Doctor of Philosophy (PhD)
The primary purpose of this dissertation was to investigate the acute effect of different REs on the heart, the effect of conventional RE on the heart in combination with nutraceuticals, through measuring rate pressure product (RPP). Three studies were conducted in this dissertation.
The first study was to examine the effect of volume-matched single-set and multiple-set leg press exercise on myocardial energy expenditure. Fourteen healthy untrained college students performed 4 sets of 10 repetitions or 40 repetitions of leg press exercise at 150% body weight on different days. Post-exercise RPP, RPPdiff, RPPperc, and HRperc for single-set were significantly greater than that of multiple-set RE. These results imply single-set RE exerts a greater stress on the heart. Thus, single-set and multiple-set RE can be prescribed to different populations with varied training goals.
The second study was to investigate the effect of Muscle Sentry® on improving work performance and cardiovascular efficiency. Twenty-one college students performed 3 sets to failure chest and leg pressure exercises at 8 RM with 2 min rest between sets. No treatment effect was found on total work performed and estimated MVO2 between treatments. These results show Muscle Sentry® intake 40 min prior to doing RE had no effect upon either total lift numbers or estimated MVO2, and suggests that the benefits of Muscle Sentry® are less than those claimed by the manufacturer.
The final study was to investigate the acute effect of N-acetylcysteine (NAC) on cardiovascular responses to regular RE. Nine recreationally strength trained college students finished this study, NAC or placebo, at a dosage of 1800 mg, was administrated one hour prior to perform 6 regular REs with 3 sets of 10 repetitions at 80% 1RM, 2 min rest between sets and exercises. No significant difference of post-exercise RPP between both treatments, post-exercise RPP of regular RE was significant greater than that of 1RM test. Increased HR was significant greater in regular RE than that of 1RM test. These results suggest NAC does not reduce post-exercise RPP in a conventional RE training program, HR not SBP plays a vital role in increasing heart stress during conventional RE.
Xu, Junhai, "Nutraceuticals & Resistance Exercise Training:Effects on Rate Pressure Product--- An Index of Myocardial Oxygen Consumption" (2020). LSU Doctoral Dissertations. 5405.
Nelson, Arnold G.