E performance of young tennis players. The study was conducted on 36 elite tennis players (age 14 ± 2 years; body mass 55 ± 6 kg; body height 165 ± 6 cm; mean ± SD) participating in the national young tennis championship. Balance performance was assessed before and immediately after a tennis training session (pre-training and post-training, respectively). The balance assessment was performed with 2 different balance boards and the Biodex Stability System. In addition, dynamometric measurements of peak isokinetic moment in the knee flexors and extensors were performed pre and post tennis training session, to quantify the degree of muscle fatigue induced by the tennis training session. One-way analysis of variance with repeated measures was used to test for differences in balance performance and in isokinetic performance between pre and post tennis training session. The data analysis revealed no significant differences (p > 0.05) in balance performance, whereas there were significant differences in knee joint moment production between pre and post tennis training measures. Although the tennis training session of the present study had no significant effect (p > 0.05) on any of the balance performance indicators examined, there was a decline in balance performance, which suggests that different level of fatigue for an extended period (games) will have greater effect on balance performance. It is suggested that a tennis-specific balance exercise program should be included in the tennis training session....

The present study aimed to investigate whether acute L-citrulline supplementation would affect inspiratory muscle oxygenation and respiratory performance. Twelve healthy males received 6 g of L-citrulline or placebo in a double-blind crossover design. Pulmonary function (i.e., forced expired volume in 1 s, forced vital capacity and their ratio), maximal inspiratory pressure (MIP), fractional exhaled nitric oxide (NO^•), and sternocleidomastoid muscle oxygenation were measured at baseline, one hour post supplementation, and after an incremental resistive breathing protocol to task failure of the respiratory muscles. The resistive breathing task consisted of 30 inspirations at 70% and 80% of MIP followed by continuous inspirations at 90% of MIP until task failure. Sternocleidomastoid muscle oxygenation was assessed using near-infrared spectroscopy. One-hour post-L-citrulline supplementation, exhaled NO^• was significantly increased (19.2%; p < 0.05), and this increase was preserved until the end of the resistive breathing (16.4%; p < 0.05). In contrast, no difference was observed in the placebo condition. Pulmonary function and MIP were not affected by the L-citrulline supplementation. During resistive breathing, sternocleidomastoid muscle oxygenation was significantly reduced, with no difference noted between the two supplementation conditions. In conclusion, a single ingestion of 6 g L-citrulline increased NO^• bioavailability but not the respiratory performance and inspiratory muscle oxygenation.

It is unclear whether fatigue induced by a tennis training session influences the effectiveness of balance exercise training program. Thus, the purpose of the present study was to investigate whether a balance program is more effective when performed

The aim of the present study was to study the effects of cycling and pure concentric and pure eccentric high-intensity interval exercise (HIIE) on skeletal muscle (i.e., vastus lateralis) and cerebral oxygenation. Twelve healthy males (n = 12, age 26 ± 1 yr, body mass 78 ± 2 kg, height 176 ± 2 cm, body fat 17 ± 1% of body mass) performed, in a random order, cycling exercise and isokinetic concentric and eccentric exercise. The isokinetic exercises were performed on each randomly selected leg. The muscle and the cerebral oxygenation were assessed by measuring oxyhemoglobin, deoxyhemoglobin, total hemoglobin, and tissue saturation index. During the cycling exercise, participants performed seven sets of seven seconds maximal intensity using a load equal to 7.5% of their body mass while, during isokinetic concentric and eccentric exercise, they were performed seven sets of five maximal muscle contractions. In all conditions, a 15 s rest was adopted between sets. The cycling HIIE caused greater fatigue (i.e., greater decline in fatigue index) compared to pure concentric and pure eccentric isokinetic exercise. Muscle oxygenation was significantly reduced during HIIE in the three exercise modes, with no difference between them. Cerebral oxygenation was affected only marginally during cycling exercise, while no difference was observed between conditions. It is concluded that a greater volume of either concentric or eccentric isokinetic maximal intensity exercise is needed to cause exhaustion which, in turn, may cause greater alterations in skeletal muscle and cerebral oxygenation.

Soccer players are particularly vulnerable to musculoskeletal injuries, which not only impact their performance but also significantly affect sleep quality. Pain, inflammation, and psychological stress from injuries frequently lead to sleep disturbances, disrupting essential recovery processes. Moreover, poor sleep can increase the risk of reinjury, creating a cycle that hampers long-term athletic performance. This review synthesizes existing literature on the complex relationship between injury severity and sleep quality in soccer players. It explores how pain and inflammation contribute to sleep disturbances, how disrupted sleep alters recovery mechanisms, and how psychological stress exacerbates both injury outcomes and sleep disruptions. Additionally, it examines the long-term effects of poor sleep on recovery rates and reinjury risk, emphasizing its impact on career longevity. To address these challenges, this review highlights practical strategies for optimizing sleep, including effective pain management, improved sleep hygiene, relaxation techniques, and targeted nutritional interventions. The integration of sleep monitoring tools and individualized approaches can help coaches, trainers, and medical professionals prioritize sleep as a fundamental component of injury recovery. By acknowledging sleep as a key factor in both injury prevention and rehabilitation, this review underscores the need for a holistic approach to athlete care. Enhancing sleep quality can significantly improve recovery outcomes, reduce reinjury risks, and ultimately support sustained performance and well-being in soccer players.