The purpose of this investigation was to examine the acute hormonal response to a bout of kettlebell swing exercise. Ten healthy men (19-30 y, 23.6 ± 3.5 y, 174.6 ± 5.7 cm, 78.7 ± 9.9 kg) who were engaged in resistance training at least twice per week but were inexperienced with kettlebell swings participated in this study. Participants were familiarized with the kettlebell swing exercise during an initial visit. During the subsequent experimental protocol visit, participants performed 12 rounds of 30 seconds of 16-kg kettlebell swings alternated with 30 seconds of rest. Heart rate (HR) and rating of perceived exertion (RPE) were measured at the end of every round of swings. Fasted blood samples were collected pre-exercise (PRE), immediately post (IP), 15 minutes post (P15), and 30 minutes post exercise (P30) and analyzed for total testosterone (T), growth hormone (GH), cortisol, and lactate concentrations. Participants completed a total of 227 ± 23 swings (average swings per round: 19 ± 2). HR and RPE increased significantly (P < 0.05) throughout the exercise protocol. Lactate concentrations were significantly increased at all post exercise time points compared to PRE. T was significantly increased at IP compared to PRE. GH was significantly increased at IP, P15, and P30 compared to PRE. Cortisol was significantly increased at IP and P15 compared to PRE. 12 rounds of 30 seconds of kettlebell swing exercise induced an acute increase in T, GH, and cortisol concentrations in resistance trained men. Additionally, this exercise protocol induced a large increase in HR and lactate concentration. Thus, the kettlebell swing exercise might provide an effective method for simultaneous endurance and resistance training.

Puberty is a critical period of development that is characterized by significant remodeling and reorganization of neuronal connections. Additionally, this period is marked by the transition to a fertile state and the development of secondary sex characteristics driven by a surge in gonadal steroid hormones. Puberty is also vulnerable to stress exposure, as pubertal stress during this period results in negative enduring changes to the brain and behavior. Treatment with the bacterial endotoxin lipopolysaccharide (LPS) results in enduring dysfunction of the hypothalamic-pituitary-gonadal (HPG) axis in male and female mice. However, the mechanism underlying this dysfunction was unclear. Thus, this thesis was designed to investigate possible mechanisms through which pubertal stress could alter HPG axis functioning. This work first examined the acute effects of LPS treatment on various components of the HPG axis, such as kisspeptin (Kiss1) and kisspeptin receptor (Kiss1R) expressions in the brain, and luteinizing (LH) and follicle stimulating hormone (FSH) concentrations in the blood (Study 1). The next study examined the enduring effects of LPS treatment on inflammation as well as on Kiss1 and Kiss1R expressions in the brain, and LH and FSH concentrations in the blood (Study 2). The findings showed that Kiss1 and Kiss1R were downregulated in an acute and enduring manner following LPS treatment and are likely responsible for HPG axis downregulation. The final study amalgamates the novel discoveries of the previous findings and hypothesizes that pharmaceutical Kiss1 treatment will prevent adult sexual behavior dysfunction after pubertal LPS treatment. Findings from this study will inform us whether the enduring HPG axis downregulation following pubertal LPS treatment is reversible in adulthood and could provide a viable prospective intervention for fertility complications across species.

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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.