Effects of free weights and machine training on muscular strength in high-functioning older adults

Background: Resistance training is assumed to be a key player in counteracting the age-related decline of functional capacity as well as the incidence of falls in older adults. Functional training using free weights is presumed to mimic daily activities, but there is a lack of studies comparing free weight training with barbells and machine training in older adults. The purpose of this study was to evaluate the development of muscle strength for high resistance training in high functioning older people for machines as well as free-weights as well as testing the feasibility of free weight training for this target group. Methods: Thirty-two fitness trained women and men aged 60 to 86 years (mean: 66.9, SD: +/- 5.5) participated in this study. Machine exercisers (n = 16; chest press, leg press, upper row, biceps cable curls, triceps cable extension) vs. free weight exercisers (n = 16; squat, bench press, bent-over rowing, biceps curls, lying triceps press) participated twice a week for a total of 26 weeks. They trained the same five muscle groups for three sets with 10 to 12 repetitions at the 10-Repetition-Maximum, followed by 20 min of endurance training over six months. Three measurements (dynamic, isometric strength and endurance) were taken at the beginning, after 10 weeks and again after 26 weeks. Results: Repeated measures MANCOVA analysis revealed significant increases in the free weights training group (FWT) as well as in the machine training group (MT) over the period of 6 months. However, only for leg strength (113 vs. 44%) and triceps (89.0 vs. 28.3%) the free-weights group exhibited significant differences for the percentage increase over a period of 26 weeks compared to the machine group. A detraining period revealed the decline of the dynamic strength without training. The analysis of the follow-up questionnaire resulted in higher demands for safety, but also higher values for fun, motivation, future, and benefit for daily life for the FWT group compared to the MT group indicating an overall better evaluation of their training specific regime. Conclusion: Our results demonstrate that especially free-weight training has benefits in improving leg and triceps strength as well as in the subjective perception in older adults. Nevertheless, our results do not overall indicate that free-weight training is superior to machine training for increasing strength.