The authors conducted this study to investigate the effect of high-intensity progressive resistance strength training (HIPRST) on strength, function, mood, quality of life, and adverse events compared with other intensities in older adults. They conducted a search of online databases their inception to July 2012. Randomized controlled trials of HIPRST of the lower limb compared with other intensities of progressive resistance strength training (PRST) in older adults (mean age ≥65y) were identified. They included 21 trials. Study quality was fair to moderate (PEDro scale range, 3-7). Studies had small sample sizes (18-84), and participants were generally healthy. Meta-analyses revealed HIPRST improved lower-limb strength greater than moderate- and low-intensity PRST (standardized mean difference [SMD]=.79; 95% confidence interval [CI], .40 to 1.17 and SMD=.83; 95% CI, -.02 to 1.68, respectively). Studies where groups performed equivalent training volumes resulted in similar improvements in leg strength, regardless of training intensity. Similar improvements were found across intensities for functional performance and disability. They found little consistency in the effect of intense PRST on mood across all the studies . Adverse events were not well reported, however, no correlation was found between training intensity and severity of adverse events.
The investigation concluded that HIPRST improves lower-limb strength more than lesser training intensities, although it may not be necessary to improve functional performance. They also found training volume to be an important variable. They stated that HIPRST appeared to be a safe mode of exercise in older adults and added that additional research into its effects on older adults with chronic health conditions across the care continuum is required.