Effect of a 12-week mixed power training on physical function in dynapenic-obese older men: does severity of dynapenia matter?

Mobility disability affects nearly 15% of people aged 65 or over worldwide. Excess weight or obesity (OB), along with an accentuated loss of muscle strength (dynapenia), is recognized to be one of the most common risk factors for mobility impairment among the elderly. To investigate the effect of a 12-week mixed power training (MPT high-velocity resistance training mixed with functional exercises) on physical function in obese older men exhibiting different severities of dynapenia. Community-dwelling older men (69 +/- 6 years) were assigned to the study if they were considered obese (OB, fat mass >= 25% body weight, BW) and to one of the two groups according to severity of dynapenia [(handgrip strength-HS)/BW]: type 1(OB-DY1) or type 2(OB-DY2), < 1 or 2SD from a young reference group. Participants followed a 12-week MPT, three times/week, 75 min/session. Main outcomes included the performance on the 4-m and 6-min walking tests, Timed Up and Go, stair and balance tests. At baseline, OB-DY1 performed better than OB-DY2 in all functional tests (p < 0.05). Following the intervention, medium-to-large training effect size (ES) were observed for fat (ES = 0.21) and lean (ES = 0.32, p < 0.001) masses, functional performance (ES 0.11-0.54, p < 0.05), HS (ES = 0.10, p < 0.05) and lower limb muscle strength (ES = 0.67, p < 0.001) and power (ES = 0.60, p < 0.05). Training-by-group interaction showed that OB-DY1 lost more FM (ES = 0.11, p = 0.03) and OB-DY2 improved more HS (ES = 0.19, p = 0.006) than their counterparts. Seniors with obesity and severe dynapenia have poorer physical function than those in the early stage of dynapenia. Both seem to benefit from a high-velocity resistance training mixed with functional exercises, although by slightly different pathways.