Acute High Intensity Anaerobic Training and Rhabdomyolysis Risk

International Journal of Exercise Science 8(1) : 65-74, 2015. The current popularity of high intensity anaerobic training has caused concerns over the safety and prevalence of conditions such as rhabdomyolysis; thus it is important to understand the possible risks of participating in this type of activity. The purpose of this study was to determine the magnitude of muscle damage associated with a single high intensity anaerobic training session, and the relationship of this response to markers of fitness. Fifteen recreationally trained male participants (age 22.9 ± 4.3 y, mass 87.3 ± 15.6 kg, body fat 16.8 ± 6.4%, VO2 peak 50.1 ± 7.2 ml · kg-1 · min-1 ) completed a single anaerobic training session consisting of high intensity plyometrics and calisthenics. Prior to the exercise session, participants completed a maximal aerobic capacity test, body composition analysis, and a military physical fitness test (1 min push-ups, 54 ± 14; 1 min sit-ups, 45 ± 11; 1.5 mile run, 12:17 ± 0.067 min). Serum creatine kinase (CK) was measured prior to and 48 h following the exercise session. CK at 48 h (126.3 ± 68.9 U· L-1) did not reach the limits indicating rhabdomyolysis (~881-1479 U/L) but was elevated above resting (CK resting 90.5 ± 53.4). VO2 peak (L · m-1) had a positive correlation with CK levels (r = .51; p \u3c 0.05) but body mass or any other indicator of fitness did not correlate. An increase in serum CK levels occurred, but did not reach levels of rhabdomyolysis, suggesting that a single high intensity exercise session is safe for healthy individuals who exercise regularly

Proteolytic Gene Response to Exercise and Temperature

Aging is characterized by a relative maintenance of myogenic activity and increased proteolytic activity resulting in a loss of muscle mass termed sarcopenia. Little is known about the impact of muscle temperature on the regulation of proteolysis associated with sarcopenia. The purpose of this study is to determine the impact of local muscle heating and cooling on proteolytic gene response following resistance exercise. Recreationally resistance trained male participants will complete 4 sets of 8-12 repetitions of leg extension and leg press at 80% of their 1-repetition maximum for each exercise with two minutes recovery between sets. A ThermaZone Continuous Thermal Therapy System will be used to heat the upper thigh of one leg and cool the upper thigh of the other leg. A muscle biopsy will be taken on one leg (randomized) pre exercise and both legs 4 hours post exercise while femoral blood flow will be measured on both legs pre, post, and 4 hours post exercise. Gene expression analysis will be done on the proteolytic genes of interest Atrogin 1, MuRF1, and FOXO3A. This study will provide critical information for the development of novel temperature optimized exercise strategies that may help combat sarcopenia

Proteolytic Gene Response to Exercise and Temperature

Aging is characterized by a relative maintenance of myogenic activity and increased proteolytic activity resulting in a loss of muscle mass termed sarcopenia. The purpose of this study is to determine the impact of local muscle heating and cooling on proteolytic gene response following resistance exercise. Recreationally resistance trained male participants (25.3 ± 5.0 y, 178.7 ± 6.1 cm, 86.8 ± 12.5 kg, 13.6 ± 6.6 % body fat, 1 RM Leg Press 139.0 ± 18.9 kg, 1 RM Leg Extension 67.2 ± 10.5 kg). The participants completed 4 sets of 8-12 repetitions of leg extension (LE) and leg press (LP) with each leg. Participants accomplished an average of 11 ± 1 reps at 76.6 ± 4.5% of 1 RM for LE and 9 ± 1 reps at 61.1 ± 6.5% of 1 RM for LP. ThermaZone Continuous Thermal Therapy System was used to heat the upper thigh of one leg and cool the upper thigh of the other leg. A muscle biopsy was taken from each leg pre- and 4 h post-exercise. Gene expression analysis will be done on the proteolytic genes of interest Atrogin 1, MuRF1, and FOXO3A. The mRNA analysis is nearing completion and will be finished for presentation at the research fair. This study will provide critical information for the development of novel temperature optimized exercise strategies that may help combat sarcopenia