Physiological elevation of endogenous hormones results in superior strength training adaptation

Abstract

This file was dowloaded from the institutional repository Brage NIH -brage.bibsys.no/nih Rønnestad, B. R., Nygaard, H., Raastad, T. (2011) ABSTRACTThe purpose of this study was to determine the influence of transiently elevated endogenous hormone concentrations during exercise on strength training adaptations. Nine subjects performed four unilateral strength training session per week on the elbow flexors for 11 weeks. During two of the weekly sessions, leg exercises were performed to acutely increase the systemic anabolic hormone concentration immediately before the exercises for one of the elbow flexors (L+A). On the two other weekly training sessions, the contralateral elbow flexors were trained without prior leg exercises (A). By randomizing one arm of the subjects to serve as a control and the other as experimental, both conditions have the same nutritional and genetic environment. Serum testosterone and growth hormone was significantly increased during the L+A training session, while no hormonal changes occurred in the A session. Both A and L+A increased 1RM in biceps curl, peak power in elbow flexors at 30% and 60% of 1RM, and muscle volume of the elbow flexors (p<0.05). However, only L+A achieved increase in CSA at the part of the arm flexors with largest cross sectional area (p<0.001), while no changes occurred in A. L+A had superior relative improvement in 1RM biceps curl and favorable muscle adaptations in elbow flexors compared to A (p<0.05). In conclusion, performing leg exercises prior to arm exercises, and thereby increasing the levels of serum testosterone and growth hormone, induced superior strength training adaptations compared to arm training without acute elevation of hormones.

The Acute Hormonal Response to the Kettlebell Swing Exercise

“…Consistent with previous findings for resistance exercise, serum T concentrations were significantly increased immediately following the kettlebell exercise bout. The magnitude of post exercise increase in T concentrations was similar to that found in some previous studies on free weight resistance exercise (Hansen et al, 2001;Linnamo et al, 2005;Ronnestad et al, 2011); however, the duration of the increase was shorter than found in some studies (Hansen et al, 2001;Kraemer et al, 1998). The cause of this shorter duration for the elevation in testosterone concentration is not known, but could be due, at least in part, to plasma volume shift.…”

“…The neuromuscular adaptations to resistance training are modulated by the endocrine milieu and acute hormonal response to each exercise bout (Hansen, Kvorning, Kjaer, & Sjogaard, 2001;Kvorning, Andersen, Brixen, & Madsen, 2006;Ronnestad, Nygaard, & Raastad, 2011). Concentrations of circulating of testosterone, growth hormone, cortisol, and other hormones are increased in response to an acute bout of heavy resistance exercise (Kraemer, Noble, Clark, & Culver, 1987;Kraemer et al, 1998;Linnamo, Pakarinen, Komi, Kraemer, & Hakkinen, 2005;Smilios, Pilianidis, Karamouzis, & Tokmakidis, 2003).…”

“…Concentrations of circulating of testosterone, growth hormone, cortisol, and other hormones are increased in response to an acute bout of heavy resistance exercise (Kraemer, Noble, Clark, & Culver, 1987;Kraemer et al, 1998;Linnamo, Pakarinen, Komi, Kraemer, & Hakkinen, 2005;Smilios, Pilianidis, Karamouzis, & Tokmakidis, 2003). A greater hormonal response to resistance exercise sessions may lead to greater physiological adaptations, such increases in strength (Hansen et al, 2001;Ronnestad et al, 2011). Acute administration of testosterone increases protein synthesis in young, pre-pubertal boys (Mauras et al, 1994) and supraphysiologic doses of testosterone improve muscle size and strength in healthy men, especially when combined with strength training (Bhasin et al, 1996).…”

Irisin and FNDC5: effects of 12-week strength training, and relations to muscle phenotype and body mass composition in untrained women

“…This was evident as a lack of effects on FNDC5 expression in both VL and BB and s-irisin. This may be due to a type II error, as even subtle changes in design of strength training protocols have previously been found to affect training-associated adaptations following upper body strength exercises (Rønnestad et al 2011). However, this study was performed on men, and its findings may not be relevant to women.…”

Evolving the neuroendocrine physiology of human and primate cooperation and collective action

“…While engaging in physical competition often results in acute increases in testosterone in both competitors, the winners of male-male competition appear to have larger increases in testosterone across many taxa [107], including many, though not all, studies in humans [39]; this phenomenon is often called the 'Winner Effect' or 'WinnerChallenge Effect'. In humans and animal models, repeated acute increases in testosterone during physical activity have the potential to benefit muscle physiology [104,105,110] (though see [111,112], and the rebuttal [113]). In animal models, repeated winning during conflict can result in more aggressive strategies and the increased probability of winning future fights [107,114].…”