The pull-up (PU) test is widely used to assess body mass-relative dynamic muscular endurance. Although fat is a major compartment of body mass, the source of resistance for the PU, little is known of the effect of fat mass on PU. This investigation examined the effect of simulated fat mass on the PU performance in 30 fit young men. Allometric scaling (AS) was used to model the relationship between total mass lifted (KGT) and PU, and KGT was manipulated by adding known mass to each subject and having him do as many PUs as possible. AS was used to determine the value of the exponent a for each subject. The mean and standard deviation of the a values of all subjects was -7.91 +/- 2.3. This meant, for example, that a 10% increase in KGT (the increase due to fat mass alone) would lead to a 53% decrease in PU. Given previous data suggesting that the PU test may substantially penalize those with larger FFM, it appears that this test may be too unduly influenced by body size and fatness to adequately measure mass-relative dynamic muscular endurance in fit young men.
(C) 1997 National Strength and Conditioning Association