Diurnal Variation in Swim Performance Remains, Irrespective of Training Once or Twice Daily

Abstract

Purpose: Fast swim times in morning rounds are essential to ensure qualification in evening finals. A significant time-of-day effect in swimming performance has consistently been observed, although physical activity early in the day has been postulated to reduce this effect. The aim of this study was to compare intradaily variation in race-pace performance of swimmers routinely undertaking morning and evening training (MEG) with those routinely undertaking evening training only (EOG). Methods: Each group consisted of 8 swimmers (mean ± SD: age = 15.2 ± 1.0 and 15.4 ± 1.4 y, 200-m freestyle time 132.8 ± 8.4 and 136.3 ± 9.1 s) who completed morning and evening trials in a randomized order with 48 h in between on 2 separate occasions. Oral temperature, heart rate, and blood lactate were assessed at rest, after a warm-up, after a 150-m race-pace swim, and after a 100-m time trial. Stroke rate, stroke count, and time were recorded for each length of the 150-m and 100-m swims. Results: Both training groups recorded significantly slower morning 100-m performances (MEG = +1.7 s, EOG = +1.4 s; P < .05) along with persistently lower morning temperatures that on average were -0.47°C and -0.60°C, respectively (P < .05). No differences were found in blood-lactate, heart-rate, and stroke-count responses (P > .05). All results were found to be reproducible (P > .05). Conclusions: The long-term use of morning training does not appear to significantly reduce intradaily variation in race-pace swimming or body temperature.

Diurnal variation in stroke parameters and motor organization in front-crawl swimmers

“…In conclusion, the present results confirm those of previous studies Kline et al 2007;Martin et al 2007;Zarouk et al 2012) that showed swimming performance to be greater in the evening than morning. This difference was associated with changes in stroke parameters (i.e.…”

“…The aim of this study was to analyze stroke parameters and arm coordination to better explain time-of-day effects in swim performance during a test of maximum velocity using the front Circadian variations in swim performance have previously been shown in other studies comparing maximum swimming performance at different times of the day Kline et al 2007;Martin et al 2007;Zarrouk et al 2012), these studies observing significantly superior performance in the evening compared with the morning. For example, Baxter and Reilly (1983) observed evening improvements of 3.5% in 100 m and 2.5% in 400 m swim performance.The present study confirms the better performance in the evening than the morning.…”

“…Nevertheless, the literature generally indicates an early morning nadir and a peak performance in the late afternoon (Chtourou and Souissi 2012). In swimming, it has been shown that performance recorded during different trials shows diurnal and/or circadian variation Kline et al 2007;Martin et al 2007), with an amplitude of 3.5% for 100 m and 2.5% for 400 m .…”

Comparing Performance During Morning vs. Afternoon Training Sessions in Intercollegiate Basketball Players

“…Sinclair et al demonstrated higher isokinetic strength during afternoon compared with morning measurement (26). Similarly, swimming times have been found slower in the morning when compared with evening bouts, regardless of the time the swimmer is accustomed to training (4,12,15). It has been shown that soccer performance improves in the afternoon as well (18,21).…”

“…In addition, it has been reported that increasing sleep duration is associated with improvement in technical skills and performance in basketball players (14). In addition, decrements in sport performance in swimmers have been observed with slower swimming speeds in the morning compared with the afternoon (4,12,15). …”