Effects of protein-carbohydrate vs. carbohydrate alone supplementation on immune inflammation markers in endurance athletes: a randomized controlled trial.

PURPOSE: The impact of ingesting carbohydrates alone or combined with proteins to support exercise immune adaptation in endurance athletes is scarcely investigated. The present study compares the effect of ingesting a combined protein-carbohydrate supplement vs. a carbohydrate-only supplement post-workout on immune inflammation markers following a 10 week periodized endurance training program in well-trained athletes. METHODS: Twenty-five men completed the study after being randomly assigned to one of the following intervention groups: combined protein-carbohydrate (PRO-CHO n = 12, 31 ± 9 years, [Formula: see text]O2peak 61.0 ± 5.6 ml.kg-1.min-1) or non-protein isoenergetic carbohydrate (CHO, n = 13, 33 ± 8 years, [Formula: see text]O2peak 60.6 ± 6.9 ml.kg-1.min-1). Treatment consisted of ingesting 24 g of assigned supplement, mixed with 250 ml of orange juice, once a day for 10 weeks immediately post-workout (or before breakfast on non-training days). Measurements were conducted pre- and post-intervention on total leukocytes, leukocyte subsets (i.e., neutrophils, eosinophils, basophils, monocytes, and lymphocytes), and platelets. The inflammatory status was assessed by the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), and the systemic-immune inflammation index (SII). RESULTS: Post-intervention, significant increases were observed for CHO group only for the three inflammatory markers: NLR (p = 0.050, d = 0.58), PLR (p = 0.041, d = 0.60), and SII (p = 0.004, d = 0.81) but not for PRO-CHO (p > 0.05). CONCLUSION: Ingesting a post-workout protein-carbohydrate combined beverage promoted a more favourable immune status than carbohydrate-only ingestion by attenuating cellular inflammation over a 10 week training period in endurance male athletes. TRIAL REGISTRATION: The study was registered in ClinicalTrials.gov with the following ID: NCT02954367. The study was registered by 3 November 2016.

Influencia del cambio de uso del suelo sobre las reservas de carbono orgánico en el Parque Natural Regional Cortadera, Boyacá (Colombia)

Los páramos almacenan grandes reservas de carbono orgánico en el suelo (COS), influenciados por las condiciones climáticas y biogeoquímicas, propias del ecosistema; sin embargo, su progresiva conversión hacia cultivos, ganadería o minería incide directamente en las reservas de COS. Con el fin de determinar el efecto que ejerce el cambio de uso de suelo sobre la variabilidad de las reservas de COS, se realizó un monitoreo de COS entre 2013, 2018 y 2020, en el Parque Natural Regional Cortadera. Se estudiaron parcelas permanentes de muestreo (PPM), ubicadas bajo tres diferentes usos del suelo: conservado, en recuperación e intervenido. Se analizaron muestras de carbono orgánico y densidad aparente, a dos profundidades (0-15 cm y 15-30 cm). Se encontró que la PPM en escenario conservado presentó los contenidos más altos de COS, con valores de 290,37; 199,22 y 257,5 tC ha-1, para cada uno de los años en estudio; seguido por la PPM en recuperación, que evidenció valores de COS 215,3 tC ha-1, en el 2020, en contraste con la PPM intervenida, que presentó contenidos mínimos de 15,50; 34,01 y 88,06 tC ha-1. Se observó que los mayores contenidos de COS se encuentran a la profundidad de 15 a 30 cm. Dichos aspectos, resaltan la importancia de avanzar en acciones enfocadas a la protección de ecosistemas estratégicos, considerando las constantes amenazas relacionadas con la transformación del paisaje y, con ello, la posibilidad de proveer funciones y servicios asociados a la captura de carbono y la regulación climática.

The paramos accumulate high stocks of soil organic carbon (SOC), influenced by the climatic and biogeochemical conditions of the ecosystem. However, their progressive conversion to crops, livestock, or mining has a direct impact on the SOC stocks. To determine the effect of land use change on the variability of SOC stocks, monitoring of SOC content was conducted between the years 2013, 2018, and 2020 in the Parque Natural Regional Cortadera. Permanent sampling plots (PPS) located under three different land uses were studied: conserved, recovering, and intervened. To do so, samples of soil organic carbon and bulk density at two depths were analyzed (0-15 cm and 15-30 cm). The conserved PPS showed the highest SOC contents, with maximum values of 290.37; 199.22, and 257.5 tC ha-1 for each of the years under study; follow by the recovery PPM that presented COS values of 215.3 tC ha-1 in 2020, in contrast to the intervened PSP that showed minimum contents of 15.50; 34.01 and 88.06 tC ha-1. Furthermore, the highest SOC contents were found at 15-30 cm depth. These factors emphasize the importance of carrying out actions focused on protecting strategic ecosystems such as paramos, taking into account the continuous threats related to the transformation of the landscape and, consequently, the possibility of providing ecosystem functions and services related to carbon capture and climate regulation.

Anti-Doping Knowledge of Students Undertaking Bachelor's Degrees in Sports Sciences in Spain.

In Spain, students pursuing a career in athletic training, physical education, or scientific evaluation of sports enroll in a bachelor's degree in sports sciences. This degree provides knowledge and skills in a broad array of sports settings and promotes research-based interdisciplinary knowledge. However, the student's syllabus rarely includes specific academic training on anti-doping regulations or doping prevention. The purpose of this study was to assess the anti-doping knowledge of the students undertaking a bachelor's degree in sports sciences in Spanish universities. One thousand two hundred and thirty-three bachelor students in sport science (907 males, 322 females, and 4 participants with non-binary sex) from 26 Spanish universities completed a validated questionnaire about general anti-doping knowledge. The questionnaire is an adapted version of the Play True Quiz of the World Anti-Doping Agency and contains 37 multiple-choice questions. The score obtained in the questionnaire was transformed into a 0−100-point scale. The questionnaire was distributed among students within each university by a faculty member and it was filled out online. Students obtained a score of 65.8 ± 10.10 points (range = 32−92 points). There was an effect of the course in the score obtained (p < 0.001). Students of the first course (63.6 ± 9.5 points) had lower scores than the remaining courses (p < 0.037) while the students of the fourth course obtained the highest scores (68.7 ± 9.5 points; p < 0.019). The students with an itinerary on sports performance were the respondents with the highest anti-doping knowledge (67.2 ± 10.2) points, followed by the students with an itinerary on health (66.7 ± 9.5 points). The knowledge of basic anti-doping rules and doping prevention strategies of the bachelor students in sports sciences in Spain was suboptimal. Increasing doping prevention information in the syllabus of the bachelor's degree in sports sciences is essential as these future professionals will directly work with populations at risk of doping.

Flavanol-Rich Cocoa Supplementation Inhibits Mitochondrial Biogenesis Triggered by Exercise.

The potential role of cocoa supplementation in an exercise context remains unclear. We describe the effects of flavanol-rich cocoa supplementation during training on exercise performance and mitochondrial biogenesis. Forty-two male endurance athletes at the beginning of the training season received either 5 g of cocoa (425 mg of flavanols) or maltodextrin (control) daily for 10 weeks. Two different doses of cocoa (equivalent to 5 g and 15 g per day of cocoa for a 70 kg person) were tested in a mouse exercise training study. In the athletes, while both groups had improved exercise performance, the maximal aerobic speed increased only in the control group. A mitochondrial DNA analysis revealed that the control group responded to training by increasing the mitochondrial load whereas the cocoa group showed no increase. Oxidative stress was lower in the cocoa group than in the control group, together with lower interleukin-6 levels. In the muscle of mice receiving cocoa, we corroborated an inhibition of mitochondrial biogenesis, which might be mediated by the decrease in the expression of nuclear factor erythroid-2-related factor 2. Our study shows that supplementation with flavanol-rich cocoa during the training period inhibits mitochondrial biogenesis adaptation through the inhibition of reactive oxygen species generation without impacting exercise performance.

Acute effects of dynamic versus foam rolling warm-up strategies on physical performance in elite tennis players.

To date, there is a lack of information about the optimal conditions of the warm-up to lead to a better performance in elite tennis players. The aim of this study was to compare the effects of two different warm-up protocols (dynamic vs. self-myofascial release with foam rolling) on neuromuscular variables associated with physical determinants of tennis performance. Using a crossover randomised experimental design, eleven professional men tennis players (20.6 ± 3.5 years) performed either a dynamic warm-up (DWU) or a self-myofascial release with foam rolling (SMFR) protocol. DWU consisted of 8 min of dynamic exercises at increasing intensity and SMFR consisted of 8 min of rolling on each lower extremity unilaterally. Just before (baseline) and after completing warm-up protocols, players performed a countermovement jump (CMJ), the 5-0-5 agility test, a 10-m sprint test and the Straight Leg Raise and Thomas tests to assess range of motion. Compared to baseline, the DWU was more effective to reduce the time in the 5-0-5 test than SMFR (-2.23 vs. 0.44%, respectively, p = 0.042, ηp2 = 0.19). However, both warm-up protocols similarly affected CMJ (2.32 vs. 0.61%, p = 0.373, ηp2 = 0.04) and 10-m sprint time changes (-1.26 vs. 1.03%, p = 0.124, ηp2 = 0.11). Changes in range of motion tests were also similar with both protocols (p = 0.448-1.000, ηp2 = 0.00-0.02). Overall, both DWU and SMFR were effective to prepare well-trained tennis players for highly demanding neuromuscular actions. However, DWU offered a better preparation for performing change of direction and sprint actions, and hence, in high-performance tennis players, the warm-up should include dynamic exercises.

The effect of acute moderate-intensity exercise on the serum and fecal metabolomes and the gut microbiota of cross-country endurance athletes.

Physical exercise can produce changes in the microbiota, conferring health benefits through mechanisms that are not fully understood. We sought to determine the changes driven by exercise on the gut microbiota and on the serum and fecal metabolome using 16S rRNA gene analysis and untargeted metabolomics. A total of 85 serum and 12 fecal metabolites and six bacterial taxa (Romboutsia, Escherichia coli TOP498, Ruminococcaceae UCG-005, Blautia, Ruminiclostridium 9 and Clostridium phoceensis) were modified following a controlled acute exercise session. Among the bacterial taxa, Ruminiclostridium 9 was the most influenced by fecal and serum metabolites, as revealed by linear multivariate regression analysis. Exercise significantly increased the fecal ammonia content. Functional analysis revealed that alanine, aspartate and glutamate metabolism and the arginine and aminoacyl-tRNA biosynthesis pathways were the most relevant modified pathways in serum, whereas the phenylalanine, tyrosine and tryptophan biosynthesis pathway was the most relevant pathway modified in feces. Correlation analysis between fecal and serum metabolites suggested an exchange of metabolites between both compartments. Thus, the performance of a single exercise bout in cross-country non-professional athletes produces significant changes in the microbiota and in the serum and fecal metabolome, which may have health implications.

Effects of adding post-workout microcurrent in males cross country athletes.

Post-exercise microcurrent based treatments have shown to optimise exercise-induced adaptations in athletes. We compared the effects of endurance training in combination with either, a microcurrent or a sham treatment, on endurance performance. Additionally, changes in body composition, post-exercise lactate kinetics and perceived delayed onset of muscle soreness (DOMS) were determined. Eighteen males (32.8 ± 6.3 years) completed an 8-week endurance training programme involving 5 to 6 workouts per week wearing a microcurrent (MIC, n=9) or a sham (SH, n=9) device for 3-h post-workout or in the morning during non-training days. Measurements were conducted at pre- and post-intervention. Compared to baseline, both groups increased (P < 0.01) maximal aerobic speed (MIC, pre = 17.6 ± 1.3 to post=18.3 ± 1.0; SH, pre=17.8 ± 1.5 to post = 18.3 ± 1.3 km.h-1) with no changes in V˙O2peak. No interaction effect per group and time was observed (P=0.193). Although both groups increased (P < 0.05) trunk lean mass (MIC, pre=23.2 ± 2.7 to post=24.2 ± 2.0; SH, pre=23.4 ± 1.7 to post=24.3 ± 1.6 kg) only MIC decreased (pre=4.8 ± 1.5 to post=4.5 ± 1.5, p=0.029) lower body fat. At post-intervention, no main differences between groups were observed for lactate kinetics over the 5 min recovery period. Only MIC decreased (P<0.05) DOMS at 24-h and 48-h, showing a significant average lower DOMS score over 72-h after the completion of the exercise-induced muscle soreness protocol. In conclusion, a 3-h daily application of microcurrent over an 8-week endurance training programme produced no further benefits on performance in endurance-trained males. Nonetheless, the post-workout microcurrent application promoted more desirable changes in body composition and attenuated the perception of DOMS over 72-h post-exercise.

Effect of a Blend of Zingiber officinale Roscoe and Bixa orellana L. Herbal Supplement on the Recovery of Delayed-Onset Muscle Soreness Induced by Unaccustomed Eccentric Resistance Training: A Randomized, Triple-Blind, Placebo-Controlled Trial.

BACKGROUND: There is an increasing interest in the use of eccentric muscle exercise to improve physical condition, especially with regards to its health-related benefits. However, it is known that unaccustomed eccentric exercise causes muscle damage and delayed pain, commonly defined as "delayed onset muscle soreness" (DOMS). The efficacy of herbal preparations in subjects suffering from DOMS has been reported in a few previous studies with small or moderate outcome measures related to muscle recovery. The present study aimed to evaluate the effects of a polyherbal mixture containing whole Zingiber officinale Roscoe and Bixa orellana L., powders called ReWin(d), in young male athletes suffering from DOMS induced by a 1 h session of plyometric exercises. METHODS: Thirty-three young male athletes participated in this randomized, Triple-blind, placebo-controlled trial: 17 of them assigned to the ReWin(d) group and 16 of them to the placebo group. Creatine kinase (CK) was measured as a muscle damage marker, pain was assessed using the Visual Analog Scale (VAS), muscle performance was measured through half-squat exercise (HS) monitored with an accelerometer (Encoder), and heart rate variability (HRV) was monitored for 5 min with the subjects in the supine position. All determinations were performed before and after the eccentric session and 24, 48, and 72 h after the session. RESULTS: The eccentric exercise session caused an increase in CK at 24 and 48 h after exercise intervention in both groups (p < 0.001). There was no interaction between groups regarding muscle damage. The pain increased after the training session in both groups (p < 0.001), and a significant interaction was observed between groups at 48 h after exercise (p = 0.004). Lower limb muscular power showed a significant interaction between groups 24 h after exercise (p = 0.049); the placebo group showed a reduction in muscle power compared to the ReWin(d) group. The LF/HF ratio decreased significantly at 72 h after exercise in the herbal group but not in the placebo group. CONCLUSION: The herbal supplement maintained the maximum power of the lower limbs and attenuated muscle pain. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier NCT03961022.

Chronic flavanol-rich cocoa powder supplementation reduces body fat mass in endurance athletes by modifying the follistatin/myostatin ratio and leptin levels.

Flavanols-rich cocoa has positive effects on lipid metabolism and might enhance the performance of athletes through an improvement in their body composition. To test this hypothesis a placebo-controlled intervention study in training endurance athletes who received 5 g of cocoa daily (425 mg of flavanols) for 10 weeks was performed. Dietary intake, body composition, exercise performance and plasma levels of follistatin, myostatin and leptin were measured. Cocoa intake significantly reduced body fat percentage (p = 0.020), specifically in the trunk (p = 0.022), visceral area (p = 0.034) and lower limbs (p = 0.004). The reduction in body fat mass was accompanied by an increase in plasma follistatin and a decrease in leptin, while myostatin levels remained unchanged. The intake of cocoa reduced the percentage of body fat of athletes, without any impact on athletes' performance. The change in fat body composition did not improve athletes' performance.

Muscle Activation in Middle-Distance Athletes with Compression Stockings.

The aim of this study was to evaluate changes in electromyographic activity with the use of gradual compression stockings (GCSs) on middle-distance endurance athletes' performance, based on surface electromyography measurement techniques. Sixteen well-trained athletes were recruited (mean ± SD: age 33.4 ± 6.3 years, VO2max 63.7 ± 6.3 mL·kg-1·min-1, maximal aerobic speed 19.7 ± 1.5 km·h). The athletes were divided into two groups and were assigned in a randomized order to their respective groups according to their experience with the use of GCSs. Initially, a maximum oxygen consumption (VO2max) test was performed to standardize the athletes' running speeds for subsequent tests. Afterward, electromyographic activity, metabolic, and performance variables for each group were measured with surface electromyography. In addition, blood lactate concentration was measured, both with and without GCSs, during 10 min at 3% above VT2 (second ventilatory threshold), all of which were performed on the track. Next, surface electromyography activity was measured during a 1 km run at maximum speed. No significant changes were found in electromyography activity, metabolic and performance variables with GCSs use (p > 0.164) in any of the variables measured. Overall, there were no performance benefits when using compression garments against a control condition.

Effects of Beetroot Juice Ingestion on Physical Performance in Highly Competitive Tennis Players.

Beetroot juice (BJ) contains high levels of inorganic nitrate (NO3-) and its intake has good evidence in increasing blood nitrate/nitrite concentrations. The ingestion of BJ has been associated with improvements in physical performance of endurance sports, however the literature in intermittent sports is scarce. The aim of this study was to investigate whether BJ could improve physical performance in tennis players. Thirteen well-trained tennis players (25.4 ± 5.1 years) participated in the study during their preparatory period for the tennis season. Subjects were randomly divided into two groups and performed a neuromuscular test battery after either BJ or placebo (PLA) consumption. Both trials were executed on two separate days, in randomized order, with one week of wash out period. The test battery consisted of serve velocity test (SVT), countermovement jump (CMJ), isometric handgrip strength (IHS), 5-0-5 agility test (5-0-5), and 10 m sprint (10-m). No significant differences were found in SVT (1.19%; p = 0.536), CMJ (0.96%; p = 0.327), IHS (4.06%; p = 0.069), 5-0-5 dominant and nondominant side (1.11-2.02%; p = 0.071-0.191) and 10-m (1.05%; p = 0.277) when comparing BJ and PLA ingestion. Thus, our data suggest that low doses of BJ (70 mL) consumption do not enhance tennis physical performance.

Different psychophysiological responses to a high-intensity repetition session performed alone or in a group by elite middle-distance runners.

Internal training load refers to the degree of disturbance in psychophysiological homeostasis provoked by a training session and has been traditionally measured through session-RPE, which is the product of the session Rate of Perceived Exertion (RPE) and the duration. External training load refers to the actual physical work completed, and depends on session volume, intensity, frequency and density. Drafting, which is achieved by running closely behind another runner has been demonstrated to reduce the energy cost of running at a fixed speed and to improve performance. Therefore, it is hypothesised that psychophysiological responses might reflect different levels of internal load if training is performed individually or collectively. 16 elite middle-distance runners performed two high-intensity training sessions consisting of 4 repetitions of 500 m separated by 3 min of passive recovery. Sessions were performed individually and collectively. Times for each repetition, RPE, core affect (valence and felt arousal) and blood lactate concentrations [BLa] were measured after each repetition. Main time effect was significant and increased across repetitions for [BLa] and RPE (p < 0.001), and decreased for valence (p = 0.001). Main group effect was significant and values were higher when training individually for [BLa] (p = 0.003) and RPE (p = 0.001), and lower for valence (p = 0.001). No differential responses were found between conditions in terms of repeat time or felt arousal. Findings demonstrate that elite middle-distance athletes running collectively display lower levels of internal training load compared to running alone, despite external training load being similar.

Intake of Animal Protein Blend Plus Carbohydrate Improves Body Composition With no Impact on Performance in Endurance Athletes.

The impact of animal protein blend supplements in endurance athletes is scarcely researched. The authors investigated the effect of ingesting an admixture providing orange juice and protein (PRO) from beef and whey versus carbohydrate alone on body composition and performance over a 10-week training period in male endurance athletes. Participants were randomly assigned to a protein (CHO + PRO, n = 15) or a nonprotein isoenergetic carbohydrate (CHO, n = 15) group. Twenty grams of supplement mixed with orange juice was ingested postworkout or before breakfast on nontraining days. Measurements were performed pre- and postintervention on body composition (by dual-energy X-ray absorptiometry), peak oxygen consumption (V˙O2peak), and maximal aerobic speed. Twenty-five participants (CHO + PRO, n = 12; CHO, n = 13) completed the study. Only the CHO + PRO group significantly (p < .05) reduced whole-body fat (mean ± SD) (-1.02 ± 0.6 kg), total trunk fat (-0.81 ± 0.9 kg), and increased total lower body lean mass (+0.52 ± 0.7 kg), showing close to statistically significant increases of whole-body lean mass (+0.57 ± 0.8 kg, p = .055). Both groups reduced (p < .05) visceral fat (CHO + PRO, -0.03 ± 0.1 kg; CHO, -0.03 ± 0.5 kg) and improved the speed at maximal aerobic speed (CHO + PRO, +0.56 ± 0.5 km/hr; CHO, +0.35 ± 0.5 km/hr). Although consuming animal protein blend mixed with orange juice over 10 weeks helped to reduce fat mass and to increase lean mass, no additional performance benefits in endurance runners were observed.

Effect of a Protein Supplement on the Gut Microbiota of Endurance Athletes: A Randomized, Controlled, Double-Blind Pilot Study.

Nutritional supplements are popular among athletes to improve performance and physical recovery. Protein supplements fulfill this function by improving performance and increasing muscle mass; however, their effect on other organs or systems is less well known. Diet alterations can induce gut microbiota imbalance, with beneficial or deleterious consequences for the host. To test this, we performed a randomized pilot study in cross-country runners whose diets were complemented with a protein supplement (whey isolate and beef hydrolysate) (n = 12) or maltodextrin (control) (n = 12) for 10 weeks. Microbiota, water content, pH, ammonia, and short-chain fatty acids (SCFAs) were analyzed in fecal samples, whereas malondialdehyde levels (oxidative stress marker) were determined in plasma and urine. Fecal pH, water content, ammonia, and SCFA concentrations did not change, indicating that protein supplementation did not increase the presence of these fermentation-derived metabolites. Similarly, it had no impact on plasma or urine malondialdehyde levels; however, it increased the abundance of the Bacteroidetes phylum and decreased the presence of health-related taxa including Roseburia, Blautia, and Bifidobacterium longum. Thus, long-term protein supplementation may have a negative impact on gut microbiota. Further research is needed to establish the impact of protein supplements on gut microbiota.

Is Marathon Training Harder than the Ironman Training? An ECO-method Comparison.

Purpose: To compare the absolute and relative training load of the Marathon (42k) and the Ironman (IM) training in recreational trained athletes. Methods: Fifteen Marathoners and Fifteen Triathletes participated in the study. Their performance level was the same relative to the sex's absolute winner at the race. No differences were presented neither in age, nor in body weight, height, BMI, running VO2max max, or endurance training experience (p > 0.05). They all trained systematically for their respective event (IM or 42k). Daily training load was recorded in a training log, and the last 16 weeks were compared. Before this, gas exchange and lactate metabolic tests were conducted in order to set individual training zones. The Objective Load Scale (ECOs) training load quantification method was applied. Differences between IM and 42k athletes' outcomes were assessed using Student's test and significance level was set at p < 0.05. Results: As expected, Competition Time was significantly different (IM 11 h 45 min ± 1 h 54 min vs. 42k 3 h 6 min ± 28 min, p < 0.001). Similarly, Training Weekly Avg Time (IM 12.9 h ± 2.6 vs. 42k 5.2 ± 0.9), and Average Weekly ECOs (IM 834 ± 171 vs. 42k 526 ± 118) were significantly higher in IM (p < 0.001). However, the Ratio between Training Load and Training Time was superior for 42k runners when comparing ECOs (IM 65.8 ± 11.8 vs. 42k 99.3 ± 6.8) (p < 0.001). Finally, all ratios between training time or load vs. Competition Time were superior for 42k (p < 0.001) (Training Time/Race Time: IM 1.1 ± 0.3 vs. 42k 1.7 ± 0.5), (ECOs Training Load/Race Time: IM 1.2 ± 0.3 vs. 42k 2.9 ± 1.0). Conclusions: In spite of IM athletes' superior training time and total or weekly training load, when comparing the ratios between training load and training time, and training time or training load vs. competition time, the preparation of a 42k showed to be harder.

Circadian rhythm effect on physical tennis performance in trained male players.

To determine the effect of circadian rhythm on neuromuscular responses and kinematics related to physical tennis performance, after a standardised warm-up, 13 highly competitive male tennis players were tested twice for serve velocity/accuracy (SVA), countermovement vertical jump (CMJ), isometric handgrip strength (IS), agility T-test (AGIL) and a 10-m sprint (10-m RUN). In a randomised, counter-balance order, tennis players underwent the test battery twice, either in the morning (i.e., AM; 9:00 h) and in the afternoon (i.e., PM; 16:30 h). Paired t-tests were used to analyse differences due to time-of-day in performance variables. Comparison of morning versus afternoon testing revealed that SVA (168.5 ± 6.5 vs. 175.2 ± 6.1 km · h-1; P = 0.003; effect size [ES] = 1.07), CMJ (32.2 ± 0.9 vs. 33.7 ± 1.1 cm; P = 0.018; ES = 1.46), AGIL (10.14 ± 0.1 vs. 9.91 ± 0.2 s; P = 0.007; ES = 1.23) and 10-m RUN time (1.74 ± 0.1 vs. 1.69 ± 0.1 s; P = 0.021; ES = 0.67) were significantly blunted during the morning testing. However, IS was not affected by time-of-day (P = 0.891). Thus, tennis performance may be reduced when competing in the morning in comparison to early evening. Therefore, coaches and tennis players should focus on schedule the SVA, power, speed and agility training sessions in the afternoon.