Bodybuilding coach, Dr. Layne Norton, provides a vivid example of metabolic …show more content…
To this end, testosterone levels drop and cortisol production increases, the latter being shown to oppose the retention of lean mass while also inhibiting the appetite-suppressing effect of leptin (Trexler 2014). Illustrating the significance of these hormones, a 2012 study proposed endocrine factors to be predictors of the success or failure of weight loss attempts, as lower ghrelin and higher leptin baseline levels were anticipatory of lower body mass in female subjects following a twelve-week calorically restricted diet (Labayen 2012). As with thermogenic changes, these adaptations are not short-lived, as data suggest that altered endocrine levels remain even after caloric restriction has ended (Trexler 2014). Hence, the hormonal adaptations associated with metabolic damage represent a long-term threat to the maintenance of lean mass and weight …show more content…
This take-away is supported by three main considerations: the limited magnitude of metabolic adaptations relative to the importance of dietary adherence, the fact that many if not most of the consulted studies utilized extreme circumstances to yield measurable results (either through extremely lean subjects or drastic caloric deficits), and that data have shown that hormonal and energetic adaptations can be notably moderated by implementing the aforementioned recommendations (Trexler