Resistance Exercise Dosage in Men with Prostate Cancer: Systematic Review, Meta-analysis, and Meta-regression

Abstract

Purpose: Resistance exercise improves an array of treatment-related adverse effects in men with prostate cancer; however, the minimal dosage required is unknown. We systematically reviewed the resistance training 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, and prostate-specific antigen.

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

Results: Twenty-three articles describing 21 trials and involving 1748 prostate cancer patients were included. Exercise improved fat mass (-1% in body fat and -0.6 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., V̇O2peak and muscle strength) (P = 0.040-<0.001) with no change in body mass index or prostate-specific antigen (P = 0.440-0.735). Meta-regression indicated no association between exercise type, resistance training duration, weekly volume and intensity, and primary outcomes (P = 0.075-0.965). There was a significant association between exercise intensity and chest press muscle strength (favoring moderate intensity, P = 0.012), 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 resistance training for enhancing body composition, functional capacity, and muscle strength in the short term. A low exercise dosage may help reduce barriers to exercise and enhance adherence.

FIGURE 1

Flow chart of study selection process. *Primary outcome.

FIGURE 2

Mean difference effects of resistance-based exercise compared with control on percentage body fat (A), fat mass (B), and trunk fat mass (C). Overall and subgroup analyses conducted with a random-effects model. Gray and white circles represent study-specific estimates based on risk of bias assessment (low risk and some concern or high risk of bias, respectively); I² represents the heterogeneity test; diamonds represent pooled estimates of random-effect meta-analysis. *Combined resistance and aerobic group. #Resistance training plus impact-loading group.

FIGURE 3

Mean difference effects of resistance-based exercise compared with control on lean mass (A) and appendicular lean mass (B). Overall and subgroup analyses conducted with a random-effects model. Gray and white circles represent study-specific estimates based on risk of bias assessment (low risk and some concern or high risk of bias, respectively); I² represents the heterogeneity test; diamonds represent pooled estimates of random-effect meta-analysis. *Combined resistance and aerobic group. #Resistance training plus impact-loading group.

FIGURE 4

Mean difference effects of resistance-based exercise compared with control on 30-s sit-to-stand repetitions (A), 5 sit-to-stand test (B), 400-m walk test (C), 6-m usual walk test (D), 6-m fast walk test (E), timed up-and-go test (F), and stair climb test (G). Overall and subgroup analyses conducted with a random-effects model. Gray and white circles represent study-specific estimates based on risk of bias assessment (low risk and some concern or high risk of bias, respectively); I² represents the heterogeneity test; diamonds represent pooled estimates of random-effect meta-analysis. *Combined resistance and aerobic group. #Resistance training plus impact-loading group. 30SS, 30-s sit-to-stand test; TUG, timed up-and-go test.

FIGURE 5

Mean difference effects of resistance-based exercise compared with control on chest press (A), leg press (B), leg extension (C), and seated row (D). Overall and subgroup analyses conducted with a random-effects model. Gray and white circles represent study-specific estimates based on risk of bias assessment (low risk and some concern or high risk of bias, respectively); I² represents the heterogeneity test; diamonds represent pooled estimates of random-effect meta-analysis. *Combined resistance and aerobic group. #Resistance training plus impact-loading group.

FIGURE 6

Mean difference effects of resistance-based exercise compared with control on V̇O_2peak (A), BMI (B), and PSA levels (C). Overall and subgroup analyses conducted with a random-effects model. Gray and white circles represent study-specific estimates based on risk of bias assessment (low risk and some concern or high risk of bias, respectively); I² represents the heterogeneity test; diamonds represent pooled estimates of random-effect meta-analysis.