigue process.
  2. There is strong evidence that, during constant-work-rate exercise, the development of the V·O₂ slow component is associated with the progressive recruitment of additional (type II) muscle fibers that are presumed to have lower efficiency.
  3. Recent studies, however, indicate that muscle efficiency is also lowered (resulting in a "mirror-image" V·O₂ slow component) during fatiguing, high-intensity exercise in which additional fiber recruitment is unlikely or impossible.
  4. Several interventions can reduce the magnitude of the VO₂ slow component, and these are typically associated with an enhanced exercise tolerance.
  5. These include endurance training, inspiratory muscle training, priming exercise, dietary nitrate supplementation, and the inspiration of hyperoxic gas.

PRACTICAL TAKEAWAY - there is potential to improve performance through training to reduce the magnitude of the VO2 slow component. For athletes, endurance training and inspiratory muscle training look like promising interventions.

PHYSIOLOGY: Myocardial response to incremental exercise in endurance-trained athletes


  1. Recent evidence indicates that endurance-trained athletes are able to increase their stroke volume (SV) throughout incremental upright exercise, probably due to a progressively greater effect of the Frank-Starling mechanism.
  2. Left ventricular function was assessed throughout incremental exercise in the supine and upright positions (counterbalanced) using radionuclide ventriculography.
  3. Stroke volume increased in a linear fashion during incremental exercise in both the upright and supine positions. The increases in cardiac output (Q) throughout incremental to maximal exercise (in both the supine and upright positions) were significantly related to changes in heart rate, myocardial contractility and the Frank-Starling mechanism.
  4. We conclude from this investigation that highly trained endurance athletes are able to make progressively increasing usage of the Frank-Starling effect throughout incremental exercise.

PRACTICAL TAKEAWAY - one of the reasons to do continuous VO2 max intervals (3-5') is to ensure that there is a sufficient preload stimulus to encourage greater contractile force through the Frank-Starling effect. This study seems to indicate that well trained athletes are able to make better use of this effect.

TRAINING: Effect of respiratory muscle training on exercise performance in healthy individuals


  1. Two distinct types of specific respiratory muscle training (RMT), i.e. respiratory muscle strength (resistive/threshold) and endurance (hyperpnoea) training, have been established to improve the endurance performance of healthy individuals.
  2. The multiple linear regression analysis including 46 original studies revealed that less fit subjects benefit more from RMT than highly trained athletes and that improvements do not differ significantly between inspiratory muscle strength and respiratory muscle endurance. training
  3. With increasing test duration, improvements in performance are greater and the type of sport does not influence the magnitude of improvements.
  4. RMT improves endurance exercise performance in healthy individuals with greater improvements in less fit individuals and in sports of longer durations.

PRACTICAL TAKEAWAY - respiratory muscle training is probably a valuable addition to an endurance training plan.

SUPPLEMENT: Effects of ibuprofen during 42-km trail running on oxidative stress, muscle fatigue, muscle damage and performance


  1. Up to 75% of marathon runners ingest non-steroidal antiinflammatory drugs (NSAIDs) during competition.
  2. We evaluated the effect of ibuprofen (IBU) use on oxidative stress, muscle damage, physical performance, and vertical jump of runners participating in a 42-km trail running.
  3. A 400-mg IBU capsule was administered to the IBG 15 min prior to the start of the trial and during the course after 5hrs.
  4. The main findings of the present study were as follows: (1) The use of IBU had a significant effect on oxidative stress as well as on squat jump (SJ) and (2), in contrast IBU had no influence on physical performance.

PRACTICAL TAKEAWAY - there isn't any performance benefit to taking ibuprofen and there are definitely potential downsides to taking NSAIDs so I would recommend not using these during trail running races.

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