Time Trial Performance Research Articles

Effect of Caffeine and Nitrates Combination on Exercise Performance, Heart Rate and Oxygen Uptake: A Systematic Review and Meta-Analysis.

The evidence about the synergy of combining caffeine (CAF) and nitrates on exercise performance has not been summarized, although there is a possibility of additive/synergistic effects of the co-ingestion of these substances given their different mechanisms of action in central (CAF) and peripheral tissues (nitrates). The aim was to analyze the effects of co-supplementation of CAF and nitrates on sports performance in comparison to the isolated ingestion of these substances. The databases of PubMed, Web of Science, Medline, CiNAHL and SPORTDiscus were used until June 2024 following PRISMA guidelines. Randomized controlled trials, at least one single-blind trial, conducted in adults were considered. A meta-analysis was performed using the random effects model to calculate the standardized mean difference estimated by Hedges' g and 95% confidence intervals (CIs) for studies with four arms. Six studies were included (N = 95). The meta-analysis revealed that caffeine and nitrates supplementation (CAF+nitrates) did not enhance performance in time trials (TTs) over the CAF alone (g = -0.06; 95% CI = -0.46 to 0.35; p = 0.78) or nitrates alone (g = 0.29; 95% CI = -0.12 to 0.70; p = 0.17). CAF+nitrates did not affect heart rate during submaximal exercise trials over CAF alone (g = 0.04; 95% CI = -0.31 to 0.40; p = 0.80) or nitrates alone (g = -0.15; 95% CI = -0.50 to 0.20; p = 0.40). Likewise, CAF+nitrates did not affect oxygen uptake during submaximal exercise trials over CAF alone (g = -0.04; 95% CI = -0.45 to 0.37; p = 0.84) or nitrates alone (g = -0.29; 95% CI = -0.70 to 0.12; p = 0.16). CAF+nitrates did not offer further benefits on exercise performance or physiological variables from the isolated intake of CAF and nitrates.

Montmorency cherry supplementation enhances 15km cycling time trial performance: Optimal timing 90-min pre-exercise.

Montmorency cherry (MC) can improve endurance performance, but optimal pre-exercise timing of supplementation and influence of training status on efficacy are unknown. We investigated the effect of MC concentrate ingestion between 30- and 150-min pre-exercise in trained and recreational cyclists on 15-km time trial (TT) performance and exercise economy. Twenty participants (10 recreationally active, RA; 10 trained, T) completed 10min of steady-state exercise (SSE) at 40%Δ (SSE) and a TT on four separate occasions following an unsupplemented (US), 30-, 90- or 150-min pre-exercise Montmorency cherry concentrate (MCC) supplementation conditions (MCC30/90/150min). Venous and capillary blood samples were taken at regular intervals pre- and post-SSE and TT. MCC significantly improved TT performance, but not exercise economy. The greatest improvement in performance occurred following MCC90min compared to US (US 1603.1±248s vs. MCC90min 1554.8±226.7s, 2.83% performance improvement). Performance was significantly enhanced for trained (US 1496.6±173.1s vs. MCC90min 1466.8±157.6s) but not recreationally active participants. Capillary [lactate] and heart rate were significantly greater during the TT for the 90-min dose timing (p<0.05). In the MCC30min and MCC90min conditions, plasma ferulic (US 8.71±3.22nmol. L-1 vs. MCC30min 15.80±8.69nmol. L-1, MCC90min 12.65±4.84nmol. L-1) and vanillic acid (US 25.14±10.91nmol.L-1 vs. MCC30min 153.07±85.91nmol. L-1, MCC90min 164.58±59.06nmol. L-1) were significantly higher pre-exercise than in US and MCC150min conditions (p<0.05). There was no significant change in muscle oxygenation status or plasma nitrite/nitrate concentration. MCC supplementation enhanced endurance exercise performance optimally when consumed ∼90min pre-exercise producing maximal plasma phenolic metabolites during exercise. The ergogenic effect was greater for trained participants.

Changes in respiratory patterns, aerobic capacity, and 40-km time trial performance after 10-week endurance training with voluntarily slowed respiratory rate for cyclists and triathletes

Changes in respiratory patterns, aerobic capacity, and 40-km time trial performance after 10-week endurance training with voluntarily slowed respiratory rate for cyclists and triathletes

Training volume, intensity, and performance of world-class Chinese rowers prior to the 2019 world championships: A case study

Six world-class Chinese male rowers (age: 28.2 ± 3.2 years; height: 1.93 ± 0.02 m; body mass: 94.7 ± 3.9 kg) participated in the study. The training volume in different modalities and intensities were recorded over 44 weeks. To evaluate rowing performance, rowers completed four 2000 m and 5000 m maximum effort time trials and two incremental step tests. Total training time for the season was 907 h, which consisted of 67.5% of rowing training, 16.9% of strength training, 15.2% of warm-up and flexibility, and 0.4% of non-specific endurance training. The rowing training intensity distribution (TID) was 87.0% performed at low intensity (LIT), 8.4% at moderate intensity (MIT), and 4.6% at high intensity (HIT). There was no significant difference in average weekly rowing training volume (distance) at LIT across four phases (p = 0.12), as well as rowing training at MIT (p = 0.07) and HIT (p = 0.97). The fourth 2000 m time trials performance significantly improved from the first trial (−6.4 s, p = 0.02). The fourth 5000 m time trial performance was significantly improved from the first (−13.4 s, p = 0.02) and second trial (−14.1 s, p = 0.01). The final-step mean power output (W) in the second incremental step test improved significantly (p = 0.04). In the 2018–19 season, China's world-class rowers conducted considerable LIT rowing. The training volume distribution and rowing TID were similar in all phases.

Effect of high-dose β-Alanine supplementation on uphill cycling performance in World Tour cyclists: A randomised controlled trial.

Scientists and coaches seek effective ergogenic aids for performance improvement. Cyclists commonly use β-Alanine, which may enhance post-exercise recovery and physical performance. High-dose β-Alanine supplementation's impact on World Tour cyclists during a 7-day camp remains unstudied. This study aimed to analyse the effect of a high dose of β-alanine in World Tour cyclist during a 7-day camp. A double-blinded, randomised controlled trial was conducted. 11 cyclists were included in the final analysis: β-alanine supplementation (n = 5; VO2max: 67.6±1.6 ml/kg/min) and a placebo group (n = 6; VO2max: 68.0±2.4 ml/kg/min). The duration of the supplementation protocol was seven days with four daily intakes. The subjects commenced supplementation after the physical tests (immediately following the snack) and consumed the final intake after breakfast on the day of the final test (a total of 7 days and 3 additional doses, 31 servings in total; 5g per dosage; 155g the total cumulative amount). Before and after seven days of supplementation, the cyclists performed an uphill time trial. Blood lactate, heart rate and rating of perceived exertion were measured during test. β-alanine supplementation improved the relative mean power attained during the time-trial compared with the control group (Z = -2.008; p = 0.045; Δ = 0.060), as well as the time needed to complete this trial (Z = -2.373; p = 0.018). As for physiological and metabolic variables, no significant change was found. In conclusion, the present study supports the effectiveness of one-week high dose of β-alanine during a cycling training in World Tour cyclists to improve their uphill time-trial performance. In addition, it is important to highlight the potential role of β-alanine in improving recovery power. This aspect is particularly relevant in the context of a training camp, where fatigue levels can increase alongside training intensity. Trial registration: This study was registered in ClinicalTrials.gov: (identifier: NCT04427319).

Effect of Low vs. High Carbohydrate Intake after Glycogen-Depleting Workout on Subsequent 1500 m Run Performance in High-Level Runners.

Carbohydrate (CHO) metabolism is crucial for short-duration, high-intensity exercise performance, but the effects of variations in glycogen availability have not been investigated in field trials of trained athletes. This study was designed to test how 1500 m time trial (TT) performance is affected by the manipulation of pre-race glycogen reserves. Competitive middle-distance runners (n = 11 (4 females)) completed a 1500 m individually paced indoor TT after abundant (high, >5 g/kg/d) or restricted (low, <1.5 g/kg/d) dietary CHO intake for 2 days after a glycogen-depleting session. Stride pattern, heart rate (HR), capillary blood lactate, and glucose and plasma malondialdehyde (MDA) response were determined. The TT was slower in low vs. high condition by 4.5 (4.5) s (~2%; p < 0.01), with a tendency toward shorter stride length. Blood lactate and glucose were lower before the TT in low vs. high condition (1.8 (0.5) vs. 2.2 (0.7) mmol/L and 5.4 (0.7) vs. 5.9 (0.8) mmol/L, p = 0.022 and 0.007, respectively), and peak lactate was higher in high vs. low condition (16.8 (3.1) vs. 14.5 (4.2) mmol/L, p = 0.039). Plasma MDA was the same before the TT, and 15 min after the TT, it increased similarly by 15% in low (p = 0.032) and high (p = 0.005) conditions. The restriction of pre-test CHO intake impaired 1500 m TT performance and reduced baseline and peak blood lactate concentrations but not blood glucose or MDA response.

The effect of tart cherry juice compared to a sports drink on cycling exercise performance, substrate metabolism, and recovery.

Tart cherries have low glycemic index, antioxidant and anti-inflammatory properties, and therefore may benefit performance and recovery from exercise. We determined the effects of consuming tart cherry juice versus a high-glycemic index sports drink on cycling performance, substrate oxidation, and recovery of low-frequency fatigue. Using a randomized, counter-balanced cross-over design, with one-month washout, 12 recreational cyclists (8 males and 4 females; 35±16y; VO2peak 38.2±7.4 ml/kg/min) consumed cherry juice or sports drink twice a day (300mL/d) for 4d before and 2d after exercise. On the exercise day, beverages (providing 1g/kg carbohydrate) were consumed 45min before 90min of cycling at 65%VO2peak, followed by a 10km time trial. Blood glucose, lactate, carbohydrate and fat oxidation, respiratory exchange ratio (RER), O2 cost of cycling, and rating of perceived exertion (RPE) were measured during the initial 90min of cycling. Muscle soreness, maximal voluntary contraction (MVC) and low-frequency fatigue were determined at baseline and after the time trial on the exercise day, and 30min after beverage consumption 24 and 48h later. There were no differences for time trial performance (17±3min cherry juice vs. 17±2min sports drink, p = 0.27) or any other measures between drink conditions. There were time main effects (p<0.05) for isometric MVC (decreasing) and low-frequency fatigue (increasing; i.e. decreased force at low relative to high stimulation frequencies), changing significantly from baseline to post-exercise and then returning to baseline at 24h post-exercise. Tart cherry juice was not effective for improving performance, substrate oxidation during exercise, and recovery from exercise, compared to a high-glycemic index sports drink.

The Effects of a Novel Sodium Bicarbonate Ingestion System on Repeated 4km Cycling Time Trial Performance in Well-Trained Male Cyclists.

A novel sodium bicarbonate (SB) product has come to market named the "Bicarb System" (M-SB; Maurten AB, Gothenburg, Sweden). It claims to minimise gastrointestinal (GI) discomfort whilst still improving exercise performance. To investigate the effects of M-SB ingestion on repeated 4km cycling time trials (TT1 and TT2) in well-trained male cyclists. The study recruited ten well-trained cyclists (maximal oxygen uptake ( ): 67 ± 4mlkg-1min-1 BM; peak power output (PPO) at : 423 ± 21 W) to take part in this randomised, crossover and double-blinded study. Following one visit to determine , participants completed a second visit to identify individual time to peak blood bicarbonate (HCO3-) (ITTP) in a rested state. Visit three was a familiarisation trial mimicking the experimental procedures. Visits four to seven consisted of completing 2 × 4km cycling TTs separated by 45min passive recovery, following one of either: 0.3gkg-1 BM M-SB, 0.21gkg-1 BM sodium chloride (placebo; PLA) in vegetarian capsules (size 00), or a control trial (CON). Supplements (M-SB or placebo) were ingested pre-exercise at their respective ITTP. Performance in TT1 was faster in the M-SB condition compared with TT1 in CON (- 5.1s; p = 0.004) and PLA (- 3.5s; p < 0.001). In TT2, performance was also significantly faster in the M-SB condition compared with CON (- 4.4s; p = 0.018) or PLA (- 4.1s; p = 0.002). Total aggregated GI symptoms were generally low and not significantly different between PLA and the M-SB conditions for a range of symptoms. The ingestion of M-SB improves repeated 4km cycling TT performance and the recovery of acid-base balancebetween bouts, whilst causing minimal GI discomfort.

The Impact of Carbohydrate, Protein, and Combined Carbohydrate-Protein Supplementation on Muscle Damage and Oxidative Stress Markers During Prolonged Cycling Performance in the Heat

Background: The impact of oxidative stress (OS) on exercise performance and recovery depends on the mode, intensity, and duration of physical activity, which can lead to inflammation, fatigue, and muscle dysfunction. The effects of carbohydrate (CHO) and protein (PRO) supplementation, as well as their combination (CHO-PRO), on exercise performance remain controversial, particularly under normal and hot environmental conditions. Objectives: The present study examined the influence of locally based isocaloric carbohydrate (CHO) and protein (PRO) supplements on muscle damage and oxidative stress (OS) biomarkers during cycling in the heat (31°C, 70% relative humidity), compared to a placebo (PL). Methods: Sago (Sa), Soy (So), and Sago+Soy (SS) were used as the carbohydrate (CHO), protein (PRO), and CHO-PRO supplements, respectively. The Sa, So, and SS supplements contained 7.5% Sa, 7.5% So, and 6.0% Sa+1.5% So, respectively. Twelve well-trained male cyclists (age: 19.0 ± 5.6 years, height: 170.8 ± 7.6 cm, body weight: 60.1 ± 11.2 kg, and VO2max: 56.5 ± 6.5 mL·kg⁻¹·min⁻¹) participated in four experimental trials. Each trial involved 90 minutes of steady-state cycling on an ergometer at 60% VO2max, followed by a 20-km exhaustive cycling time-trial performance. During the steady-state cycling, participants received supplements five times at 0, 20, 40, 60, and 80 minutes. Results: Plasma concentrations of creatine kinase and F2-isoprostanes, which are biomarkers of muscle damage and oxidative stress (OS), significantly decreased after the trials (P &lt; 0.05). The reduction in these biomarkers in the placebo group indicated that Sa, So, and SS supplementation did not provide additional benefits, as the placebo exhibited similar effects. Conclusions: In conclusion, despite the unexpected results, endurance athletes exercising in hot and humid conditions may potentially reduce symptoms of muscle damage and oxidative stress by consuming greater amounts of carbohydrate and protein supplements.

Assessment of the Omius™ cooling headband effectiveness during a 70-min submaximal running effort followed by a 5-km time-trial in hot/humid conditions

Exercise performed under hot/humid conditions can hinder endurance performance. The Omius™ headband (OH) is purported to reduce the perception of heat and improve performance. We examined the impact of OH on selected thermal and cardiovascular functions, subjective perceptions and running performance. Using a randomized crossover protocol, 10 trained male athletes (28 ± 4 years) completed two trials (OH and sham headband (SH), 35.0 ± 0.3 °C, 56 ± 3% relative humidity) comprising 70 min of running (60% V˙O2max) followed by a 5-km running time-trial (TT). Heart rate, perceived exertion and whole-body thermal comfort did not significantly differ between conditions during the submaximal running effort and TT. Rectal temperature was higher with OH (0.11 ± 0.16 °C, p = 0.052) than SH prior to the submaximal running effort, however, no significant differences were observed between conditions regarding the changes in rectal temperature from baseline during the submaximal running effort and TT. Forehead temperature was significantly lower with OH than SH during the submaximal running effort, but no significant differences were observed at the end of the TT. Scores of perceived forehead thermal comfort were only significantly lower with OH than SH during the submaximal running effort. TT performance did not significantly differ between OH (19.8 ± 1.2 min) and SH (20.2 ± 1.0 min). In conclusion, OH improves forehead thermal comfort and reduces forehead temperature but not rectal temperature, heart rate and perceived exertion during, nor 5-km TT performance following, 70 min of submaximal running in the heat.

Impact of Exercise Heat Acclimation on Performance in Hot, Cool and Hypoxic Conditions

PurposeThe aim of this study was to confirm the impact of heat acclimation on aerobic performance in hot conditions and elucidate the transfer of heat adaptations to cool and hypoxic environments.MethodsTen males (VO2peak: 4.50 ± 0.50 L/min) completed two three-week interventions consisting of heat acclimation (HA: 36°C and 59% RH) and temperate training (TEMP: 18°C and 60% RH) in a counter-balanced crossover design. Training weeks consisted of four work-matched controlled heart rate sessions interspersed with one intermittent sprint session, and two rest days. Before and after the interventions VO2peak and 20-min time trial performance were evaluated in COOL (18°C), HOT (35°C) and hypoxic (HYP: 18°C and FiO2: 15.4%) conditions.ResultsFollowing HA, VO2peak increased significantly in HOT (0.24 L/min [0.01, 0.47], P = 0.040) but not COOL (P = 0.431) or HYP (P = 0.411), whereas TEMP had no influence on VO2peak (P ≥ 0.424). Mean time trial power output increased significantly in HOT (20 W [11, 28], P < 0.001) and COOL (12 W [4, 21], P = 0.004), but not HYP (7 W [−1, 16], P = 0.075) after HA, whereas TEMP had no influence on mean power output (P ≥ 0.110). Rectal (−0.13°C [−0.23, −0.03], P = 0.009) and skin (−0.7°C [−1.2, −0.3], P < 0.001) temperature were lower during the time trial in HOT after HA, whereas mean heart rate did not differ (P = 0.339).ConclusionsHA improved aerobic performance in HOT in conjunction with lower thermal strain and enhanced cardiovascular stability (similar heart rate for higher workload), whereas the mechanistic pathways improving performance in COOL and HYP remain unclear.

The effect of sodium bicarbonate mini-tablets ingested in a carbohydrate hydrogel system on 40km cycling time trial performance and metabolism in trained male cyclists.

Sodium bicarbonate (NaHCO3) ingestion has been found to be ergogenic in high-intensity exercise that ranges from 1 to 10min; however, limited studies have investigated high-intensity exercise beyond this duration. The present study aimed to determine the effect of NaHCO3 ingested using a carbohydrate hydrogel delivery system on 40km time trial (TT) performance in trained male cyclists. Fourteen trained male cyclists ingested 0.3gkg-1 BM NaHCO3 (Maurten AB, Sweden) to determine individualised peak alkalosis, which established time of ingestion prior to exercise. Participants completed a 40km familiarisation TT, and two 40km experimental TTs after ingestion of either NaHCO3 or placebo in a randomised, double-blind, crossover design. NaHCO3 supplementation improved performance (mean improvement = 54.14s ± 18.16s; p = 0.002, g = 0.22) and increased blood buffering capacity prior to (HCO3- mean increase = 5.6 ± 0.2mmolL-1, p < 0.001) and throughout exercise (f = 84.82, p < 0.001, pη2 = 0.87) compared to placebo. There were no differences in total gastrointestinal symptoms (GIS) between conditions either pre- (NaHCO3, 22 AU; Placebo, 44 AU; p = 0.088, r = 0.46) or post-exercise (NaHCO3, 76 AU; Placebo, 63 AU; p = 0.606, r = 0.14). The present study suggests that ingesting NaHCO3 mini-tablets in a carbohydrate hydrogel can enhance 40km TT performance in trained male cyclists, with minimal GIS. This ingestion strategy could therefore be considered by cyclists looking for a performance enhancing ergogenic aid.

Effects of acute beetroot juice intake on performance, maximal oxygen uptake, and ventilatory efficiency in well-trained master rowers: a randomized, double-blinded crossover study.

Beetroot juice (BRJ) intake has been considered a practical nutritional strategy among well-trained athletes. This study aimed to assess the effects of BRJ intake on performance, cardiorespiratory and metabolic variables during a simulated 2000-meter rowing ergometer test in well-trained master rowers. Ten well-trained male master rowers (30-48 years) participated in a randomized, double-blind, crossover design for 3 weeks. In the first week, a researcher explained all the experimental procedures to the participants. In the next two weeks, the participants were tested in 2 rowing ergometer sessions, separated from each other by a 7-day washout period. In both strictly identical sessions, the participants randomly drank BRJ or placebo (PL) 3 hours before the start of the tests. Subsequently, the participants carried out the 2000-meter rowing ergometer tests. Oxygen saturation and blood lactate measurements were performed before starting (pretest) and at the end of the test (posttest). Performance parameters and cardiorespiratory variables were recorded during the rowing ergometer test. An improvement in time trial performance was observed, with a mean difference of 4 seconds (90% confidence limits ± 3.10; p ≤ 0.05) compared to PL. Relative and absolute increased (mean difference of 2.10 mL·kg-1·min-1, 90% confidence limits ± 1.80; mean difference of 0.16 L·min-1 90% confidence limits ± 0.11, respectively; p ≤ 0.05) compared to PL. No ergogenic effect was observed on ventilatory efficiency and blood lactate concentrations after BRJ intake. Acute BRJ intake may improve time trial performance as well as in well-trained master rowers. However, BRJ does not appear to improve ventilatory efficiency.

Trehalose Improved 20-min Cycling Time-Trial Performance After 100-min Cycling in Amateur Cyclists.

Carbohydrate (CHO) supplementation during endurance exercise can improve performance. However, it is unclear whether low glycemic index (GI) CHO leads to differential ergogenic and metabolic effects compared with a standard high GI CHO. This study investigated the ergogenic and metabolic effects of CHO supplementation with distinct GIs, namely, (a)trehalose (30g/hr), (b)isomaltulose (30g/hr), (c)maltodextrin (60g/hr), and (d)placebo (water). In this double-blind, crossover, counterbalanced, placebo-controlled study, 13 male cyclists cycled a total of 100min at varied exercise intensity (i.e.,10-min stages at 1.5, 2.0, and 2.5W/kg; repeated three times plus two 5-min stages at 1.0W/kg before and after the protocol), followed by a 20-min time trial on four separated occasions. Blood glucose and lactate (every 20min), heart rate, and ratings of perceived exertion were collected throughout, and muscle biopsies were taken before and immediately after exercise. The results showed that trehalose improved time-trial performance compared with placebo (total work done 302 ± 39 vs. 287 ± 48kJ; p = .01), with no other differences between sessions (all p ≥ .07). Throughout the 100-min protocol, blood glucose was higher with maltodextrin compared with the other supplements at all time points (all p < .05). Heart rate, ratings of perceived exertion, muscle glycogen content, blood glucose, and lactate were not different between conditions when considering the 20-min time trial (all p > .05). Trehalose supplementation throughout endurance exercise improved cycling performance and appears to be an appropriate CHO source for exercise tasks up to 2hr. No ergogenic superiority between the different types of CHO was established.

Effects of the increase of longitudinal bending stiffness of advanced footwear technology on 3,000m performance, pacing strategy, and biomechanics

This study aimed to analyse the effects of shoes with increased longitudinal bending stiffness (LBS) on 3,000 m performance, pacing strategy, heart rate, and biomechanics in trained runners. Twelve male trained runners performed a 3,000 m time trial test in an experimental shoe with a carbon fibre plate to increase the LBS (LBS-increased) and a Control shoe (without carbon fibre plate). Running performance (total time), pacing, heart rate, and biomechanical variables were registered and analysed for each 1000 m split. An individual analysis of the responders was performed based on the smallest worthwhile change. The 3,000 m time trial performance improved by 0.74% (585.83 ± 33.39 vs. 590.17 ± 34.35 s, p < 0.001, large d = 0.829) in the LBS-increased condition compared to the Control condition with a high inter-individual variability. There were no significant differences for the split effect (p = 0.898, small ηp2 = 0.021). The performance improvement was accompanied by an increase in step length (p < 0.001, large ηp2 = 0.717) throughout the time trial test and an increase of flight time in the split 1 and 2 (p < 0.05, moderate d = 0.793, 0.686, respectively) and vertical oscillation in the split 2 and 3 (p < 0.05, moderate d = 0.727, 0.652). However, the heart rate remained unchanged between conditions. The increase of LBS in footwear can improve 3,000 m performance without causing changes in the pacing strategy. Small modifications in running kinematics accompanied the improvements in running performance but without changes in heart rate. Moreover, LBS-increased did not affect all runners equally highlighting the need for further understanding of individual responses.

Characterization of muscle oxygenation response in well-trained handcyclists.

Peripheral responses might be important in handcycling, given the involvement of smallmusclescompared to other exercise modalities. Therefore, the goal of this study was to compare changes in muscle oxygen saturation (∆SmO2) and deoxyhemoglobin level (∆[HHb]) between different efforts and muscles. Handcyclists participated in a Wingate, a maximal incremental test and a 20-min time-trial (TT). Oxygen uptake (VO2)as well as ∆SmO2, ∆[HHb], deoxygenation and reoxygenation rates in the triceps brachii (TB), biceps brachii (BB), anterior deltoid (AD) and extensor carpi radialis brevis (ER) were measured. ER ∆[HHb]max was 37% greater in the incremental test than in the Wingate (ES = 0.392, P = 0.031). TT mean power (W/kg) was associated with BB ∆SmO2min measured in the incremental test (r = -0.998 [-1.190, -0.806], P = 0.002) and in the Wingate (r = -0.994 [-1.327, -0.661], P = 0.006). MAP (W/kg) was associated with Wingate BB ∆SmO2min (r = -0.983 [-0.999, -0.839], P = 0.003), and Wingate peak (r = 0.649 [0.379, 0.895], P = 0.008) and mean power(W/kg) (r = 0.925 [0.752, 0.972], P = 0.003) was associated with right handgrip force. The strongest physiological predictor for TT performance was BB ∆SmO2min in the incremental test (P = 0.002, r2= 0.993, SEE 0.016W/kg), Wingate BB ∆SmO2min for MAP (P = 0.003, r2= 0.956, SEE 0.058W/kg) and right handgrip force for Wingate peak power (P = 0.005, r2= 0.856, SEE 0.551W/kg). Peripheral aerobic responses (muscle oxygenation) were predictiveof handcycling performance.

An exploration of the deceptive effects of caffeine on morning performance

To compete in evening finals, athletes typically compete in competition heats or quarterfinals in the morning when their bodies are biologically weaker. Performance related qualities that are greater in the evening include force production, power output (~3-14% variation), time-trial performance, and repeated sprints which is ~3 and 5% greater (Drust et al., 2005, Acta Physiol Scand, 183, 181-190). The body clock, motivation and higher core and muscle temperatures in the evening are all related to this daily fluctuation in performance. The most effective nutritional ergogenic for performance is caffeine. The aim of this study was to investigate the effects of deception, a placebo pill vs. No Pill on repeated sprint performance (RSP) and grip strength (GP). The experimental protocol was approved by the institution ethics board. Nine participants ingested 1 pill (maltodextrin) at 06:30 h, entered the laboratory at 07:00 h and had their ear temperature recorded. They then completed a Perceived Onset of Mood questionnaire followed by measures of right- and left-hand grip strength followed by a repeated sprints protocol (10 × 20m, 30 s rest periods). Blood lactate, glucose levels and ear temperature were recorded three times during the protocol – with heart rate, rating of perceived exertion and finishing times (Witty GATE, Microgate Srl, Bolzano, Italy) measured at the end of each sprint. The data was analysed by General Linear modelling with repeated measures.

Effect of caffeine ingestion on time trial performance in cyclists: a systematic review and meta-analysis.

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 Time = -0.55, 95% confidence interval (CI) = -0.84 ~ -0.26, p < 0.01, I2 = 35%; SMD MPO = 0.44, 95% CI = 0.09 ~ 0.79, p < 0.05, I2 = 39%), while the effects of low doses (1-3 mg/kg) of caffeine were not significant (SMD Time = -0.34, 95% CI = -0.84 ~ 0.17, p = 0.19, I2 = 0%; SMD MPO = 0.31, 95% CI = -0.02 ~ 0.65, p = 0.07, I2 = 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.

Astaxanthin Supplementation as a Potential Strategy for Enhancing Mitochondrial Adaptations in the Endurance Athlete: An Invited Review.

Astaxanthin, a potent antioxidant found in marine organisms such as microalgae and krill, may offer ergogenic benefits to endurance athletes. Originally used in fish feed, astaxanthin has shown a greater ability to mitigate various reactive oxygen species and maintain the structural integrity of mitochondria compared to other exogenous antioxidants. More recent work has shown that astaxanthin may improve: (1) cycling time trial performance, (2) cardiorespiratory measures such as submaximal heart rate during running or cycling, (3) recovery from delayed-onset muscle soreness, and (4) endogenous antioxidant capacity such as whole blood glutathione within trained populations. In this review, the history of astaxanthin and its chemical structure are first outlined before briefly describing the various adaptations (e.g., mitochondrial biogenesis, enhanced endogenous antioxidant capacity, etc.) which take place specifically at the mitochondrial level as a result of chronic endurance training. The review then concludes with the potential additive effects that astaxanthin may offer in conjunction with endurance training for the endurance athlete and offers some suggested practical recommendations for athletes and coaches interested in supplementing with astaxanthin.

The Relationship between Inspiratory Muscle Strength and Cycling Performance: Insights from Hypoxia and Inspiratory Muscle Warm-Up.

Hypoxia increases inspiratory muscle work and consequently contributes to a reduction in exercise performance. We evaluate the effects of inspiratory muscle warm-up (IMW) on a 10 km cycling time trial in normoxia (NOR) and hypoxia (HYP). Eight cyclists performed four time trial sessions, two in HYP (FiO2: 0.145) and two in NOR (FiO2: 0.209), of which one was with IMW (set at 40% of maximal inspiratory pressure-MIP) and the other was with the placebo effect (PLA: set at 15% MIP). Time trials were unchanged by IMW (NORIMW: 893.8 ± 31.5 vs. NORPLA: 925.5 ± 51.0 s; HYPIMW: 976.8 ± 34.2 vs. HYPPLA: 1008.3 ± 56.0 s; p > 0.05), while ventilation was higher in HYPIMW (107.7 ± 18.3) than HYPPLA (100.1 ± 18.9 L.min-1; p ≤ 0.05), and SpO2 was lower (HYPIMW: 73 ± 6 vs. HYPPLA: 76 ± 6%; p ≤ 0.05). A post-exercise-induced reduction in inspiratory strength was correlated with exercise elapsed time during IMW sessions (HYPIMW: r = -0.79; p ≤ 0.05; NORIMW: r = -0.70; p ≤ 0.05). IMW did not improve the 10 km time trial performance under normoxia and hypoxia.