Load-power relationship in older adults: The influence of maximal mean and peak power values and their associations with lower and upper-limb functional capacity

Identifying the relative loads (%1RM) that maximize power output (P(max-load)) in resistance exercises can help design interventions to optimize muscle power in older adults. Moreover, examining the maximal mean power (MP(max)) and peak power (PP(max)) values (Watts) would allow an understanding of their differences and associations with functionality markers in older adults. Therefore, this research aimed to 1) analyze the load-mean and peak power relationships in the leg press and chest press in older adults, 2) examine the differences between mean P(max-load) (MP(max-load)) and peak P(max-load) (PP(max-load)) within resistance exercises, 3) identify the differences between resistance exercises in MP(max-load) and PP(max-load), and 4) explore the associations between MP(max) and PP(max) in the leg press and chest press with functional capacity indicators. Thirty-two older adults (79.3 ± 7.3 years) performed the following tests: medicine ball throw (MBT), five-repetition sit-to-stand (STS), 10-m walking (10 W), and a progressive loading test in the leg press and chest press. Quadratic regressions analyzed 1) the load-mean and peak power relationships and identified the MP(max-load), MP(max), PP(max-load), and PP(max) in both exercises, 2) the associations between MP(max) and PP(max) in the chest press with MBT, and 3) the associations between MP(max) and PP(max) in the leg press with STS(power) and 10W(velocity). In the leg press, the MP(max-load) was ∼66% 1RM, and the PP(max-load) was ∼62% 1RM, both for women and men (p > 0.05). In the chest press, the MP(max-load) was ∼62% 1RM, and the PP(max-load) was ∼56% 1RM, both for women and men (p > 0.05). There were differences between MP(max-load) and PP(max-load) within exercises (p < 0.01) and differences between exercises in MP(max-load) and PP(max-load) (p < 0.01). The MP(max) and PP(max) in the chest press explained ∼48% and ∼52% of the MBT-1 kg and MBT-3 kg variance, respectively. In the leg press, the MP(max) and PP(max) explained ∼59% of STS(power) variance; however, both variables could not explain the 10W(velocity) performance (r ( 2 ) ∼ 0.02). This study shows that the P(max-load) is similar between sexes, is resistance exercise-specific, and varies within exercises depending on the mechanical power variable used in older adults. Furthermore, this research demonstrates the influence of the MBT as an upper-limb power marker in older adults.