Weight trainers in their seventies can derive more benefit from their workouts by making their concentric movements more explosive. This is the result of a study that sports scientists at Wake Forest University have published in Health and Quality of Life Outcomes.
Strength training makes elderly people stronger and more muscular. Nothing new here. What's less clear is the extent to which older people benefit from their newfound strength in daily life. According to recent reviews, which summarise the few (and at times contradictory) studies available, the only benefit of strength training is that it helps with simple movements that require strength. [Phys Ther. 2010 Dec;90(12):1711-5.]
In 2003 researchers discovered that people in their seventies react better to strength training if they make the movement with which they lift the weights up – the concentric movement – more explosive. [J Gerontol A Biol Sci Med Sci. 2003 Feb; 58(2): 171-5] "Power training" is what the researchers called this form of strength training.
Inspired by this study, the researchers at Wake Forest University did an experiment with three groups, each consisting of 15 people over seventy, lasting 12 weeks. The control group did nothing throughout the same period.
The strength-training group went to a gym three times a week and worked through a standard training programme. The subjects trained at 70 percent of their 1 RM. The subjects were asked to take 2-3 seconds for both the concentric and eccentric movements.
The power-training group did almost the same as the strength-training group. The only difference was that the subjects were asked to perform the concentric movement as fast as possible.
Before and after the 12-week training period the researchers asked the subjects to complete a questionnaire. They had to indicate how many kgs they could lift in the gym [Self-efficacy for Strength], whether their body was strong enough to perform everyday tasks [Satisfaction with Physical Function] and how content they were with life in general [Life Satisfaction].
Power training and strength training both had an equal effect on satisfaction with life in general, and on the strength the subjects developed in the gym. But the power training helped the subjects to perform better in daily life, and did so more than the regular strength training.
"Although both traditional strength training and high velocity power training enhance self-efficacy, power training may offer older adults unique benefits to multiple levels of quality of life beyond the influence of traditional strength training", the researchers conclude. "Clinically, power training may be a particularly beneficial mode of training for older adults at risk for mobility disability or other strength/muscle related disorders and lead to enhanced quality of life."
Health Qual Life Outcomes. 2008 Jun 13;6:45.