Endurance Running Performance Research Articles

Acute dose-response effect of photobiomodulation therapy on 5-km running performance in trained runners: a randomized, double-blind, placebo-controlled, crossover study.

Photobiomodulation therapy (PBMT) has been advocated as a potential intervention to improve muscle performance and recovery in the health and sports context. However, the short- and long-term effects of PBMT on endurance running performance remain under-researched and controversial. The purpose of this study was to investigate the acute dose-response effect of PBMT with light-emitting diodes (LEDs) on endurance performance and rating of perceived exertion (RPE; 6-20 Borg) during a 5-km running trial in recreational runners. In a crossover design, eighteen young adult runners (28.7 ± 7.8 years) were randomized to receive 1 of 4 PBMT conditions (placebo, 300, 900, and 1260 Joules [J]) 60min before the 5-km running trial on four occasions, separated by a 2-wk washout period. The treatments were applied to the quadriceps, hamstrings, and gastrocnemius muscles of both legs using a device containing 200 LEDs (100 red and 100 infrared). The following variables were assessed: endurance performance (i.e. total time, mean velocity, and velocity in the split distances at the initial 200m and every 400m lap) and RPE in the split distances at the initial 200m and every 400m lap. Data normality and homogeneity were tested using Shapiro-Wilk's and Levene's tests, respectively. Differences between treatment conditions were assessed using the analysis of variance tests (one- or two-way ANOVA, depending on the comparisons), complemented by the Bonferroni post hoc test. There were significant time effects for the running velocity and RPE in the split distances (p < 0.0001), with no significant treatment-by-time interaction (running velocity, p = 0.59; RPE, p = 0.95). The mean velocity (p = 0.997), total time (p = 0.998), and total mean of the RPE (p = 0.91) were similar between treatment conditions. In conclusion, acute PBMT with LEDs at doses of 300, 900, and 1260J is not recommended for improving endurance performance and RPE in the 5-km running trial in recreational runners.

Test-Retest Reliability of Running Economy and Metabolic and Cardiorespiratory Parameters During a Multistage Incremental Treadmill Test in Male Middle- and Long-Distance Runners.

This study investigated the test-retest reliability of running economy (RE) and metabolic and cardiorespiratory parameters related to endurance running performance using a multistage incremental treadmill test. On two occasions separated by 21-28days, 12 male middle- and long-distance runners ran at 10, 11, 12, 13, and 14km/hr for 8min each stage, immediately followed by a ramp test to volitional exhaustion. Carbohydrate (10% maltodextrin solution) was consumed before and during the test to provide ∼1g/min of exercise. RE, minute ventilation (V˙E), oxygen consumption (V˙O2), carbon dioxide production (V˙CO2), respiratory exchange ratio(RER), heart rate(HR), ratings of perceived exertion(RPE), and blood glucose and lactate concentrations were recorded for each stage and at volitional exhaustion. Time-to-exhaustion (TTE) and peak oxygen consumption (V˙O2peak) during the ramp test were also recorded. Absolute reliability, calculated as the coefficient of variation (CV) between repeated measures, ranged from 2.3% to 3.1% for RE, whereas relative reliability, calculated as the intraclass correlation coefficient(ICC), ranged from .42 to .79. V˙E, V˙O2, V˙O2peak, V˙CO2, RER, and HR had a CV of 1.1%-4.3% across all stages. TTE and RPE had a CV of 7.2% and 2.3%-10.8%, respectively, while glucose and lactate had a CV of 4.0%-17.8%. All otherparameters, except for blood glucose, were demonstrated to have good-to-excellent relative reliability assessed by ICC. Measures of RE, V˙O2peak, and TTE were reliable during this two-phase multistage incremental treadmill test in a cohort of trained and highly trained male middle- and long-distance runners.

Improving hydration in underhydrated, free-living young adults results in better running performance

Dehydration impairs endurance exercise performance, especially in the heat. However, it is unclear how exercise performance is affected by improved hydration status in underhydrated individuals. Therefore, this study examined the impact of a one-week hydration intervention on endurance running performance. We hypothesized better hydration would lead to a faster 2-mile running time. Eighty-nine healthy and moderately fit individuals completed a 2-mile run as fast as possible before (PRE) and after (POST) a 1-week hydration intervention. Performance was incentivized by providing prize money based on ranked average times. First-morning urine samples were collected on the day of each run. If PRE urine specific gravity was &gt;1.020, the subjects were instructed to increase their water intake for one week before the second run. The remaining subjects were instructed to maintain their water intake. All subjects were provided with a filter water bottle. Of the 89 subjects that completed both runs, 44 (18% female, age: 21±2 y, weight: 73.3±12.5 kg, height: 1.76±0.10 m, body mass index: 23.6±3.2 kg/m2) were included in the analysis. Subjects were classified as improved hydration (IMP) if UOsm decreased between PRE and POST by ≥100 mmol/kg and POST was &lt;800 mmol/kg. Subjects were classified as diminished hydration (DIM) if UOsm increased between PRE and POST by ≥100 mmol/kg and POST was &gt;500 mmol/kg. The subjects were removed from the analysis if they met any of the following three conditions: a) had a small UOsm change (&lt;100 mmol/kg) between PRE and POST, b) lowered UOSM but it was still &gt;800 mmol/kg, and c) increased UOsm but it was still &lt;500 mmol/kg. The 2-mile runs took place in Phoenix, Arizona, during the morning (0700 hours) with a maximum ambient temperature of 22±2℃, relative humidity of 37±10%, and WBGT of 16±2℃. UOsm significantly decreased for IMP from PRE: 791±197 to POST: 419±136 mmol/kg (p&lt;0.05) and increased for DIM from PRE: 532±283 to POST: 799±235 mmol/kg (p&lt;0.05). The 2-mile run time significantly improved in IMP from PRE: 13.5±1.8 to POST: 13.3±1.8 min (-11.4±25.8 sec, P=0.03), but did not change in DIM from PRE: 14.2±2.7 to POST: 14.3±2.6 min (+4.8±19.9 sec, P&gt;0.05). The results suggest that improving hydration in underhydrated subjects via one week of increased water intake may improve 2-mile running performance in moderately fit individuals. This study was funded by a grant from the Arizona State University’s Global Sport Institute. Brita donated the filter water bottles. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Acute Effect of Velocity-Based Resistance Training on Subsequent Endurance Running Performance: Volume and Intensity Relevance

This study aimed to compare the acute effect of four back squat velocity-based training (VBT) protocols in terms of intensity (60% vs. 80% of the one repetition maximum [1RM]) and volume (10% vs. 30% threshold for velocity loss in the set) on the maximal aerobic speed (MAS) estimated from a running track test (RTT) in recreationally trained young adult men and women. Twenty participants (eleven men and nine women) undertook five randomized protocols in separate occasions: (i) RTT alone (control condition); (ii) VBT with 60% 1RM and a 10% velocity loss followed by RTT (VBT60–10 + RTT); (iii) VBT with 60% 1RM and a 30% velocity loss followed by RTT (VBT60–30 + RTT); (iv) VBT with 80% 1RM and 10% velocity loss followed by RTT (VBT80–10 + RTT); (v) VBT with 80% 1RM and 30% velocity loss followed by RTT (VBT80–30 + RTT). All VBT protocols involved three sets with three minutes of rest. The MAS was higher for RTT (control) than VBT60–30 + RTT (p &lt; 0.001; Δ = 3.8%), VBT60–10 + RTT (p = 0.006; Δ = 2.8%), VBT80–10 + RTT (p = 0.008; Δ = 2.7%), and VBT80–30 + RTT (p = 0.019; Δ = 1.9%). No protocol × sex interaction was noted (p = 0.422). Therefore, regardless of sex, MAS is acutely impaired after VBT, especially if the training sets are performed with a low relative load and a high velocity loss threshold.

Effects of physical fitness on mental health of Chinese college students: across-sectional study

BackgroundThe physical and mental health of college students is often mentioned, but there is limited research on a direct relationship between the mental health status of college students and their physical fitness level. This study mainly proves the relationship between Chinese college students’ mental health and physical fitness indicators.MethodThis study collected SCL-90 Scale test results from 5262 students (4012 boys and 1250 girls) through a questionnaire survey and conducted a Sport Quality Test on these students. Statistical software SPSS was applied for differential analysis and logistic regression analysis. Specifically, the differences in sport quality indicators between normal and abnormal mean total scores of psychological tests were analyzed first. Then, the binary logistic regression model was used to explore the impacts of sports quality indicator scores on students’ psychological fitness.ResultsThere are differences in the results of physical fitness tests between students with abnormal psychology and students with normal psychology. The four indexes of students’ vital capacity, speed, explosive power of lower limbs, and endurance running are effective in improving students’ psychologically abnormal state, and endurance running and improving vital capacity are the most effective methods to improve students’ psychologically abnormal state. In the physical tests of Chinese college students, the risk of psychological abnormalities was reduced by 9% for every one-point increase in lung capacity and 10.4% for every one-point increase in endurance running performance.ConclusionsChinese college students’ physical fitness and mental health are related. The best methods for treating psychological disorders are lung capacity improvement and endurance running. According to the physical test results of Chinese college students, for every 1-point increase in lung capacity and endurance running, the risk of psychological abnormalities decreased by 9% and 10.4%, respectively.

Comparison between backward, forward, and combined running training on performance of recreationally active young men

The study verified the effects of backward running training (BRT), forward running training (FRT), and combined backward/forward running training (BFRT), prescribed by Vpeak, on performance in 5-km running, countermovement jump, 20-m sprint, and the agility T-test, in thirty-three recreationally active young men. Thirty-three men (age 27.7 ± 4.8 years) were randomly assigned to one of three training groups (BRT; FRT; BFRT) and performed the following tests: 5-km running, vertical jump, 20-m sprint, agility performance, pre- and post-five weeks of running training. The normality of the data was verified by the Shapiro-Wilk test and the comparisons between groups and moments were performed by mixed ANOVA for repeated measures, followed by Bonferroni’s post hoc; the percentage of variation and the effect size (ES) were calculated. A significance level of P &lt; 0.05 was adopted. All groups improved 5-km (P = 0.01) performance at post-training. The Vpeak (P &lt; 0.01) and duration of the incremental test (P &lt; 0.01) increased significantly in all groups after training. The Vpeak_BR increased significantly in the BRT and BFRT groups. CMJ jump height increased significantly for the FRT (P &lt; 0.01) and BFRT (P &lt; 0.05) groups. In the agility T-test there was a significant moment effect (P &lt; 0.01) on the performance time. In conclusion, the inclusion of BRT sessions into FRT, prescribed based on Vpeak_BR and Vpeak_FR, leads to improvements in 5-km endurance running performance in recreationally active young men. Thus, it is suggested that BRT prescribed by Vpeak_BR could be more widely incorporated into FRT as a training method to obtain the same results in endurance performance as FRT alone.

Comparison between backward, forward, and combined running training on performance of recreationally active young men

The study verified the effects of backward running training (BRT), forward running training (FRT), and combined backward/forward running training (BFRT), prescribed by Vpeak, on performance in 5-km running, countermovement jump, 20-m sprint, and the agility T-test, in thirty-three recreationally active young men. Thirty-three men (age 27.7 ± 4.8 years) were randomly assigned to one of three training groups (BRT; FRT; BFRT) and performed the following tests: 5-km running, vertical jump, 20-m sprint, agility performance, pre- and post-five weeks of running training. The normality of the data was verified by the Shapiro-Wilk test and the comparisons between groups and moments were performed by mixed ANOVA for repeated measures, followed by Bonferroni’s post hoc; the percentage of variation and the effect size (ES) were calculated. A significance level of P &lt; 0.05 was adopted. All groups improved 5-km (P = 0.01) performance at post-training. The Vpeak (P &lt; 0.01) and duration of the incremental test (P &lt; 0.01) increased significantly in all groups after training. The Vpeak_BR increased significantly in the BRT and BFRT groups. CMJ jump height increased significantly for the FRT (P &lt; 0.01) and BFRT (P &lt; 0.05) groups. In the agility T-test there was a significant moment effect (P &lt; 0.01) on the performance time. In conclusion, the inclusion of BRT sessions into FRT, prescribed based on Vpeak_BR and Vpeak_FR, leads to improvements in 5-km endurance running performance in recreationally active young men. Thus, it is suggested that BRT prescribed by Vpeak_BR could be more widely incorporated into FRT as a training method to obtain the same results in endurance performance as FRT alone.

Changes in perceived mental fatigue, physical fatigue and mood state during a 4‐day national junior orienteering competition preparation camp

AbstractMental fatigue (MF) has been shown to acutely impair the psychological responses and endurance running performance of orienteers. This study aimed to explore MF levels experienced by orienteers during a 4‐day competition preparation camp that consisted of simulated sprint, middle‐distance, long‐distance, relay and night races. Eleven national junior orienteers participated in the study (age: 15–17 years, height: 1.69 ± 0.07 m and body mass: 59.9 ± 5.22 kg). Subjective ratings of MF, motivation, stress, physical fatigue (PF) and tiredness were measured using a 100‐mm visual analogue scale. The Brunel Mood Scale (BRUMS) was utilized to assess the mood state of the orienteers. The self‐report measures were taken within 30 min of waking, immediately after the post‐training session, and after 24 and 48 h following the final training session. The pre–post orienteering training combined analysis showed that there was a moderate increase in perceived MF (ES = 1.06 [0.66, 1.45]), PF (ES = 1.07 [0.69, 1.45]) and BRUMS fatigue (ES = 0.74 [0.4, 1.1]) after orienteering training. At 48 h post the final training session, MF remained moderately elevated (ES = 0.86 [−0.07, 1.75]), while PF also remained elevated to a small extent (ES = 0.46 [−0.46, 1.39]) compared to the pre‐training values. A moderate impairment was still observed in BRUMS vigor (ES = −1.02 [−1.65, −0.36]), but BRUMS confusion scores were moderately lower (ES = −0.85 [−1.71, 0.04]) than pre‐training values. This study found that orienteering training induced acute MF, persisting for at least 48 h after the final session.

Acute effects of different rest period durations after warm-up and dynamic stretching on endurance running performance in male runners

Acute effects of different rest period durations after warm-up and dynamic stretching on endurance running performance in male runners

Effects of Specific Bioactive Collagen Peptides in Combination with Concurrent Training on Running Performance and Indicators of Endurance Capacity in Men: A Randomized Controlled Trial

BackgroundFirst evidence indicates that the supplementation of specific collagen peptides (SCP) is associated with a significant improvement in running performance in physically active women; however, it is unclear if the same is true in males. The purpose of the present study was to investigate the effects of a concurrent training program including 60 min of continuous moderate intensity running training and 15 min of dynamic resistance training combined with supplementation of SCP on parameters of running performance in moderately trained males.MethodsIn a double-blind, placebo-controlled, randomized trial, participants performed a 12 weeks concurrent training and ingested 15 g of SCP [treatment group (TG)] or placebo [control group (CG)] daily. Before and after the intervention, running endurance performance was measured by a 1-h time trial on a running track. Velocity at the lactate threshold (VLT) and at the individual anaerobic threshold (VIAT) were assessed on a treadmill ergometer. Body composition was evaluated by bioelectrical impedance analysis.ResultsThirty-two men (28.4 ± 5.2 years) completed the study and were included in the analysis. After 12 weeks, TG had a statistically significant (p ≤ 0.05) higher increase in running distance (1727 ± 705 m) compared to the CG (1018 ± 976 m) in the time trial. VLT increased in the TG by 0.680 ± 1.27 km h−1 and slightly decreased by − 0.135 ± 0.978 km h−1 in the CG, resulting in statistically significant group differences (p ≤ 0.05). A significantly higher improvement in VIAT (p ≤ 0.05) was shown in the TG compared with the CG only (1.660 ± 1.022 km h−1 vs 0.606 ± 0.974 km h−1; p ≤ 0.01). Fat mass decreased (TG − 1.7 ± 1.6 kg; CG − 1.2 ± 2.0 kg) and fat free mass increased (TG 0.2 ± 1.2 kg; CG 0.5 ± 1.3 kg) in both groups with no significant group differences.ConclusionIn summary, supplementation with 15 g of SCP improved running performance in a 1-h time trial and enhanced indicators of endurance capacity at submaximal exercise intensities such as an increased velocity at the lactate as well as the anaerobic threshold more effectively than CT alone.Trial registration: ETK: 123/17; DRKS-ID: DRKS00015529 (Registered 07 November 2018—Retrospectively registered); https://drks.de/search/de/trial/DRKS00015529

The effects of exercise-induced muscle damage on varying intensities of endurance running performance: A systematic review and meta-analysis

The effects of exercise-induced muscle damage on varying intensities of endurance running performance: A systematic review and meta-analysis

Acute Ingestion of a Ketone Monoester without Co-ingestion of Carbohydrate Improves Running Economy in Male Endurance Runners.

Acute ingestion of a ketone monoester, with and without co-ingestion of carbohydrate, was investigated for effects on running economy (RE), time to exhaustion (TTE), and other related indices of endurance running performance. Using a three condition, placebo-controlled, randomized crossover design, 11 male middle- and long-distance runners ran at five submaximal speeds (10-14 km·h -1 ) on a motorized treadmill for 8 min each, immediately followed by a ramp test to volitional exhaustion. Participants consumed either a 10% carbohydrate solution (CHO), a 10% carbohydrate solution with 750 mg·kg -1 body mass of an ( R )-3-hydroxybutyl ( R )-3-hydroxybutyrate ketone monoester (CHO + KE), or 750 mg·kg -1 body mass of the ketone monoester in flavored water (KE) before (two-thirds of the dose) and during (one-third of the dose) exercise. β-hydroxybutyrate concentration averaged 1.8 ± 0.3 and 2.1 ± 0.3 mM during exercise in CHO + KE and KE, respectively. RE was lower at each submaximal running speed (effect size = 0.48-0.98) by an average of 4.1% in KE compared with CHO, but not between CHO + KE and CHO. TTE did not differ between CHO (369 ± 116 s), CHO + KE (342 ± 99 s), or KE (333 ± 106 s) ( P = 0.093). Acute ingestion of a ketone monoester without carbohydrate, but not when coingested with carbohydrate, improved RE in middle- and long-distance runners at a range of submaximal running speeds and did not alter TTE in a short-duration ramp test to volitional exhaustion. Further investigation is required to examine if these differences translate into positive performance outcomes over longer durations of exercise.

Apple puree as a natural fructose source provides an effective alternative carbohydrate source for fuelling half-marathon running performance

ABSTRACT Carbohydrate supplementation during endurance exercise is known to improve performance, but the effects of food-based approaches in running exercise are understudied. Therefore, this study investigated the performance and gastrointestinal (GI) effects of a carbohydrate supplement containing a natural fructose source compared with a highly processed fructose source in a combined glucose-fructose supplement, during a half-marathon. Eleven trained runners (9 males, 2 females; age 32 ± 8 y, 89:53 ± 13:28 min half-marathon personal record) completed a familiarisation (8 miles) and two experimental trials (13.1 miles) on an outdoor running course, with blood and urine samples collected before and after the run. Subjective GI measures were made throughout the run. Carbohydrate was provided as a natural fructose source in the form of apple puree (AP) or highly processed crystalline fructose (GF) in a 2:1 glucose-to-fructose ratio (additional required glucose was provided through maltodextrin). Half-marathon performance was not different between carbohydrate sources (AP 89:52 ± 09:33 min, GF 88:44 ± 10:09 min; P = 0.684). There were no interaction effects for GI comfort (P = 0.305) or other GI symptoms (P ≥ 0.211). There were no differences between carbohydrate sources in ad libitum fluid intake (AP 409 ± 206 mL; GF 294 ± 149 mL; P = 0.094) or any other urinary (P ≥ 0.724), blood-based (P ≥ 0.215) or subjective (P ≥ 0.421) measures. Apple puree as a natural fructose source was equivalent to crystalline fructose in supporting half-marathon running performance without increasing GI symptoms. Highlights Research examining food-first and food-based approaches to carbohydrate supplementation and endurance running performance are limited. Therefore, this study aimed to compare carbohydrate supplements either containing a natural or highly processed fructose source as part of a glucose-fructose supplement on half-marathon running performance and gastrointestinal comfort in trained runners. Running performance (apple puree 89:52 ± 09:33 min vs. crystalline fructose 88:44 ± 10:09 min), gastrointestinal comfort and symptoms were not different between the two fructose sources. Apple puree can be effectively used as a carbohydrate source to fuel half-marathon running performance.

Effects of High-Intensity Warm-Up on 5000-Meter Performance Time in Trained Long-Distance Runners.

Warm-up protocols with high intensities before continuous running provide potential benefits for middle-distance runners. Nevertheless, the effect of high-intensity warm-ups on long-distance runners remains unclear. The purpose of this study was to verify the effect of a high-intensity warm-up protocol on 5000 m performance in trained runners. Thirteen male runners (34 ± 10 years, 62 ± 6 kg, 62.7 ± 5.5 ml/kg/min) performed two 5000 m time trials, preceded by two different warm-ups. One high-intensity warm up (HIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (100% of the running intensity) and one low-intensity warm up (LIWU: 1x 500 m (70% of the running intensity) + 3x 250 m (70% of the running intensity)), where the running intensities were calculated using the results obtained in the Cooper test. Physiological and metabolic responses, and endurance running performance parameters, were evaluated by the Counter Movement Jump (CMJ), running rating of perceived exertion (RPE), blood lactate concentration (BLa), and performance running. Total time for the 5000 m was lower using HIWU when compared to LIWU (1141.4 ± 110.4 s vs. 1147.8 ± 111.0 s; p = 0.03; Hedges' g = 0.66). The HIWU warm-up led to an improvement in pacing strategy during the time trial. After warm-up protocols, the performance on the CMJ was improved only when applying HIWU (p = 0.008). Post warm-up BLa was significantly higher for HIWU vs. LIWU (3.5 ± 1.0 mmol·L-1 vs. 2.3 ± 1.0 mmol·L-1; p = 0.02), with similar behavior for the RPE (p = 0.002), internal load of the session (p = 0.03). The study showed that a high-intensity warm-up protocol can improve performance in the 5000 m in trained endurance runners.

Carbohydrate mouth rinse is no more effective than placebo on running endurance of dehydrated and heat acclimated athletes.

To determine whether carbohydrate mouth rinsing would improve endurance running performance of tropical natives in a warm-humid (30°C and 70% relative humidity) environment. Twelve endurance male runners [age 25 ± 3 years; peak aerobic capacity ([Formula: see text]O2peak) 57.6 ± 3.6mL.kg-1.min-1] completed three time-to-exhaustion (TTE) trials at ~ 70% [Formula: see text]O2peak while swilling 25ml of a 6% carbohydrate (CHO) or taste-matched placebo (PLA) as well as no mouth rinse performed in the control (CON) trial. TTE performance was significantly longer in both CHO and PLA trials when compared with the CON trial (54.7 ± 5.4 and 53.6 ± 5.1 vs. 48.4 ± 3.6min, respectively; p < 0.001 and p = 0.012, respectively), but was not significantly different between CHO and PLA trials (p = 1.000). The rating of perceived exertion was not different between the CHO and PLA trials, however, was significantly affected when compared to the CON trial (p < 0.001). A similar effect was observed for perceived arousal level between the CHO and PLA trials to the CON trial. Core temperature, mean skin temperature and skin blood flow were not significantly different between the three trials (all p > 0.05). Similarly, plasma lactate and glucose as well as exercise heart rate were not influenced by the trials. The present study demonstrates that mouth rinsing, whether carbohydrate or placebo, provides an ergogenic benefit to running endurance when compared to CON in a heat stress environment. Nevertheless, the results do not support the notion that rinsing a carbohydrate solution provides a greater advantage as previously described among non-heat acclimated individuals within a temperate condition.

Effects of Caffeine Intake on Endurance Running Performance and Time to Exhaustion: A Systematic Review and Meta-Analysis.

Caffeine (1,3,7-trimethylxanthine) is one of the most widely consumed performance-enhancing substances in sport due to its well-established ergogenic effects. The use of caffeine is more common in aerobic-based sports due to the ample evidence endorsing the benefits of caffeine supplementation on endurance exercise. However, most of this evidence was established with cycling trials in the laboratory, while the effects of the acute intake of caffeine on endurance running performance have not been properly reviewed and meta-analyzed. The purpose of this study was to perform a systematic review and meta-analysis of the existing literature on the effects of caffeine intake on endurance running performance. A systematic review of published studies was performed in four different scientific databases (Medline, Scopus, Web of Science, and SportDiscus) up until 5 October 2022 (with no year restriction applied to the search strategy). The selected studies were crossover experimental trials in which the ingestion of caffeine was compared to a placebo situation in a single- or double-blind randomized manner. The effect of caffeine on endurance running was measured by time to exhaustion or time trials. We assessed the methodological quality of each study using Cochrane's risk-of-bias (RoB 2) tool. A subsequent meta-analysis was performed using the random effects model to calculate the standardized mean difference (SMD) estimated by Hedges' g and 95% confidence intervals (CI). Results: A total of 21 randomized controlled trials were included in the analysis, with caffeine doses ranging between 3 and 9 mg/kg. A total of 21 studies were included in the systematic review, with a total sample of 254 participants (220 men, 19 women and 15 participants with no information about gender; 167 were categorized as recreational and 87 were categorized as trained runners.). The overall methodological quality of studies was rated as unclear-to-low risk of bias. The meta-analysis revealed that the time to exhaustion in running tests was improved with caffeine (g = 0.392; 95% CI = 0.214 to 0.571; p &lt; 0.001, magnitude = medium). Subgroup analysis revealed that caffeine was ergogenic for time to exhaustion trials in both recreational runners (g = 0.469; 95% CI = 0.185 to 0.754; p = 0.001, magnitude = medium) and trained runners (g = 0.344; 95% CI = 0.122 to 0.566; p = 0.002, magnitude = medium). The meta-analysis also showed that the time to complete endurance running time trials was reduced with caffeine in comparison to placebo (g = -0.101; 95% CI = -0.190 to -0.012, p = 0.026, magnitude = small). In summary, caffeine intake showed a meaningful ergogenic effect in increasing the time to exhaustion in running trials and improving performance in running time trials. Hence, caffeine may have utility as an ergogenic aid for endurance running events. More evidence is needed to establish the ergogenic effect of caffeine on endurance running in women or the best dose to maximize the ergogenic benefits of caffeine supplementation.

International orienteering experts’ consensus on the definition, development, cause, impact and methods to reduce mental fatigue in orienteering: A Delphi study

ABSTRACT Orienteering is an outdoor activity wherein participants use a map and compass to locate control points and choose the quickest path to the next control point in a natural environment. Attentional focus, rapid decision-making, and high aerobic fitness may influence orienteering performance. Therefore, this research aimed to seek international orienteering expert consensus regarding the definition, development, causes, influences and methods to reduce mental fatigue (MF) in orienteering based on practical experience. Following ethical approval, a three-round Delphi survey was conducted online with twenty-four orienteering coaches and athletes (or former athletes) from 10 different countries with international orienteering competition experience. The threshold of consensus was ≥ 70% agreement among respondents. The experts agreed that MF exists in daily life and orienteering with a substantial negative effect on their conscious decision-making performance and psychological responses. The experts disagreed that the form of MF that athletes experienced in orienteering training are similar to the competition. However, there was no agreement that MF would impact endurance and high-speed running performance during orienteering. This research refines the definition of MF and summarises the distinctions in what causes MF in orienteering training and competition, implying that MF should be addressed separately.

Daytime fluctuations of endurance performance in young soccer players: a randomized cross-over trial

ObjectivesFluctuations of physical performance and biological responses during a repetitive daily 24-h cycle are known as circadian rhythms. These circadian rhythms can influence the optimal time of day for endurance performance and related parameters which can be crucial in a variety of sports disciplines. The current study aimed to evaluate the daytime variations in endurance running performance in a 3.000-m field run and endurance running performance, blood lactate levels, and heart rate in an incremental treadmill test in adolescent soccer players.ResultsIn this study, 15 adolescent male soccer players (age: 18.0 ± 0.6 years) performed a 3.000-m run and an incremental treadmill test at 7:00–8:00 a.m. and 7:00–8:00 p.m. in a randomized cross-over manner. No significant variations after a Bonferroni correction were evident in endurance running performance, perceived exertion, blood lactate levels, and heart rates between the morning and the evening. Here, the largest effect size was observed for maximal blood lactate concentration (9.15 ± 2.18 mmol/l vs. 10.64 ± 2.30 mmol/l, p = .110, ES = 0.67). Therefore, endurance running performance and physiological responses during a field-based 3.000-m run and a laboratory-based test in young male soccer players indicated no evidence for daytime variations.

Quantitative Evaluation Method of Physical Fitness Factor Indicators in Youth Endurance Running Events

Adolescents are in a critical period of physical and intellectual development, and their growth represents the future of a country. However, with the rapid development of social economy and science and technology, sports and health-related education has not been fully developed, and due to some deviations in the current school curriculum, the physical quality of young people generally declines. Endurance running is a comprehensive index to measure a person’s physical fitness. It reflects the basic motor function of the matrix. It is a must-test item in the physical fitness test of young people. However, the level of endurance running has shown a downward trend in recent years. In the current endurance running training, there are many disadvantages such as extensive training methods, low efficiency, and human errors during detection. In order to improve the performance of endurance running, this paper establishes the index system of endurance running elements by introducing the concept of healthy physical fitness. Based on the elements of endurance running, the article made a detection system and compared it with the standard test method. The data showed that P &lt; 0.001 , indicating that the test results of the two were consistent. The detection system in this paper is suitable for the detection of physical fitness index elements. Then, the endurance running performance of the selected 124 adolescents was combined with the physical fitness index elements, and the correlation was analyzed, indicating that the endurance running level is closely related to the human body shape, cardiopulmonary function, muscle strength, and endurance level. Systematic testing and quantitative results showed that body mass index was significantly correlated with endurance running performance in adolescents ( P &lt; 0.01 ). Also, the number of vertical jumps in place was significantly correlated with the number of sit-ups completed (r= 0.55, P &lt; 0.01 ). This strongly suggests that it is important to quantitatively evaluate the fitness factor indicators of endurance running in adolescents.

Impact of probiotic supplementation on exercise endurance among non-elite athletes: study protocol for a randomized, placebo-controlled, double-blind, clinical trial

BackgroundSome probiotics appear to improve athletic performance, endurance, and recovery after intense exercise. Other formulations may provide performance-related benefits via immune and gastrointestinal functions in athletic individuals. However, few formulations have been studied for both types of effects among non-elite athletes. The primary objective of this study is to assess the ergogenic effects of a probiotic on high-intensity endurance running performance in non-elite runners. Secondary objectives include assessment of perceived exertion, blood chemistry, immune and stress biomarkers, cold and flu symptoms, and gastrointestinal health after the probiotic intervention.MethodsThis 9-week randomized, placebo-controlled, double-blind, parallel trial will assess the ergogenic effects of a probiotic (5 billion colony-forming units/day, for 6 weeks) in healthy, non-elite runners (N=32; 18–45 years). Participants will be monitored via daily and weekly questionnaires during the 2-week pre-baseline, 6-week intervention, and 1-week washout. Questionnaires will inquire about activity, muscle soreness, gastrointestinal symptoms, cold and flu symptoms, stool form and frequency, and adverse events. During the pre-baseline visit, maximal oxygen uptake (V̇O2 max) is assessed to set appropriate individualized workload settings for the treadmill time-to-exhaustion endurance tests. These time-to-exhaustion endurance running tests will be completed at an intensity of 85% VO2max at baseline and final visits. During these tests, self-perceived exercise effort will be rated via the Borg Rating of Perceived Exertion scale and finger sticks assessing capillary blood glucose and lactate concentrations will be collected every 3 min. Additional questionnaires will assess diet and motivation to exercise. Body composition will be assessed using air displacement plethysmography at the baseline and final visits. Hypotheses will be tested using two-sided tests, and a linear model and with a type I error rate of α=0.05. Primary and secondary outcomes will be tested by comparing results between the intervention groups, adjusting for baseline values.DiscussionThese results will build evidence documenting the role of probiotics on running endurance performance and physiological responses to exercise in non-elite athletes. Understanding the potential mechanisms of probiotic effects and how they mitigate the intestinal or immune discomforts caused by running could provide additional strategy means to help runners improve their performance.Trial registration numberClinicalTrials.govNCT04588142. Posted on October 19, 2020.Protocol version: July 2, 2021, version 1.2