Resistance Exercise Dosage in Men with Prostate Cancer

Purpose
Resistance training (RT) improves an array of treatment-related adverse effects in men with prostate cancer, however, the minimal dosage required is unknown. We systematically reviewed the RT effects in prostate cancer patients to determine the minimal dosage regarding the exercise components (type, duration, volume, and intensity) on body composition, physical function, muscle strength, cardiorespiratory fitness, body mass index (BMI), and prostate-specific antigen (PSA).

Methods
Using PRISMA guidelines, MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science databases were searched. Eligible randomised controlled trials examined prostate cancer patients undertaking resistance-based exercise programs during or following treatment. Meta-analysis was undertaken when more than 3 studies were included. Associations between mean differences and the exercise components were tested by univariate and multivariate meta-regression analysis.

Results
Twenty-four papers describing 22 trials and involving 1,888 prostate cancer patients were included. Exercise improved fat mass (-1% in body fat and -0.5 kg in fat mass), lean mass (+0.5 kg in lean and appendicular lean mass), functional capacity (i.e., chair rise, 400-m test, 6-m fast walk and stair climb tests) and fitness outcomes (i.e., VO2 peak and muscle strength) (P=0.040 – <0.001) with no change in BMI or PSA (P= .440 – .735). Meta-regression indicated no association between exercise type, RT duration, weekly volume and intensity and primary outcomes (P= .075 – .965). There was a significant association between RT intensity and chest press muscle strength (favouring moderate-intensity, P= .012), but not in other secondary outcomes.

Conclusion
In untrained older men with prostate cancer initiating an exercise program, lower volume at moderate-to-high intensity is as effective as higher volume RT for enhancing body composition, functional capacity and muscle strength in the short-term.