A-15Q Free Communication/Poster Performance of Athletes
The total mechanical power output (PO) in freestyle swimming is utilized in overcoming drag (Pd, useful power) and giving masses of water a kinetic energy change (wasted power). Propelling efficiency (Ep) is the ratio of Pd to PO (Toussaint, 1994). Furthermore, peak aerobic power (PAP) has been proported to be an important predictor of performance outcome (i.e., distance running). Few studies, however, have examined the relationship of PAP and Ep to swimming performance.
To examine the relationship between propelling efficiency, peak aerobic power and freestyle swimming performance.
Trained collegiate male swimmers (n = 14) performed five submax. swims, a max swim to exhaustion, and a 365.8m (400 yd) freestyle performance swim. A snorkel apparatus was used during the swims to collect expiratory air (indirect calorimetry). Ep was estimated from the following description: Ep = Av3 eg−1 Pi−1, where, A = drag coefficient (A = 0.35 body wt. (kg) + 2; Toussaint,1988), v3 = swimming velocity cubed, Pi equals the metabolic power equivalent of oxygen uptake (Watts (W)), and eg = gross efficiency (constant, 9%; Toussaint, 1994).
(1) at a Pi of 1000W, Ep ranged from ∼30 to 63% (42.7 ± 2.9%); (2) the r value between the 386.4 m swim vs. Ep was 0.70 (p = 0.005); (3) mean PAP was 4.33 lO2 min−1 (3.73 to 4.84), (4) the r value between PAP vs Ep, and the 386.4 perform. swim was 0.30 and 0.17, respectively, (NS).
Peak aerobic power does not appear to be an important predictor of performance for a freestyle event (365.8 m) requiring a high aerobic energy contribution. Instead, the ability to effectively apply propulsive power (propelling efficiency) appears to be an important determinant of swimming success. The mean estimated Ep value of ∼ 43 % suggests that 57 % of total mechanical power output was wasted in giving masses of water a kinetic energy change and the balance used to overcome drag.