Concurrent muscle hurt and perceived exertion of children during resistance exercise

Rating of muscle hurt (RMH) and RPE were concurrently measured for 10- to 14-yr-old females (n = 50) and males (n = 50) performing unilateral biceps curl (BC) and knee extension (KE) isotonic exercise.

BC and KE exercises were counterbalanced within subjects. Three counterbalanced, 10 repetition sets (30%, 50%, and 70% one repetition maximum (1-RM)) were performed for both exercises. RMH and RPE were obtained for active muscles using the Children's OMNI-Hurt Scale and the Children's OMNI-Resistance Exercise Scale of Perceived Exertion, respectively.

For both females and males, RMH ranged across sets from 1.5 to 6.0 during BC and 3.2 to 6.7 during KE. RPE ranged from 3.4 to 8.3 during BC and 5.0 to 8.9 during KE. Ratings expressed as percent scores were lower (P < 0.01) for RMH than for RPE at the 30%, 50%, and 70% 1-RM during BC and KE for females and males. Regression coefficients for weight lifted as a function of RMH ranged from r = 0.67 to r = 0.87 (P < 0.01) for BC and KE. Correlations between RMH and RPE ranged from r = 0.19 to r = 0.82 across sets for both genders.

Female and male children can concurrently and differentially rate their perceived intensity of muscle hurt and exertion during upper and lower body resistance exercise using numerical category metrics (i.e., OMNI scales) having construct-specific pictorial and verbal descriptors.