INTRODUCTION There is considerable evidence of performance gains in 4 x 100 m freestyle relays over individual 100 m freestyle races (overview in Hüffmeier & Hertel, 2000). These gains consist of relay start benefits and increased swimmer effort due to the team situation. In this pilot study we want to analyze in which sections and in which way swimmers generally achieve a better performance in the relay race. We assume that swimmers increase their stroke rates in relays because this is a common strategy to swim faster in sprint events (Hay, 2002). METHODS Video footage (50 Hz) of N = 29 (12 female) swimmers from the European Junior Championships in Kazan (2019) was analyzed. Relay splits and individual races of each swimmer were analyzed for the race sections of clean swim: 15-25m, 25-35m, 35-45m, 65- 75m, 75-85m, and 85-95m. For each section, swim times were recorded, and swim cycles were counted. Stroke lengths and stroke rates were calculated from these parameters. Repeated measures ANOVAs were conducted to compare performance in the relay to the individual races for the dependent variables of swim time, stroke length, and stroke rates. RESULTS Results show faster mean swim times for the race sections in the relay (M = 5.65 s, SD = 0.10) compared to the individual race (M = 5.68 s, SD = 0.08), F(1, 27) = 9.51, p = .005, Etap2 = 0.26. Faster swim times were especially pronounced in the first three clean swim sections, eGG = 0.2, F(1, 27) = 252.85, p < .001, Etap2 = 0.90. Those faster swim times were achieved through higher stroke rates in those sections (15-25 m: +2.3%, 25-35 m: +4.1%, 35-45 m: +0.6%, 65-75 m: +0.2%, 75-85 m: -0.4%, 85-95 m: +0.5%), eGG = 0.2, F(1, 27) = 12.76, p < .001, Etap2 = 0.32. DISCUSSION This pilot study shows that performance gains in relay swimming were primarily achieved by increasing stroke rate in the first 50 m of the race. These results support the notion that relay swimmers do indeed swim faster, and that faster swim times are not exclusively due to the relay start, but primarily due to increased effort (Braun et al., 2021).
© Copyright 2023 XIVth International Symposium on Biomechanics and Medicine in Swimming Proceedings. Published by evoletics Media. All rights reserved.