Abstract

150 (75 female and 75 male) competitive crawl swimmers, were studied from the point of view of their best performance in 400 m freestyle in competition (V 400). The maximal oxygen uptake (V02 max) was measured during a continuous front crawl swimming session at progressively increasing speed until exhaustion. Their passive drag (R 140) was measured, the swimmers being dragged passively at 1.4 m/s in a prone position. The duration of training (Tr) was measured in hour per week and some anthropometric data as follows: body area (BA) from the height and the weight, arm length (AL) from the acromion to the end of the third finger. The hydrostatic lift (HL) was measured after a maximal inspiration. The performance V 400 can be summarised by the equation (1) V 400 = V02 max + TR - R 140 + LA + HL + constant. All the variables are significant. The variables coefficients respectively 0.11, 0.009, 0.056, 0.006, 0.03 and 0.7 are significant except for hydrostatic lift. The relative influence on time performance was calculated by changing each variable of equation (1) by one S.D.. The aforementionned variables account for 16, 11, 8, 6 and 4 seconds in the 4 min 30 s mean performance of the studied population. The body drag is function of body area and training duration. Equation (2) R 140 = 27.4 BA -03 Tr + 0.24. Equation (1) allows to postulate that the best mean velocities over 400 m are sustained by swimmers characterised by a high aerobic capacity, a long training duration, long arms and high buoyancy. Body drag even measured in a passive way appears to be a very effective yet simple technique to measure the swimmers hydrodynamic characteristics. Verf.-Referat