title: Effects of hydraulic resistance circuit training on physical fitness components of potential relevance to +Gz tolerance.
abstract: Recent studies carried out in the United States and Sweden have demonstrated that strength training can improve +Gz acceleration tolerance. Based on these findings, the Canadian Forces have introduced a training program for aircrew of high performance aircraft. This report describes the changes in physical fitness components considered relevant to +Gz tolerance after 12 weeks of training with this program. Prior to beginning training, 45 military personnel were tested, but only 20 completed a minimum of 24 training sessions. The following variables were measured in these 20 subjects before and after training: maximal strength of several large muscle groups during isokinetic contractions, maximal aerobic power and an endurance fitness index, maximal anaerobic power, anthropometric characteristics, and maximal expiratory pressure generated during exhalation. Training involved hydraulic resistance circuit training 2-4 times/week. The circuit consisted of 3 consecutive sets at each of 8 stations using Hydra-Gym equipment. The exercise:rest ratio was 20:40 s for the initial 4 training weeks and was then changed to 30:50. After training the changes in anthropometric measurements suggested that lean body mass was increased. Small, but significant, increases were also measured in muscle strength during bench press, biceps curls, squats, knee extension, and knee flexion. Neither maximal anaerobic power (i.e. muscular endurance) nor maximal expiratory pressure were changed after the training. Indices of endurance fitness were also increased in the present study. The relatively small increases in strength are probably due to the design of the exercise:rest ratio which resulted in improved strength and aerobic fitness.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000328:Adult; D000332:Aerobiosis; D000693:Anaerobiosis; D000886:Anthropometry; D005260:Female; D006112:Gravitation; D006801:Humans; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008297:Male; D009132:Muscles / Q000502:physiology; D010101:Oxygen Consumption; D010806:Physical Education and Training; D010809:Physical Fitness
chemical_list: D007773:Lactates; D019344:Lactic Acid