Hormonal Response to Exercise, Revisited: A Consequence, not a Determinant of Your Mood, Effort & Performance
|Studies in men suggest no effect of the hormonal response on training outcome - What about women? A news study provides insights that may be relevant for both female and male gymrats.|
That's stupid stubbornness, nothing else, right? Well, even though I don't believe in ghosts, I have to admit that a closer look at West's data will have you reject the hypothesis that the post-workout testosterone response would augment size gains, it does yet also show other hormonal changes do correlate with the changes in the study's subjects' lean mass (Figure 1, left) as well as type I (middle) and type II fiber size increases (Figure 1, middle & right).
|Figure 1: Sign. associations between PWO hormone levels and lean mass, as well as fiber size increases (West. 2012).|
|Figure 2: Changes in anabolic and catabolic hormones in response to AM and PM HIIT and RT training (Toon. 2015).|
|Higher sprint cadence (RPM) during HIIT, higher increase in DHT in the female study participants (Toon. 2015).|
"[...] it could be beneficial to perform resistance training in the afternoon preceded by interval exercise in the morning in order to stimulate a hormonal milieu that may be more conducive to stimulating muscle protein turnover" (Toon. 2015).If you scrutinize the data in Figure 2, you can see that this hypothesis is warranted, because of the differential response of the anabolic hormones, testosterone and IGF-1, and the stress / catabolic hormones, cortisol and prolactin, she observed in her young female subjects. Against that background it is quite interesting that Toone's last and most important experiment, in which she investigating the potential acute effects of hormones on performance, failed to demonstrate a direct correlation between changes in testosterone or other "anabolic" hormones and her subjects' performance.
"The trial consisted of a 20 min effort at a target power of 80% of the average power obtained during the maximal 20 min TT, followed by a 5 min break, before completion of a bout of repeated sprint interval cycle exercise consisting of 10 x 30 s sprinting, with 90 s recovery. The session was self-paced with real-time numerical feedback provided on elapsed time, cadence and power. Participants were given verbal encouragement at specific time-points throughout the trial. The same protocol was repeated for the second main trial one week later. Participants were permitted to drink water ad libitum throughout the trials. Trials were completed in a group setting as a group of six and a group of eight. A trial timeline schematic is displayed [in Figure 3]" (Toon. 2015).Instead, the results of the previously described exercise test point towards affective variables, i.e. mood and effort, as the factors that mediate any link between hormonal changes and performance markers during an acute bout of high intensity cycling.
|Figure 3: Design of the last and most important experiment of the study (Toone. 2015).|
|Figure 4: The hormonal response is rather the consequence than the trigger of acute performance.|
- Phillips, Stuart M. "Strength and hypertrophy with resistance training: chasing a hormonal ghost." European journal of applied physiology 112.5 (2012): 1981-1983.
- Toone, Rebecca. Assessing the Hormone Response to High Intensity Exercise and Identifying Associations with Performance. Diss. University of Bath, 2015.
- West, Daniel WD, and Stuart M. Phillips. "Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training." European journal of applied physiology 112.7 (2012): 2693-2702.