Benjamin H. Rogers, Justin C. Brown, David R. Gater, Kathryn H. Schmitz

To characterize the relationship between 1-RM bench press strength and isometric handgrip strength among BrCa survivors. Cross-sectional study. Laboratory. Community-dwelling BrCa survivors. Not applicable. 1-RM bench press strength was measured with a barbell and exercise bench. Isometric handgrip strength was measured using an isometric dynamometer with three maximal contractions of left and right hands. All measures were conducted by staff with training in clinical exercise testing. Among 295 BrCa survivors, 1-RM bench press strength was 18.2±6.1 kg (range: 2.2-43.0) and isometric handgrip strength was 23.5±5.8 kg (range: 9.0-43.0). The strongest correlate of 1-RM bench press strength was the average isometric handgrip strength of both hands (r=0.399; P<0.0001). Mean-difference analysis suggested that the average isometric handgrip strength of both hands overestimated 1-RM bench press strength by 4.7 kg (95% limits of agreement: -8.2 to 17.6). In a multivariable linear regression model, the average isometric handgrip strength of both hands (β=0.31; P<0.0001) and age (β=-0.20; P<0.0001) were positively correlated with 1-RM bench press strength (R(2)=0.23). Isometric handgrip strength is a poor surrogate for 1-RM bench press strength among BrCa survivors. 1-RM bench press and isometric handgrip strength quantify distinct components of muscular strength.