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

Abstract

The aim of the present study was to examine the effects of time of day on stroke parameters and motor organization in front-crawl swimmers. In a randomized order, fourteen regional swimmers (age: 18.7 ± 1.6 years) performed maximal front crawls over 12.5m during two experimental sessions; the morning sessions were conducted between 07:00 and 09:00 h and the evening experiments were conducted between 17:00 and 19:00 h. Stroke parameters (swim velocity, stroke rate and stroke length), motor organization (arm stroke phases and arm coordination) were calculated from aerial and underwater side-view cameras. Arm coordination was quantified in terms of an index of coordination (Idc). Results showed that oral temperature was significantly higher in the evening 36.8 ± 0.2°C than in the morning 36.1 ± 0.2°C (p < 0.001), with a morning-evening differences of -0.7 ± 0.1°C. Performance was also higher in the evening (7.4 ± 0.6 s) than in the morning (8.0 ± 0.8 s) (p < 0.001), with a morning-evening differences of 0.55 ± 0.30 s. Likewise, values of swim velocity and stroke rate were higher in the evening than in the morning (p < 0.001) with morning-evening differences of -0.10 ± 0.04 m.s -1 and -3.99 ± 2.91 cycles.min -1 , respectively. Percentage IdC increased significantly (p < 0.01) between the morning (-5.1 ± 6.5%) and evening (-1.6 ± 7.0%). It is concluded that maximal swimming trials are performed better in the evening than the morning, and that this might be explained by better stroke parameters and motor organization at this time.

Does Ramadan Fasting Affect Diurnal Variation on Swimming Performance and Anaerobic Power?

“…In addition, data indicate that swimming performance was better in the evening than the morning, with higher evening values for V and SR, possibly explaining the better swimming performance at this time. Circadian variations in maximum swimming performance have previously been shown in other studies (Baxter & Reilly, 1983;Ferchichi et al, 2015Ferchichi et al, , 2016Kline et al, 2007). In the present study, even though V was significantly higher in the evening compared to the morning, the mechanisms responsible for such variation are poorly understood.…”

“…In swimming, maximal muscle strength at a given velocity [i.e., power] and stroke parameters [i.e., swim speed (V), stroke rate (SR) and stroke length (SL)] are factors of great importance for performance. Also, morning-evening differences increase with the complexity of motor tasks; this effect has been reported not only with regard to overall performance but also with regard to its different components, such as maximal power and technical ability (Ferchichi et al, 2015(Ferchichi et al, , 2016 In view of the above considerations, the aim of the study is to examine the effect of Ramadan fasting on the diurnal variations of maximal cycle power and stroke parameters and consequently on swimming performance. We are not aware of any experimental evidence regarding effects of Ramadan fasting on the diurnal variations in stroke parameters in front crawl swimmers and overall swimming performance, and so the present study attempts to provide insights in this area.…”

Time of Day Effect on Repeated Sprint Ability, Aerobic Capacity, and Physiological Responses in Team-Sport Athletes

“…It was observed that the body temperature was higher in the evening hours. Ferchichi et al, (2015) found that the oral temperature was higher in the evening (17.00-19.00) than in the morning (07.00-09.00am).…”

“…It was also found that lung function was better in the evening. Ferchichi et al (2015) emitted that maximal swimming performances of swimmers were better in the evening than in the morning. Swimming speed, stroke rate, stroke length and motor organization parameters were found better in the evening hours.…”