Cardiovascular and muscular adaptations to combined endurance and strength training in elderly women

Twenty-one women aged 60-75 years were examined to determine whether combined endurance and strength training resulted in greater increase in peak oxygen consumption, sub-maximal time to fatigue, cardiac output, stroke volume, and leg extension load when compared to endurance training alone. Subjects in both the endurance training (E) and endurance and strength (E & S) groups trained 3 days a week, for 12 weeks, at an intensity of 70-80% Vo2 peak for 30 min on a cycle ergometer. Subjects in the E & S groups also used resistance equipment to train the knee extensors. The workload for resistance training was based on an initial assessment of 10 repetitions maximum (10 RM), with 80% of that value used for training, three times weekly. Peak oxygen consumption increased to an average of 24.8 and 29.9% in the E and E & S groups, respectively, with no difference between groups. Subjects in the E & S and E groups significantly increased sub-maximal endurance time by 396 and 165%, respectively. Cardiac output, stroke volume, and arteriovenous oxygen difference at 80% peak VO2 were unchanged by either of the training methods. A needle biopsy was taken from the vastus lateralis before and after 12 weeks of training. Chi-square analysis of fibre area data showed an increase in the frequency of larger type I fibres in the post-training data from the E & S group, but an increase in the frequency of smaller fibres in the E group post-training; however, mean fibre area was not significantly changed by training. These data suggest that greater improvements in sub-maximal time to fatigue and strength is achieved when resistance training is added to an aerobic training programme in healthy elderly women.