With global population ageing, sarcopenic obesity has become a common and serious condition in older adults. Exercise guidelines issued by the American College of Sports Medicine (ACSM) are authoritative in exercise science. For older adults with sarcopenic obesity, these guidelines provide multidimensional recommendations on exercise dose, including intensity, frequency, and duration for aerobic and resistance training.

To compare the effects of exercise doses with high adherence to ACSM recommendations versus those with low or uncertain adherence on body composition [body fat percentage, BMI, body weight, appendicular skeletal muscle mass (ASM) ] and physical function (grip strength and walking speed) in older adults with sarcopenic obesity.

Relevant studies on exercise interventions for older adults with sarcopenic obesity were systematically searched in PubMed, Embase, Web of Science, Cochrane Library, Ovid, and China National Knowledge Infrastructure (CNKI). The search period was from database inception to 2023-12-26 for the first four databases, and from database inception to 2024-01-14 for Ovid and CNKI. Two investigators independently screened the literature, extracted data, and assessed the risk of bias in the included studies. Study quality was evaluated using the risk-of-bias tool for randomized controlled trials, and Meta-analysis was performed using RevMan 5.4. Based on whether the intervention group's exercise dose adhered to ACSM recommendations, studies were classified as high adherence or low/uncertain adherence. The effects of these two exercise-dose categories on body fat percentage, BMI, body weight, ASM, grip strength, and walking speed were analyzed. Higgins I² was used to assess heterogeneity among studies, and sensitivity analysis was performed by omitting one study at a time.

A total of 15 studies involving 810 participants were included, of which 7 studies had high adherence to ACSM recommendations and 8 had low or uncertain adherence. Eleven studies reported body fat percentage as an outcome. Compared with the control group, the high-adherence intervention group showed a greater reduction in body fat percentage (MD=-3.54, 95%CI= -5.65 to -1.44, P<0.05), whereas the low/uncertain-adherence intervention group showed no statistically significant difference versus the control group (MD=-0.94, 95%CI=-2.54 to 0.67, P>0.05). Five studies reported BMI as an outcome. Compared with the control group, the high-adherence intervention group showed a greater reduction in BMI (MD=-1.98, 95%CI=-3.02 to -0.93, P<0.05). The low/uncertain-adherence intervention group also showed a reduction in BMI, but the difference was not statistically significant (MD=-1.72, 95%CI=-3.42 to -0.03, P=0.05). Five studies reported body weight as an outcome. Compared with the control group, the high-adherence intervention group showed a greater reduction in body weight (MD=-4.85, 95%CI=-7.84 to -1.86, P<0.05), while the low/uncertain-adherence intervention group showed no statistically significant difference versus the control group (MD=-1.56, 95%CI=-5.94 to 2.81, P>0.05). Four studies reported ASM as an outcome. For both high-adherence and low/uncertain-adherence exercise doses, no statistically significant differences were observed in ASM compared with the control group (MD=-0.18, 95%CI=-1.03 to 0.67; MD=-0.05, 95%CI=-0.85 to 0.76, P>0.05). Eight studies reported grip strength as an outcome. Compared with the control group, the high-adherence intervention group showed a greater increase in grip strength (MD=2.86, 95%CI=0.76 to 4.97, P<0.05), whereas the low/uncertain-adherence intervention group showed no statistically significant difference versus the control group (MD=3.04, 95%CI=-0.26 to 6.34, P>0.05). Seven studies reported walking speed as an outcome. The high-adherence intervention group improved walking speed more than the control group (MD=0.32, 95%CI=0.23 to 0.41, P<0.05), while the low/uncertain-adherence intervention group showed no statistically significant difference versus the control group (MD=0.05, 95%CI=-0.01 to 0.11, P>0.05).

High-adherence exercise interventions had significant effects on improving body fat percentage, BMI, body weight, grip strength, and walking speed in patients with sarcopenic obesity. However, exercise intervention had no effect on ASM. Further studies are needed to verify these findings.