High-intensity progressive resistance strength training for older adults improves leg strength, but training volume also has an important effect

Raymond MJ, Bramley-Tzerefos RE, Jeffs KJ, et al. Systematic review of high-intensity progressive resistance strength training of the lower limb compared with other intensities of strength training in older adults Arch Phys Med Rehabil. 2013;94:1458-72.

Review question

What is the effect of high-intensity progressive resistance strength training of the legs for older adults? This type of training was defined as performing a resistance exercise (such as weight training) that is 70% to 89% of the maximum resistance the individual can bear for a single repetition of the exercise.

Background

Exercise has been shown to limit functional decline in older people, and improve overall quality of life. Progressive resistance strength training (PRST) is a commonly employed training method. What intensity of training is required for the greatest benefit is still unclear.

How the review was done

This is a summary of a systematic review of 21 randomized controlled trials published between 1995 and 2007. The studies included 830 participants who were 60 years of age and older. The average age was 65. Participants had no prior PRST experience.

Training involved the use of resistance machines for leg exercise. High-intensity PRST was compared against PRST at lower intensities.

Training session length ranged from 45 to 90 minutes. Program duration ranged from 8 to 52 weeks, with participants attending 2 to 3 sessions per week.

What the researchers found

Leg strength

• High-intensity PRST led to improvements in leg strength. Similar gains in leg strength were also observed when the intensity was lower but number of repetitions was higher (e.g. less weight but more repetitions).

Flexibility

• High- and moderate- intensity PRST led to increased flexibility compared to low-intensity programs.

Functional performance

• PRST of any intensity led to improvements in walking speed, functional performance, and disability.

Program duration

• There was no clear relationship between program duration and outcome, which implies that longer programs are not required to achieve additional benefits.

Adverse events

• Most studies did not report details on adverse events. Where injuries were reported, rates of injury were similar among high-, moderate-, and low-intensity training.

Study quality

• Most of the studies were considered to be of fair or moderate methodological quality.

Conclusion

PRST leads to improvements in leg strength and functional status, whereas high and moderate intensity PRST leads to increased flexibility.