Background/Objectives: Despite extensive research on caffeine’s (CAF’s) ergogenic effects, evidence regarding its impact on anaerobic performance in female athletes remains limited and inconclusive. The aim of this study was to investigate the acute effects of 6 mg/kg⁻¹ caffeine on anaerobic performance, functional strength, agility, and ball speed in female soccer players. Methods: A randomized, double-blind, placebo-controlled crossover design was employed. Thirteen moderately trained female soccer players (age: 21.08 ± 1.11 years; height: 161.69 ± 6.30 cm; weight: 59.69 ± 10.52 kg; body mass index (BMI): 22.77 ± 3.50 kg/m²; training age: 7.77 ± 1.16 years; habitual caffeine intake: 319 ± 160 mg/day) completed two experimental trials (caffeine vs. placebo (PLA)), separated by at least 48 h. Testing sessions included performance assessments in vertical jump (VJ), running-based anaerobic sprint test (RAST), bilateral leg strength (LS), handgrip strength (HS), single hop for distance (SH), medial rotation (90°) hop for distance (MRH), change of direction (COD), and ball speed. Rating of perceived exertion (RPE) was also recorded. Results: CAF ingestion significantly improved minimum (p = 0.011; d = 0.35) and average power (p = 0.007; d = 0.29) during RAST. A significant increase was also observed in SHR (single leg hop for distance right) performance (p = 0.045; d = 0.44). No significant differences were found in VJ, COD, ball speed, LS, HS, SHL, MRHR, or MRHL (p > 0.05). RPE showed a moderate effect size (d = 0.65) favoring the CAF condition, though not statistically significant (p = 0.110). Conclusions: In conclusion, acute CAF intake at a dose of 6 mg/kg⁻¹ may enhance anaerobic capacity and lower-limb functional strength in female soccer players, with no significant effects on jump height, agility, or upper-body strength.

Caffeine (CAF) has been shown to be an effective ergogenic aid in enhancing sports performance, including vertical jump (VJ), sprint, balance, agility, and freestyle swimming performance (FSP). However, whether acute CAF supplementation improves FSP in moderately trained female swimmers has not been well documented. Therefore, this study aimed to investigate the effects of CAF intake on vertical jump, balance, auditory reaction time (ART), and swimming performance in female swimmers. In a double-blind, cross-over design, eight moderately trained female swimmers (age: 21.3 ± 1.4 years, height: 161.2 ± 7.1 cm, body mass: 56.3 ± 6.7 kg, body mass index (BMI): 21.9 ± 1.3 kg/m², and habitual CAF intake: 246.4 ± 111.4 mg/day) ingested caffeine (CAF) (6 mg/kg) or a placebo (PLA) 60 min before completing VJ, balance, ART, and 25/50 m FSP. CAF supplementation resulted in a significantly lower time both in 25m (p = 0.032) and 50m (p = 0.033) FSP. However, CAF resulted in no significant difference in VJ, ART, and RPE (p > 0.05). Balance test results showed a non-significant moderate main effect (d = 0.58). In conclusion, CAF seems to reduce time in short-distance swimming performances, which could be the determinant of success considering the total time of the race. Thus, we recommend coaches and practitioners incorporate CAF into swimmers’ nutrition plans before competitions, which may meet the high performance demands.

The effects of L-citrulline or L-arginine supplementation on exercise performance are equivocal, and the effects on swimming performance are unclear. We aimed to assess whether 8-day supplementation with L-arginine or L-citrulline supplementation would improve 200 m and 100 m freestyle swimming time-trial performances. After the baseline trial (first visit), in a double-blind, randomised design, 15 trained/developmental (5 females) swimmers and triathletes were assigned to three groups and underwent an 8-day supplementation period, with a daily dose of either 8 gr L-arginine (Arg, n = 5) or L-citrulline (Cit, n = 5) or placebo (Pla, n = 5). On day 9, participants completed experimental trial (second visit). In each trial, after blood sampling, participants performed both 200 m and 100 m freestyle swimming time-trials, with 30 min recovery between trials. Plasma nitric oxide (NOx) and blood lactate concentrations (BLa) were collected immediately before and after 200 m and 100 m TTs, respectively. No significant difference was observed in NOx between groups (p = 0.201). There was no significant difference in 200 m (p = 0.226) and 100 m swimming time-trials (p = 0.993) between groups. There was a main effect of time on BLa concentration (p < 0.001), but no trial × group (p = 0.243) and trial × lactate × group interaction effect (p = 0.276) was present. Furthermore, 8-day either L-citrulline or L-arginine supplementation did not enhance middle (200 m) and short-distance (100 m) swimming performance in trained/developmental swimmers and triathletes. These findings do not support the use of L-citrulline or L-arginine supplementation as ergogenic aids for swimming performance.

The present study aims to test the reliability and validity of ÇAĞIN Hand and Foot Reaction Tests. A total of 120 athletes, 60 under the age of 18 and 60 over the age of 18 who were actively playing soccer, participated in the study. ÇAĞIN Hand and Foot Reaction Tests were applied to the athletes participating in the study 3 times with 2-week intervals using FitLight Trainer and BlazePod devices. In order to determine the validity of the data obtained from the athletes by applying ÇAĞIN Hand and Foot Reaction Tests, two measurements made with the FitLight Trainer device at different times were compared, and in order to determine the reliability, measurements made with the FitLight Trainer and BlazePod device on different days were compared and analyzed. Paired Simple T-Test in SPSS 26.0 package program was applied to determine both validity and reliability. According to the findings obtained, the validity and reliability correlation coefficients of all 6 tests in the ÇAĞIN Hand and Foot Reaction Tests were found to be r>0.70 (p<0.05). In the light of these findings, it was determined that the validity and reliability of ÇAĞIN Hand and Foot Reaction Tests were very high (r= 0.70-0.90).

Tennis matches were won based on factors like technique and strategy when wooden rackets were in use. But today, with the increase in technology, fiber carbon rackets, and advanced racket string are used in matches. This has increased the game structure of tennis to high-intensity levels. Players need to improve their physical capacity to perform at this level. Because tennis has shifted towards a branch where not only technical capacity is not enough, and strength, power, speed, and endurance are also at the forefront. Some performance tests are conducted to develop and monitor these motoric characteristics. Sport-specific technical skills and a high physical performance profile are the dominant factors in tennis. Conditioning test batteries help to analyze the performance levels of amateur and elite-level tennis players at different levels in the laboratory and on the court. In line with this view, some tennis-specific field tests have been developed in the literature. At the same time, these tests have been compared with laboratory tests and have validity and reliability. Thanks to these developed tests, it provides the opportunity to determine the performance profile of the individual at different times of the year and to adjust the individual training program individually according to these test results. Therefore, this review aims to describe and evaluate the different performance tests recommended and used by performance coaches, sports scientists, and organizations (national tennis federations).

The aim of this study was two-fold: (i) to test the concurrent validity of the Speedtrack X radar device for measuring tennis ball speed in comparison to a Pocket radar gun and (ii) to test the intra-unit reliability of the Speedtrack X radar device for measuring tennis ball speed. A total sample of 116 tennis ball throws performed by the same machine were measured in a single session. All throws were simultaneously measured by one Pocket radar device (reference criterion) and one Speedtrack X radar gun. Reliability levels were calculated using Pearson’s correlation test ( r ), the intra-class correlation test (ICC), and coefficient of variation (CV), while concurrent validity was tested using Bland-Altman and effect size (for measuring between-device differences). High correlation between the data obtained from the two devices was found ( r = 0.932, p < 0.001). The ICC of the measurements of the data obtained from the two devices is high ( r = 0.964, p < 0.001). The results allow us to conclude that the Speedtrack X radar gun is valid and reliable for measuring tennis ball speed.