Impact of sodium citrate ingestion during recovery after dehydrating exercise on rehydration and subsequent 40-km cycling time-trial performance in the heat

The purpose of this study was to assess the impact of sodium citrate (CIT) ingestion (600 mg·kg−1) during recovery from dehydrating cycling exercise (DE) on subsequent 40-km cycling performance in a warm environment (32 °C). Twenty male nonheat-acclimated endurance athletes exercised in the heat until 4% body mass (BM) loss occurred. After 16 h recovery with consumption of water ad libitum and prescribed diet (evening meal 20 kcal·kg−1, breakfast 12 kcal·kg−1) supplemented in a double-blind, randomized, crossover manner with CIT or placebo (PLC), they performed 40-km time-trial (TT) on a cycle ergometer in a warm environment. During recovery greater increases in BM and plasma volume (PV) concomitant with greater water intake and retention occurred in the CIT trial compared with the PLC trial (p < 0.0001). During TT there was greater water intake and smaller BM loss in the CIT trial than in the PLC trial (p < 0.05) with no between-trial differences (p > 0.05) in sweat loss, PV decrement, ratings of perceived exertion, or TT time (CIT 68.10 ± 3.28 min, PLC 68.11 ± 2.87 min). At the end of TT blood lactate concentration was higher (7.58 ± 2.44 mmol·L−1 vs 5.58 ± 1.32 mmol·L−1; p = 0.0002) and rectal temperature lower (39.54 ± 0.50 °C vs 39.65 ± 0.52 °C; p = 0.033) in the CIT trial than in the PLC trial. Compared with pre-DE time point, PV had decreased to a lower level in the PLC trial than in the CIT trial (p = 0.0001). In conclusion, CIT enhances rehydration after exercise-induced dehydration but has no impact on subsequent 40-km cycling TT performance in a warm uncompensable environment.

Download Full-text

Does caffeine supplementation alter energy contribution during a work-based ~30 min cycling time-trial?

Revista Brasileira de Educação Física e Esporte ◽

10.11606/issn.1981-4690.v34i3p471-481 ◽

2020 ◽

Vol 34 (3) ◽

pp. 471-481

Author(s):

Gabriel Barreto ◽

Rafael Pires da Silva ◽

Guilherme Yamaguchi ◽

Luana Farias de Oliveira ◽

Vitor de Salles Painelli ◽

...

Keyword(s):

Perceived Exertion ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Time Trial ◽

Energy System ◽

Energy Contribution ◽

Mean Power ◽

Double Blind ◽

Cycling Time Trial ◽

Cycling Time

Caffeine has been shown to increase anaerobic energy contribution during short-duration cycling time-trials (TT) though no information exists on whether caffeine alters energy contribution during more prolonged, aerobic type TTs. The aim of this study was to determine the effects of caffeine supplementation on longer and predominantly aerobic exercise. Fifteen recreationally-trained male cyclists (age 38±8 y, height 1.76±0.07 m, body mass 72.9±7.7 kg) performed a ~30 min cycling TT following either 6 mg·kg-1BM caffeine (CAF) or placebo (PLA) supplementation, and one control (CON) session without supplementation, in a double- -blind, randomised, counterbalance and cross-over design. Mean power output (MPO) was recorded as the outcome measure. Respiratory values were measured throughout exercise for the determination of energy system contribution. Data were analysed using mixed-models. CAF improved mean MPO compared to CON (P=0.01), and a trend towards an improvement compared to PLA (P=0.07); there was no difference in MPO at any timepoint throughout the exercise between conditions. There was a main effect of Condition (P=0.04) and Time (P<0.0001) on blood lactate concentration, which tended to be higher in CAF vs. both PLA and CON (Condition effect, both P=0.07). Ratings of perceived exertion increased over time (P<0.0001), with no effect of Condition or interaction (both P>0.05). Glycolytic energy contribution was increased in CAF compared to CON and PLA (both P<0.05), but not aerobic or ATP-CP (both P>0.05). CAF improved aerobic TT performance compared to CON, which could be explained by increased glycolytic energy contribution.

Download Full-text

Does caffeine supplementation alter energy contribution during a work-based ~30 min cycling time-trial?

Revista Brasileira de Educação Física e Esporte ◽

10.11606/1807-5509202000030471 ◽

2020 ◽

Vol 34 (3) ◽

pp. 471-481

Author(s):

Gabriel Barreto ◽

Rafael Pires da Silva ◽

Guilherme Yamaguchi ◽

Luana Farias de Oliveira ◽

Vitor de Salles Painelli ◽

...

Keyword(s):

Perceived Exertion ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Time Trial ◽

Energy System ◽

Energy Contribution ◽

Mean Power ◽

Double Blind ◽

Cycling Time Trial ◽

Cycling Time

Download Full-text

Influence of Caffeine and Sodium Citrate Ingestion on 1,500-m Exercise Performance in Elite Wheelchair Athletes: A Pilot Study

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2013-0127 ◽

2014 ◽

Vol 24 (3) ◽

pp. 296-304 ◽

Cited By ~ 11

Author(s):

Joelle Leonie Flueck ◽

Samuel Mettler ◽

Claudio Perret

Keyword(s):

Exercise Performance ◽

Sodium Citrate ◽

Lactate Concentration ◽

Time Trial ◽

Sodium Concentration ◽

Ergogenic Effect ◽

Double Blind Study ◽

Double Blind ◽

Wheelchair Athletes ◽

National Team

The aim of this study was to investigate whether caffeine and/or sodium citrate have an ergogenic effect on the 1,500-m exercise performance in elite wheelchair athletes. A placebo-controlled, randomized, cross-over and double-blind study design was conducted with the four treatments placebo, caffeine, sodium citrate and the combination of caffeine and sodium citrate. Nine healthy, elite wheelchair-racing athletes (median: [min; max] age: 28 y [23; 54]; height: 173 cm [165; 188]; weight: 62.9 kg [48.9; 68.4], category T53/54) completed the study. All athletes were national team members, including several Paralympic Games, World and European Championship medalists. The athletes performed a 1,500-m time trial four times on a wheelchair training roller. Time to complete 1,500-m, pH, bicarbonate and sodium concentration as well as lactate concentration were measured. The time to complete 1,500-m was not significantly different between the four treatments (placebo: 170.6 s [141.7; 232.0]; caffeine: 179.5 s [134.8; 239.6]; sodium citrate: 178.3 s [136.4; 247.1]; combination: 177.6 s [136.1; 256.2]). However, pH and bicarbonate concentrations were significantly increased with sodium citrate ingestion compared with placebo. Moreover, maximal lactate concentrations were significantly higher in the caffeine and the combination treatment compared with placebo. The supplementation with sodium citrate and/or caffeine did not provide an ergogenic effect on the 1,500-m exercise performance in wheelchair elite athletes.

Download Full-text

The phosphodiesterases type 5 inhibitor tadalafil reduces the activation of the hypothalamus-pituitary-adrenal axis in men during cycle ergometric exercise

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00573.2011 ◽

2012 ◽

Vol 302 (8) ◽

pp. E972-E978 ◽

Cited By ~ 13

Author(s):

Luigi Di Luigi ◽

Paolo Sgrò ◽

Carlo Baldari ◽

Maria Chiara Gallotta ◽

Gian Pietro Emerenziani ◽

...

Keyword(s):

Perceived Exertion ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Double Blind ◽

Phosphodiesterase Type 5 Inhibitors ◽

Adrenal Axis ◽

Free Cortisol ◽

Hypothalamus Pituitary Adrenal Axis ◽

And Performance ◽

Pituitary Adrenal Axis

Phosphodiesterase type 5 inhibitors may influence human physiology, health, and performance by also modulating endocrine pathways. We evaluated the effects of a 2-day tadalafil administration on adenohypophyseal and adrenal hormone adaptation to exercise in humans. Fourteen healthy males were included in a double-blind crossover trial. Each volunteer randomly received two tablets of placebo or tadalafil (20 mg/day with a 36-h interval) before a maximal exercise was performed. After a 2-wk washout, the volunteers were crossed over. Blood samples were collected at −30 and −15 min and immediately before exercise, immediately after, and during recovery (+15, +30, +60, and +90 min) for adrenocorticotropin (ACTH), β-endorphin, growth hormone (GH), prolactin, cortisol (C), corticosterone, dehydroepiandrosterone-sulfate (DHEAS), and cortisol binding globulin (CBG) assays. C-to-CBG (free cortisol index, FCI) and DHEAS-to-C ratios were calculated. Exercise intensity, perceived exertion rate, O2 consumption, and CO2 and blood lactate concentration were evaluated. ACTH, GH, C, corticosterone, and CBG absolute concentrations and/or areas under the curve (AUC) increased after exercise after both placebo and tadalafil. Exercise increased DHEAS only after placebo. Compared with placebo, tadalafil administration reduced the ACTH, C, corticosterone, and FCI responses to exercise and was associated with higher β-endorphin AUC and DHEAS-to-C ratio during recovery, without influencing cardiorespiratory and performance parameters. Tadalafil reduced the activation of the hypothalamus-pituitary-adrenal axis during exercise by probably influencing the brain's nitric oxide- and cGMP-mediated pathways. Further studies are necessary to confirm our results and to identify the involved mechanisms, possible health risks, and potential clinical uses.

Download Full-text

Influence of acetaminophen on performance during time trial cycling

Journal of Applied Physiology ◽

10.1152/japplphysiol.00761.2009 ◽

2010 ◽

Vol 108 (1) ◽

pp. 98-104 ◽

Cited By ~ 61

Author(s):

Alexis R. Mauger ◽

Andrew M. Jones ◽

Craig A. Williams

Keyword(s):

Perceived Exertion ◽

Pain Perception ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Time Trial ◽

Pain Tolerance ◽

Rating Of Perceived Exertion ◽

Significant Difference ◽

Perceived Pain ◽

Condition B

To establish whether acetaminophen improves performance of self-paced exercise through the reduction of perceived pain, 13 trained male cyclists performed a self-paced 10-mile (16.1 km) cycle time trial (TT) following the ingestion of either acetaminophen (ACT) or a placebo (PLA), administered in randomized double-blind design. TT were completed in a significantly faster time ( t12 = 2.55, P < 0.05) under the ACT condition (26 min 15 s ± 1 min 36 s vs. 26 min 45 s ± 2 min 2 s). Power output (PO) was higher during the middle section of the TT in the ACT condition, resulting in a higher mean PO ( P < 0.05) (265 ± 12 vs. 255 ± 15 W). Blood lactate concentration (B[La]) and heart rate (HR) were higher in the ACT condition (B[La] = 6.1 ± 2.9 mmol/l; HR = 87 ± 7%max) than in the PLA condition (B[La] = 5.1 ± 2.6 mmol/l; HR = 84 ± 9%max) ( P < 0.05). No significant difference in rating of perceived exertion (ACT = 15.5 ± 0.2; PLA = 15.7 ± 0.2) or perceived pain (ACT = 5.6 ± 0.2; PLA = 5.5 ± 0.2) ( P > 0.05) was observed. Using acetaminophen, participants cycled at a higher mean PO, with an increased HR and B[La], but without changes in perceived pain or exertion. Consequently, completion time was significantly faster. These findings support the notion that exercise is regulated by pain perception, and increased pain tolerance can improve exercise capacity.

Download Full-text

Mechanisms of Performance Improvements Due to a Leading Teammate During Uphill Cycling

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2017-0878 ◽

2018 ◽

Vol 13 (9) ◽

pp. 1215-1222 ◽

Cited By ~ 1

Author(s):

Theo Ouvrard ◽

Alain Groslambert ◽

Gilles Ravier ◽

Sidney Grosprêtre ◽

Philippe Gimenez ◽

...

Keyword(s):

Heart Rate ◽

Blood Lactate ◽

Perceived Exertion ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Attentional Focus ◽

Rating Of Perceived Exertion ◽

Strong Impact ◽

Competitive Cyclists ◽

The Impact

Purpose: To identify the impact of a leading teammate in front of a cyclist on psychological, physiological, biomechanical, and performance parameters during an uphill maximal effort. Methods: After familiarization, 12 well-trained competitive cyclists completed 2 uphill time trials (UTTs, 2.7 km at 7.4%) in randomized order; that is, 1 performed alone (control condition) and 1 followed a simulated teammate during the entire UTT (leader condition). Performance (UTT time) and mean power output (PO) were recorded for each UTT. For physiological parameters, mean heart rate and postexercise blood lactate concentration were recorded. Psychological parameters (rating of perceived exertion, pleasure, and attentional focus) were collected at the end of each trial. Results: Performance (UTT time) significantly improved by 4.2% (3.1%) in the leader condition, mainly due to drafting decrease of the aerodynamic drag (58% of total performance gains) and higher end spurt (+9.1% [9.1%] of mean PO in the last 10% of the UTT). However, heart rate and postexercise blood lactate concentration were not significantly different between conditions. From a psychological aspect, higher pleasure was observed in the leader condition (+41.1% [51.7%]), but attentional focus was not significantly different. Conclusions: The presence of a leading teammate during uphill cycling had a strong impact on performance, enabling higher speed for the same mean PO and greater end spurt. These results explain why the best teams competing for the general classification of the most prestigious and contested races like the Grand Tours tend to always protect their leader with teammates during decisive ascents.

Download Full-text

Does Sodium-Bicarbonate Ingestion Improve Simulated Judo Performance?

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.17.2.206 ◽

2007 ◽

Vol 17 (2) ◽

pp. 206-217 ◽

Cited By ~ 53

Author(s):

Guilherme Giannini Artioli ◽

Bruno Gualano ◽

Desiré Ferreira Coelho ◽

Fabiana Braga Benatti ◽

Alessandra Whyte Gailey ◽

...

Keyword(s):

Sodium Bicarbonate ◽

Peak Power ◽

Perceived Exertion ◽

Lactate Concentration ◽

Blood Lactate Concentration ◽

Crossover Design ◽

Ratings Of Perceived Exertion ◽

Mean Power ◽

Double Blind ◽

Improved Performance

The aim of the present study was to investigate whether pre exercise sodium-bicarbonate ingestion improves judo-related performance. The study used 2 different protocols to evaluate performance: 3 bouts of a specific judo test (n = 9) and 4 bouts of the Wingate test for upper limbs (n = 14). In both protocols athletes ingested 0.3 g/kg of sodium bicarbonate or placebo 2 h before the tests. Blood samples were collected to determine lactate level, and levels of perceived exertion were measured throughout the trials. The study used a double-blind, counterbalanced, crossover design. Ingestion of sodium bicarbonate improved performance in Bouts 2 and 3 of Protocol 1 (P < 0.05), mean power in Bouts 3 and 4 of Protocol 2 (P < 0.05), and peak power in Bout 4 of Protocol 2 (P < 0.05). Ingestion of bicarbonate increased lactate concentration in Protocol 1 (P < 0.05) but not in Protocol 2. Ratings of perceived exertion did not differ between treatments. In conclusion, sodium bicarbonate improves judo-related performance and increases blood lactate concentration but has no effect on perceived exertion.

Download Full-text

The Effect of Siberian Ginseng (Eleutherococcus Senticosus) on Substrate Utilization and Performance during Prolonged Cycling

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.10.4.444 ◽

2000 ◽

Vol 10 (4) ◽

pp. 444-451 ◽

Cited By ~ 10

Author(s):

L. Christopher Eschbach ◽

Michael J. Webster ◽

Joseph C. Boyd ◽

Patrick D. McArthur ◽

Tammy K. Evetovich

Keyword(s):

Steady State ◽

Perceived Exertion ◽

Time Trial ◽

Cycling Performance ◽

Substrate Utilization ◽

Rating Of Perceived Exertion ◽

Time Interval ◽

Double Blind ◽

Eleutherococcus Senticosus ◽

Siberian Ginseng

It has been suggested that Eleutherococcus senticosus (ES). also known as Siberian ginseng or ciwuija. increases fat utilization in humans. The purpose of this study was to examine the physiological responses to supplementation with ES in endurance cyclists. Using arandomized. double-blind crossover design. 9 highly-trained men (28 ± 2 years. V̇O2max 57.3±2.0 ml · kg−1 · min−1) cycled for 120 min at 60% V̇O2max followed by a simulated 10-km lime trial. Diet was controlled, and ES (1,200 mg · day−1) or a placebo (P) were administered for 7 days prior to each of the two trials. Oxygen consumption, respiratory exchange ratio, and heart rate were recorded every 30 min, and rating of perceived exertion. plasma [lactate], and plasma [glucose j were recorded every 20 min during the 120 min of steady state cycling. There were no significant differences (p > .05) between the ES and P groups at any steady-state time interval or during the cycling time trial (ES = 18.10 ± 0.42, P = 17.83 ± 0.47 min). In contrast with previous reports, the results of this study suggest that ES supplementation does not alter steady-state substrate utilization or 10-km cycling performance time.

Download Full-text

Physiological Profile of an Uphill Time Trial in Elite Cyclists

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2016-0768 ◽

2018 ◽

Vol 13 (3) ◽

pp. 268-273 ◽

Cited By ~ 3

Author(s):

Ana B. Peinado ◽

Nuria Romero-Parra ◽

Miguel A. Rojo-Tirado ◽

Rocío Cupeiro ◽

Javier Butragueño ◽

...

Keyword(s):

Power Output ◽

Perceived Exertion ◽

Lactate Concentration ◽

Time Trial ◽

Cycling Performance ◽

Mean Power ◽

Road Cycling ◽

And Performance ◽

Mean Power Output ◽

Elite Cyclists

Context: While a number of studies have researched road-cycling performance, few have attempted to investigate the physiological response in field conditions. Purpose: To describe the physiological and performance profile of an uphill time trial (TT) frequently used in cycling competitions. Methods: Fourteen elite road cyclists (mean ± SD age 25 ± 6 y, height 174 ± 4.2 cm, body mass 64.4 ± 6.1 kg, fat mass 7.48% ± 2.82%) performed a graded exercise test to exhaustion to determine maximal parameters. They then completed a field-based uphill TT in a 9.2-km first-category mountain pass with a 7.1% slope. Oxygen uptake (VO2), power output, heart rate (HR), lactate concentration, and perceived-exertion variables were measured throughout the field-based test. Results: During the uphill TT, mean power output and velocity were 302 ± 7 W (4.2 ± 0.1 W/kg) and 18.7 ± 1.6 km/h, respectively. Mean VO2 and HR were 61.6 ± 2.0 mL · kg−1 · min−1 and 178 ± 2 beats/min, respectively. Values were significantly affected by the 1st, 2nd, 6th, and final kilometers (P < .05). Lactate concentration and perceived exertion were 10.87 ± 1.12 mmol/L and 19.1 ± 0.1, respectively, at the end of the test, being significantly different from baseline measures. Conclusion: The studied uphill TT is performed at 90% of maximum HR and VO2 and 70% of maximum power output. To the authors’ knowledge, this is the first study assessing cardiorespiratory parameters combined with measures of performance, perceived exertion, and biochemical variables during a field-based uphill TT in elite cyclists.

Download Full-text

Mitochondria-targeted antioxidant supplementation improves 8 km time trial performance in middle-aged trained male cyclists

10.21203/rs.3.rs-69222/v1 ◽

2020 ◽

Author(s):

Sophie Broome ◽

Andrea Braakhuis ◽

Cameron Mitchell ◽

Troy Merry

Keyword(s):

Perceived Exertion ◽

Average Power ◽

Time Trial ◽

Cycling Performance ◽

Middle Aged ◽

Clinical Trial Registry ◽

Double Blind ◽

Nutritional Strategy ◽

Exercise Induced ◽

Respiratory Gases

Abstract BackgroundExercise increases skeletal muscle ROS production, which may contribute to the onset of muscular fatigue and impair athletic performance. Mitochondria-targeted antioxidants such as MitoQ are becoming popular amongst active individuals as they are designed to accumulate within mitochondria and may provide targeted protection against exercise-induced oxidative stress. However, the effect of MitoQ supplementation on cycling performance is currently unknown. Here we investigate whether MitoQ supplementation can improve cycling performance measured as time to complete an 8 km time trial.MethodIn a randomised, double-blind, placebo-controlled crossover study, 19 middle-aged (age: 44 ± 4 years) recreationally trained (VO2peak: 58.5 ± 6.2 ml·kg·min− 1, distance cycled per week during six months prior to study enrollment: 158.3 ± 58.4 km) male cyclists completed 45 min cycling at 70% VO2peak followed by an 8 km time trial after 28 days of supplementation with MitoQ (20 mg/day) and a placebo. Free F2-isoprostanes were measured in plasma samples collected at rest, after 45 min cycling at 70% VO2peak and after completion of the time trial. Respiratory gases and measures of rate of perceived exertion (RPE) were also collected.ResultsMean completion time for the time trial was 1.3% faster with MitoQ (12.91 ± 0.94 min) compared to placebo (13.09 ± 0.95 min, P = 0.04 95% CI [0.05, 2.64], d = 0.2). There was no difference in RPE during the time trial between conditions (P = 0.82) despite average power output during the time trial being higher following MitoQ supplementation (280 ± 53 W) compared to placebo (270 ± 51 W, P = 0.04). Plasma F2-isoprostanes were lower on completion of the time trial following MitoQ supplementation (35.89 ± 13.6 pg/ml) compared to placebo (44.7 ± 16.9 pg/ml P = 0.03).ConclusionThese data suggest that MitoQ supplementation may be an effective nutritional strategy to attenuate exercise-induced increases in oxidative damage to lipids and improve cycling performance.Trial registrationThis study was registered with the Australia New Zealand Clinical Trial Registry (ACTRN12619000451101) on 19th March 2019.

Download Full-text