Hormonal responses to high- and moderate-intensity strength exercise

Abstract

The hormonal responses of nine male, strength athletes to strength exercise were examined. The athletes performed one moderate- and one high-intensity strength exercise workout. In the high-intensity workout, the load was 100% of each subject's three-repetition maximum (3-RM) for squats and front squats, and 100% of each subject's six-repetition maximum (6-RM) for leg extensions. In the moderate-intensity workout, the load was 70% of the high-intensity protocol. Rest periods between sets were 4-6 min for both workouts. Blood samples were taken before, 30 min into, and every 15 min for the 1st h after exercise, and then 3, 7, 11, 22 and 33 h after exercise, thus allowing examination of both the acute and prolonged hormonal responses. Blood samples were analyzed for testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), cortisol, adrenocorticotrophic hormone (ACTH), growth hormone (GH), insulin-like growth factor (IGF-1), insulin, sex hormone binding globulin, creatine kinase, total protein, glucose and lactate. The acute responses of testosterone and cortisol were greater during the high-intensity protocol as compared to the moderate-intensity protocol. The cortisol response was associated with an increase in ACTH concentration. LH and FSH showed no response to either protocol. Acute GH responses were not different between protocols. There were great inter-individual differences in acute GH responses to both protocols. There were no significant differences between protocols with regard to prolonged responses for any hormone. In both trials, IGF-1 concentrations were significantly lower at 0800 hours the morning after exercise as compared to concentrations found at 0800 hours the morning before exercise. The mechanisms responsible for reducing IGF-1 concentration in these trials are unclear, and it is not known if this reduction observed 22 hours after exercise is of physiological significance.

Physiological elevation of endogenous hormones results in superior strength training adaptation

“…Kraemer et al 1990;Häkkinen and Pakarinen 1993;Gotshalk et al 1997;Raastad et al 2000;Ratamess et al 2005). Furthermore, the finding of no change in hormonal levels during the A training, which included low muscle mass and low training volume, is also in line with previous findings (Häkkinen and Pakarinen 1993;Gotshalk et al 1997;Ratamess et al 2005).…”

“…In the L+A sessions, the general warm-up was followed by two warm-up sets in leg press with gradually increasing load. The leg exercise protocol was based on prior studies showing that involvement of a large muscle mass, high in volume, moderate to high in intensity, using short rest intervals; tend to produce the greatest acute hormonal elevations (Raastad et al 2000;Smilios et al 2003;Kraemer and Ratamess 2005). Leg exercises performed were:…”

Anaerobic endurance of young untrained male and female subjects

“…Many authors reported studies on repeated maximal exercises [1][2][3][4][5][6][9][10][11][12] consisting of 3 to 10 bouts separated by intermissions of constant or variable duration but offered no global assessment of a series of exercise bouts. The aim of this study was to assess the anaerobic endurance of untrained male and female subjects by applying the so-called performance index to repeated maximal exercises.…”

Respostas hormonais agudas a diferentes intensidades de exercícios resistidos em mulheres idosas

“…O TR, atividade voltada para o desenvolvimento das funções musculares através da aplicação de sobrecargas, é uma intervenção capaz de promover expressivos aumentos de força e massa muscular em idosos (7) . Os exercícios resistidos induzem respostas fisiológicas agudas importantes para ganhos de força e hipertrofia muscular; alterações hormonais que promovam um "ambiente" anabólico apresentam papel importante nas adaptações crônicas induzidas pelo treinamento (8) . Por outro lado, em indivíduos com idade avançada, essas respostas precisam ser mais bem caracterizadas.…”

“…O cortisol, principal glicocorticóide secretado pela ativação do eixo hipotálamo-hipófise-adrenal, apresenta função catabólica e parece sofrer elevação transitória após uma sessão de exercícios resistidos (11) . Em adendo, tem sido sugerido que a razão testosterona/cortisol (RTC) seja um indicador do status anabólico/catabólico do músculo esquelético durante o TR (12) e as respostas aos exercícios resistidos são dependentes, dentre outros fatores, da intensidade realizada (8) . O hormônio do crescimento (GH), secretado pela hipófise anterior, apresenta papel relevante na síntese protéica e por isso tem sido foco de estudos que versam sobre as respostas agudas aos exercícios resistidos (13)(14) .…”