The aim of this study was to examine the effect of intensive practice in table tennis on perceptual coincident timing. The main question was whether the perceptual demands encountered in fast ball sports produce modifications of the perceptual visual system. Expert table tennis players and novices were compared in a perceptual task which consisted of estimating, by pressing a key, the arrival of a moving stimulus at a target. The stimulus, which was presented either at constant velocity or at constant deceleration, reproduced as closely as possible the natural visual demands encountered in table tennis. The difference between the time of response and the time of arrival of the stimulus at a target position was measured over 40 trials for each of the 16 participants. The results showed no effect of expertise under the constant-velocity condition but an effect under the decelerative condition, indicating that experts were less trajectory-dependent than novices. This result was interpreted as reflecting a better adaptation of the perceptual system of experts to the constraints encountered during table tennis and specifically to the perceptual demands resulting from varied and decelerated ball trajectories. Finally, some limitations of the coincidence anticipation procedure are highlighted, concerning its use in practical settings for evaluating athletes or detecting sport talents, and the need for the simulation conditions during testing to reproduce as closely as possible the perceptual demands of real life is discussed.

Purpose: To investigate the accuracy of ChatGPT (Chat generative pretrained transformer), a large language model, in calculating sample size for sport-sciences and sports-medicine research studies. Methods: We conducted an analysis on 4 published papers (ie, examples 1–4) encompassing various study designs and approaches for calculating sample size in 3 sport-science and -medicine journals, including 3 randomized controlled trials and 1 survey paper. We provided ChatGPT with all necessary data such as mean, percentage SD, normal deviates (Z_α/2 and Z_1−β), and study design. Prompting from 1 example has subsequently been reused to gain insights into the reproducibility of the ChatGPT response. Results: ChatGPT correctly calculated the sample size for 1 randomized controlled trial but failed in the remaining 3 examples, including the incorrect identification of the formula in one example of a survey paper. After interaction with ChatGPT, the correct sample size was obtained for the survey paper. Intriguingly, when the prompt from Example 3 was reused, ChatGPT provided a completely different sample size than its initial response. Conclusions: While the use of artificial-intelligence tools holds great promise, it should be noted that it might lead to errors and inconsistencies in sample-size calculations even when the tool is fed with the necessary correct information. As artificial-intelligence technology continues to advance and learn from human feedback, there is hope for improvement in sample-size calculation and other research tasks. However, it is important for scientists to exercise caution in utilizing these tools. Future studies should assess more advanced/powerful versions of this tool (ie, ChatGPT4).

The present study aimed to investigate the concomitant effects of Ramadan intermittent fast (RIF) and muscle fatigue on neuromuscular performances and reaction times in young trained athletes. Eight karate players (17.2 ± 0.5 years) were tested on three sessions: during a control period (S1: one week before Ramadan), and during the first (S2) and the fourth week of RIF (S3). Dietary intake and anthropometric measurements were assessed before each session. During each test session, participants performed maximal voluntary isometric contractions (MVC) and a submaximal contraction at 75 % MVC until exhaustion (T lim ) of the right elbow flexors. Surface electromyography was recorded from biceps brachii muscle during MVC and T lim . Simple (SRT) and choice (CRT) reaction times were evaluated at rest and just after T lim in a random order. The total daily energy (S2: +19.5 %, p < 0.05; S3: +27.4 %, p < 0.01) and water (S2: +26.8 %, p < 0.01; S3: +23.2 %, p < 0.05) intake were significantly increased during RIF. However, neither body mass nor body mass index was altered by RIF (F (2,14) = 0.80, p = 0.47 and F (2,14) = 0.78, p = 0.48, respectively). In addition, T lim (F (2,14) = 2.53, p = 0.12), MVC (F (2,14) = 0.51, p = 0.61) and associated electrical activity (F (2,14) = 0.13, p = 0.88) as well as neuromuscular efficiency (F (2,14) = 0.27, p = 0.76) were maintained during RIF. Moreover, neither SRT nor CRT was affected by RIF (F (2,14) = 1.82, p = 0.19 and F (2,14) = 0.26, p = 0.78, respectively) or neuromuscular fatigue (F (1,7) = 0.0002, p = 0.98 and F (1,7) = 3.78, p = 0.09, respectively). The present results showed that RIF did not adversely affect the neuromuscular performances and anthropometric parameters of elite karate athletes who were undertaking their usual training schedule. In addition, neither RIF nor neuromuscular fatigue poorly affects reaction times in elite karate athletes.

BACKGROUND: Studies on the submaximal aerobic capacity of exclusive narghile smokers (ENS) seem necessary in view of effective prevention of cardiorespiratory diseases. The goal of the study was to assess, by 6-min walk test (6MWT) data, the submaximal aerobic capacity of ENS, to identify factors influencing their 6-min walk distance (6MWD), and to compare their data with those of a healthy non-smoker (HNS) group. METHODS: Seventy 20–60-y-old male ENS were included. Narghile use (narghile-years) and anthropometric, clinical, spirometric, and 6MWT data were collected. Univariate and multivariate analyses were used to identify factors influencing 6MWD. Data of a subgroup of 40–60-y-old ENS ( n = 25) were compared with those of an age-matched HNS group ( n = 53). RESULTS: The median (first to third quartile) for age and narghile use were 32 (26–43) and 17 (8–32) narghile-years, respectively. The profile of ENS performing the 6MWT was as follows: at the end of the 6MWT, 34% and 9% had a low heart rate (< 60% of maximum predicted) and high dyspnea scores (> 5/10, visual analog scale), respectively; 3% had an oxyhemoglobin saturation decrease of > 5 points during the test; and 20% had an abnormal 6MWD (less than the lower limit of the normal range). The factors that significantly influenced the 6MWD, explaining 38% of its variability, are included in the following equation: 6MWD (m) = 742.63 − 5.20 × body mass index (kg/m ² ) + 25.23 × FEV ₁ (L) − 0.44 × narghile use (narghile-years). Compared with HNS, the subgroup of ENS had a significantly lower 6MWD (98 ± 7 vs 87 ± 9% predicted, respectively). CONCLUSIONS: Narghile use may play a role in reducing submaximal aerobic capacity. The present study suggests that a program of pulmonary rehabilitation is an excellent axis to follow.