Explore the vast range of titles available.

It has been assumed that exercise intensity variation throughout a cycling time trial (TT) occurs in alignment of various metabolic changes to prevent premature task failure. However, this assumption is based on target metabolite responses, which limits our understanding of the complex interconnection of metabolic responses during exercise. The current study characterized the metabolomic profile, an untargeted metabolic analysis, after specific phases of a cycling 4‐km TT. Eleven male cyclists performed three separated TTs in a crossover counterbalanced design, which were interrupted at the end of the fast‐start (FS, 600 ± 205 m), even‐pace (EP, 3600 ± 190 m), or end‐spurt (ES, 4000 m) phases. Blood samples were taken before any exercise and 5 min after exercise cessation, and the metabolomic profile characterization was performed using Nuclear Magnetic Resonance metabolomics. Power output (PO) was also continually recorded. There were higher PO values during the FS and ES compared to the EP (all p < 0.05), which were accompanied by distinct metabolomic profiles. FS showed high metabolite expression in TCA cycle and its related pathways (e.g., glutamate, citric acid, and valine metabolism); whereas, the EP elicited changes associated with antioxidant effects and oxygen delivery adjustment. Finally, ES was related to pathways involved in NAD turnover and serotonin metabolism. These findings suggest that the specific phases of a cycling TT are accompanied by distinct metabolomic profiles, providing novel insights regarding the relevance of specific metabolic pathways on the process of exercise intensity regulation. Highlights Untargeted metabolomic profile analysis may reveal unexplored bioenergetic pathways activated throughout a self‐paced cycling time trial. Exercise intensity variations throughout a cycling time trial are accompanied by different blood serum metabolomic profiles. The current new insights may encourage future investigation on the underpinning mechanisms of specific metabolomic profiles according to each time trial phase.

This study examined the effect of time of day (TOD) on physical performance, and physiological and perceptual responses to a 10-km cycling time trial (TT ). Twelve physically trained subjects (20.3 ± 1.2 years, 74.3 ± 7.4 kg, 179.7 ± 5.5 cm) completed, in a randomized order, a TT in the morning and in the evening. Intra-aural temperature (IAT) was measured at rest and following the TT . Completion time, power output (PO), rating of perceived exertion (RPE), heart rate (HR), minute ventilation (V̇E), oxygen uptake (V̇O ), carbon dioxide production (V̇CO ) and respiratory exchange ratio (RER) were assessed every km during the TT . Blood lactate concentration [La] and blood glucose concentration [Glu] were assessed before, during and immediately after the TT . Faster completion time (Δ = 15.0s, p = 0.03) and higher IAT (Δ = 0.33°C, p = 0.02 for pre-TT ) were obtained in the evening compared to the morning with a significant correlation between Δ completion time and Δ IAT at post-TT (r = -0.83, p = 0.04). V̇O , [La] and [Glu] increased significantly during both test sessions (p < 0.001) with higher values in the evening compared to the morning (p = 0.015, p = 0.04, p = 0.01, respectively). However, the remaining parameters were found to be only affected by the TT (p < 0.001). The TT generates a higher V̇O and higher [La] and [Glu] responses, contributing to a better cycling performance in the evening compared to the morning. The similar magnitude of the TOD effect on completion time and IAT at post-TT confirms that core temperature is one of the underlying factors contributing to the diurnal variation in physical performance.

It is understood that withholding information during exercise can alter performance during self‐paced exercise, though less is known about neural activity during such exercise. The aim of this study was to compare the effects of withholding versus providing distance feedback on perception, muscular activation, and cerebral activity during cycling time trials (TT). Nine well‐trained male cyclists randomly completed 2 x 30‐km TT, with provision of performance information and distance feedback (known; KTT), and without performance information and remaining distance (unknown; UTT). Prefrontal cortex (PFC) hemoglobin concentration, electroencephalogy (EEG) responses of the parietal lobe (PL) and motor cortex (MC), and surface electromyogram (EMG) of the right thigh were monitored throughout the TTs, in addition to heart rate (HR), rating of perceived exertion (RPE), and power output (PO). Time to completion was shorter for the KTT compared to UTT (51.04 ± 3.26 vs. 49.25 ± 3.57 min, P = 0.01). There were no differences evident for RPE between conditions (P > 0.50). However, during the final 2 km, the KTT presented higher PO (P ≤ 0.05), HR (P = 0.03) and MC, and PL EEG activity (d = 0.51–0.71) in addition to increased tissue hemoglobin index (nTHI) and oxygen extraction (HHb) (d = 0.55‐0.65) compared to the UTT. In conclusion, when withholding information pertaining to remaining distance, performance was reduced due to the application of a conservative pacing strategy. In addition, the increase in HHb across the PFC was strongly correlated with PO (r = 0.790; P < 0.001) suggesting knowledge about remaining distance may increase activation across the PFC. Further, it appears that changes within the PFC may play a role in the regulation of cycling performance. It is understood that withholding information pertaining to remaining duration during an exercise bout can alter performance during self‐paced efforts, however, less is known about neural activity during such exercise. The aim of this study was to compare the effects of withholding versus providing distance feedback on perception, muscular activation, and cerebral activity including electroencephalogram and cerebral oxygenation during 30‐km cycling time trials (TT). The findings of this study suggest that knowledge about remaining distance may increase activation across the prefrontal cortex, which may be related to the central regulation of cycling performance.

Caffeine, widely recognized as an ergogenic aid, has undergone extensive research, demonstrating its effectiveness to enhance endurance performance. However, there remains a significant gap in systematically evaluating its effects on time trial (TT) performance in cyclists. This meta-analysis aimed to determine the efficacy of caffeine ingestion to increase cycling TT performance in cyclists and to evaluate the optimal dosage range for maximum effect. A search of four databases was completed on 1 December 2023. The selected studies comprised crossover, placebo-controlled investigations into the effects of caffeine ingestion on cycling TT performance. Completion time (Time) and mean power output (MPO) were used as performance measures for TT. Meta-analyses were performed using a random-effects model to assess the standardized mean differences (SMD) in individual studies. Fifteen studies met the inclusion criteria for the meta-analyses. Subgroup analysis showed that moderate doses of caffeine intake (4-6 mg/kg) significantly improved cycling performance (SMD  = -0.55, 95% confidence interval (CI) = -0.84 ~ -0.26,  < 0.01,  = 35%; SMD  = 0.44, 95% CI = 0.09 ~ 0.79,  < 0.05,  = 39%), while the effects of low doses (1-3 mg/kg) of caffeine were not significant (SMD  = -0.34, 95% CI = -0.84 ~ 0.17,  = 0.19,  = 0%; SMD  = 0.31, 95% CI = -0.02 ~ 0.65,  = 0.07,  = 0%). A moderate dosage (4-6 mg/kg) of caffeine, identified as the optimal dose range, can significantly improve the time trial performance of cyclists, while a low dose (1-3 mg/kg) does not yield improvement. In addition, the improvements in completion time and mean power output resulting from a moderate dose of caffeine are essentially the same in cycling time trails.

To examine the effect of pre-cooling (PreC) on cycling time-trial (CTT) performance in heat, before and after heat acclimation (HA). Randomised crossover. Ten trained/highly trained male cyclists and/or triathletes completed two 20-km CTT before (PreHA) HA training sessions (10 × 60 min intermittent-heat exposure protocol in 36 °C, 50–80 % relative humidity), and after (PostHA). No cooling (CON) or crushed-ice was ingested (i.e., PreC) 30 min prior to the CTTs. The first and final HA training sessions were matched and acted as heat stress tests for comparison. No meaningful direct relations were observed for 20-km CTT completion time between PostHA+PreC (2663 ± 307 s) and PostHA-CON (2671 ± 370 s; b = 37.81 [−109.98, 170.56]). Split times were faster in the first 12.5 km of the CTT in PostHA+PreC but slower across the rest of the CTT compared to PostHA-CON (b = −1.224 [−2.196, −0.157]). Core temperature was lower in PostHA-CON compared to PostHA+PreC (b = −0.02 [−0.04, −0.01]). No difference was observed for mean skin temperature (b = −0.16 [−0.27, −0.05]) and thermal sensation (b = −0.047 [−0.091, −0.003]) during the CTT. Insufficient evidence exists to support a meaningful performance improvement in 20-km CTT in hot-humid conditions when PreC was applied to individuals who completed an HA regime. This may be attributed to the limited effect of PreC on thermal perception, potentially leading to decreased exercise intensity in the latter stages of the CTT as a strategy to mitigate heat gain. Additionally, sub-optimal pacing strategies resulting from PreC on individuals may explain the lack of additional benefit to performance.

Caffeine is a well-established ergogenic aid for endurance performance. However, the optimal intake strategy, specifically the administration method and dosage, remains uncertain. This systematic review and network meta-analysis compared the effectiveness of different caffeine administration methods and dosages on time-trial performance. A systematic review and network meta-analysis were conducted following PRISMA guidelines. A systematic search of PubMed, Embase, Web of Science, Scopus, and SPORTDiscus was conducted up to July 2025. Eligible studies were independently screened and quality-assessed by two reviewers. Pairwise and network meta-analyses were conducted to examine the effects of caffeine administration methods (e.g., capsules/tablets, gum, mouth rinse) and dosages (low: ≤3 mg/kg; moderate: 4-6 mg/kg) on time-trial performance. Forty-eight studies with 612 participants were included. Low-dose capsules most effectively reduced completion time (standardized mean differences [SMD] = -0.34; 95% confidence interval [CI] -0.62, -0.06), followed by moderate-dose capsules (SMD = -0.31; 95% CI: -0.45, -0.17) and moderate-dose gum (SMD = -0.30; 95% CI: -0.57, -0.02). Low-dose capsules also had the highest probability of improving mean power output (SMD = 0.38; 95% CI: 0.09, 0.67), with moderate-dose capsules ranking second (SMD = 0.30; 95% CI: 0.12, 0.48). This systematic review and network meta-analysis identified low-dose caffeine capsules (≈3 mg/kg) as the most effective strategy for improving time-trial performance, with moderate-dose capsules and gum serving as viable alternatives. While these findings provide robust, actionable evidence for practitioners, meaningful inter-individual variability persists. Accordingly, future studies should integrate deeper mechanistic profiling (e.g., genetics and body composition) to advance personalized, evidence-based caffeine supplementation for athletes.

Purpose To compare the effects of self-paced high-intensity interval and continuous cycle training on health markers in premenopausal women. Methods Forty-five inactive females were randomised to a high-intensity interval training (HIIT; n  = 15), continuous training (CT; n  = 15) or an inactive control (CON; n  = 15) group. HIIT performed 5 × 5 min sets comprising repetitions of 30-s low-, 20-s moderate- and 10-s high-intensity cycling with 2 min rest between sets. CT completed 50 min of continuous cycling. Training was completed self-paced, 3 times weekly for 12 weeks. Results Peak oxygen uptake (16 ± 8 and 21 ± 12%), resting heart rate (HR) (−5 ± 9 and −4 ± 7 bpm) and visual and verbal learning improved following HIIT and CT compared to CON ( P  < 0.05). Total body mass (−0.7 ± 1.4 kg), submaximal walking HR (−3 ± 4 bpm) and verbal memory were enhanced following HIIT ( P  < 0.05), whereas mental well-being, systolic (−5 ± 6 mmHg) and mean arterial (−3 ± 5 mmHg) blood pressures were improved following CT ( P  < 0.05). Participants reported similar levels of enjoyment following HIIT and CT, and there were no changes in fasting serum lipids, fasting blood [glucose] or [glucose] during an oral glucose tolerance test following either HIIT or CT ( P  > 0.05). No outcome variable changed in the CON group ( P  > 0.05). Conclusions Twelve weeks of self-paced HIIT and CT were similarly effective at improving cardiorespiratory fitness, resting HR and cognitive function in inactive premenopausal women, whereas blood pressure, submaximal HR, well-being and body mass adaptations were training-type-specific. Both training methods improved established health markers, but the adaptations to HIIT were evoked for a lower time commitment.

ObjectiveThis study aimed to verify the acute and prolonged effects of stretch–shortening cycle exercise (SSC) on performance and neuromuscular function following a 4-km cycling time trial (4-km TT).MethodsOn separate days, individuals performed a 4-km TT without any previous exercise (CON), immediately (ACUTE) and 48 h after (PROL) SSC protocol (i.e., 100-drop jumps). Neuromuscular function was measured at baseline SSC (baseline), before (pre-TT) and after (post-TT) 4-km TT. Muscle soreness and inflammatory responses also were assessed.ResultsThe endurance performance was impaired in both ACUTE (− 2.3 ± 1.8%) and PROL (− 1.8 ± 2.4%) compared with CON. The SSC protocol caused also an acute reduction in neuromuscular function, with a greater decrease in potentiated quadriceps twitch-force (Qtw.pot − 49 ± 16%) and voluntary activation (VA − 6.5 ± 7%) compared for CON and PROL at pre-TT. The neuromuscular function was fully recovered 48 h after SSC protocol. Muscle soreness and IL-10 were elevated only 48 h after SSC protocol. At post-TT, Qtw.pot remained lower in ACUTE (− 52 ± 14%) compared to CON (− 29 ± 7%) and PROL (− 31 ± 16%).ConclusionThese findings demonstrate that impairment in endurance performance induced by prior SSC protocol was mediated by two distinct mechanisms, where the acute impairment was related to an exacerbated degree of peripheral and central fatigue, and the prolonged impairment was due to elevated perceived muscle soreness.

To determine the effects of heat stress on ankle proprioception and running gait pattern. Counterbalanced repeated measures. 12 trained runners performed a proprioception test (active movement discrimination) before and immediately after a 30min, self-paced treadmill run in HOT (39°C) and COOL (22°C) ambient conditions. Velocity was imposed during the first and last minute (70% of maximal aerobic velocity, 13.3±0.8kmh−1) for determination of running mechanics and spring–mass characteristics. Rectal (39.7±0.4 vs. 39.4±0.4°C), skin (36.3±1.1 vs. 31.8±1.1°C) and average body (38.3±0.2 vs. 36.4±0.4°C) temperatures together with heart rate (178±8 vs. 174±6bpm) and thermal discomfort (6.5±0.5 vs. 4.3±1.3) were all higher at the end of the HOT compared to COOL run (all p<0.05). Distance covered was lower in HOT than COOL (−5.1±3.6%, p<0.001). Average error during the proprioception test increased after running in HOT (+11%, p<0.05) but not in COOL (−2%). There was no significant difference for most segmental and joint angles at heel contact, except for a global increase in pelvis retroversion and decrease in ankle dorsi-flexion angles with time (p<0.05). Step frequency decreased (−2.5±3.6%) and step length increased (+2.6±3.8%) over time (p<0.05), independently of condition. Spring–mass characteristics remained unchanged (all p>0.05). Heat stress exacerbates thermal, cardiovascular and perceptual responses, while running velocity was slower during a 30min self-paced treadmill run. Heat stress also impairs ankle proprioception during an active movement discrimination task, but it has no influence on gait pattern assessed at a constant, sub-maximal velocity.

Purpose The purpose of the study was to investigate the acute effect of a beginner martial art class and aerobic exercise on executive function (EF) in college-aged young adults. There is overwhelming evidence that demonstrates acute as well as long-term aerobic exercise improves EF. Nevertheless, there is limited research comparing externally paced exercise (EPE) to self-paced exercise (SPE) such as walking on improving EF. EPE requires greater cortical demand than SPE to execute a motor plan. Methods Eight men and eight women, aged 24.2 ± 2.8 years, participated in a Repeated Measures Crossover Design. Pre- and post-testing of EF with the Stroop and Tower of London (ToL) and stress level were measured after each of the two 1-h conditions: the SPE consisted of a walk (aerobic exercise) and the EPE was a beginner martial art class. Results There were significant main effects for the martial art class for the Stroop’s mean reaction time for congruent trials ( P  = 0.01) with a large-effect size. The mean reaction time for incongruent trials was significant ( P  = 0.05) with a medium-effect size. The ToL’s mean solution time ( P  = 0.003) and mean execution time ( P  = 0.002) were also significant with large-effect sizes. Stress levels were not significantly improved following either condition. Conclusion The martial art class significantly improved all the major domains of EF, while aerobic exercise of a similar intensity did not demonstrate any measured significant changes. The physiological benefits of physical exercise are well documented; however, the cognitive enhancing capability of EPE should also be appreciated given the results of this study.