scholarly journals Caffeine, exercise physiology, and time-trial performance: no effect of ADORA2A or CYP1A2 genotypes

Author(s):  
Mark Glaister ◽  
Kiran Chopra ◽  
Ana Pereira De Sena ◽  
Cassie Sternbach ◽  
Liridon Morina ◽  
...  

The aim of this study was to investigate the influence of ADORA2A and CYP1A2 genotypes on the physiological and ergogenic effects of caffeine. Sixty-six male cyclists were screened for ADORA2A and CYP1A2 genotypes; with 40 taking part subsequently in a randomised, double-blind, placebo-controlled study. Trial 1 was used to establish the V̇O2-power output relationship and V̇O2max. In trials 2 and 3, participants ingested 5 mg·kg-1 of caffeine or placebo one hour before completing a submaximal incremental cycling test, followed by a time-trial (~ 30 mins). Relative to placebo, caffeine led to a significant reduction in time to complete the time-trial (caffeine: 29.7 ± 1.8 mins; placebo: 30.8 ± 2.3 mins); but there was no effect of genotype. During submaximal exercise, caffeine reduced mean heart rate by 2.9 ± 3.7 b·min-1, with effects dissipating as exercise intensity increased. Caffeine also significantly reduced perceived exertion by 0.5 ± 0.8, and increased blood lactate by 0.29 ± 0.42 mmol·L-1, respiratory exchange ratio by 0.013 ± 0.032, and minute ventilation by 3.1 ± 6.8 L·min-1. Nonetheless, there were no supplement × genotype interactions. In conclusion, caffeine influences physiological responses to submaximal exercise and improves time-trial performance irrespective of ADORA2A or CYP1A2 genotypes. Novelty •Caffeine affects physiological responses at rest and during submaximal exercise independent of ADORA2A or CYP1A2 genotypes. •Variability in the effect of caffeine on time-trial performance is not explained by ADORA2A or CYP1A2 genotypes.

2020 ◽  
Author(s):  
Ana Elisa von Ah Morano ◽  
Camila S. Padilha ◽  
Vinicius Aparecido Matos Soares ◽  
Fabiana Andrade Machado ◽  
Peter Hofmann ◽  
...  

Abstract Background: To investigate the acute effect of capsaicin analog supplementation on 10-km time-trial running performance and physiological responses in amateur athletes. Methods: Twenty-one participants (age = 29.3 ± 5.5 years), completed two randomized, double-blind trials: capsaicin analog condition [Capsiate (CAP) = 24 mg] or a placebo condition. The participants consumed two doses of 12 mg of capsaicin or placebo capsule 45 minutes before and immediately at the start of each trial. The time required to complete 10-km in minutes, lactate concentration, maximum heart rate (HR), and rating of perceived exertion (RPE) were recorded. Results: 10-km time-trial performance (CAP= 44.4 ± 6.3 min vs placebo= 45.3 ± 6.8 min, P = 0.823) was not statistically significant different between conditions. No statistically significant differences between conditions were detected for lactate concentration (P = 0.507), HR (P = 0.897) and RPE (P = 0.517). Conclusion: Capsaicin analog supplementation did not improve performance and physiological responses in a 10-km running time-trial in amateur athletes.


2020 ◽  
Author(s):  
Ana Elisa von Ah Morano ◽  
Camila S. Padilha ◽  
Vinicius Aparecido Matos Soares ◽  
Fabiana Andrade Machado ◽  
Peter Hofmann ◽  
...  

Abstract Background: To investigate the acute effects of a capsaicin analogue supplement on 10-km time trial performance and physiological responses in amateur athletes. Methods: Twenty-one participants (age = 29.3 ± 5.5 years), completed two randomized, double-blind trials: capsaicin analogue condition [Capsiate (CAP) = 24 mg] or a placebo condition. The participants consumed two doses of 12 mg of capsaicin or placebo capsule 45 minutes before and immediately at the start of each trial. The time required to complete 10-km, lactate concentration, maximum heart rate (HRpeak), and rating of perceived exertion (RPE) were recorded. Results: 10-km time-trial performance (CAP = 45.07 ± 6.41 min vs. placebo = 45.13 ± 6.73, P = 0.828) was not statistically significant different between conditions. No statistically significant differences between conditions were detected for lactate concentration (P = 0.507), HRpeak (P = 0.897) and RPE (P = 0.517). Conclusion: Two doses of 12 mg Capsaicin analogue supplementation did not improve performance and physiological responses in a 10-km running time-trial in amateur athletes.


Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 34
Author(s):  
Ana Elisa von Ah Morano ◽  
Camila S. Padilha ◽  
Vinicius Aparecido Matos Soares ◽  
Fabiana Andrade Machado ◽  
Peter Hofmann ◽  
...  

Background: To investigate the acute effects of a capsaicin analogue supplement on 10 km time-trial performance and physiological responses in amateur athletes. Methods: Twenty-one participants (age = 29.3 ± 5.5 years, weight 74.2 ± 11.3 kg, height 176.0 ± 0.0 cm, fat mass 12.7 ± 3.8%, V˙O2max 62.7 ± 8.4 mL·k−1·min−1), completed two randomized, double-blind trials: capsaicin analogue condition (Capsiate (CAP) = 24 mg) or a placebo (PLA) condition. The participants consumed two doses of 12 mg of CAP or PLA capsule 45 min before and immediately at the start of each trial. The time required to complete 10 km, lactate concentration, maximum heart rate (HRpeak), and rating of perceived exertion (RPE) were recorded. Results: The 10 km time-trial performance (CAP = 45.07 ± 6.41 min vs. PLA = 45.13 ± 6.73, p = 0.828) was not statistically significantly different between conditions. No statistically significant differences between conditions were detected for lactate concentration (p = 0.507), HRpeak (p = 0.897) and RPE (p = 0.517). Conclusion: Two doses of a 12 mg Capsaicin analogue supplement did not improve performance and physiological responses in a 10 km running time-trial in amateur athletes.


Author(s):  
Naomi M. Cermak ◽  
Martin J. Gibala ◽  
Luc J.C. van Loon

Six days of dietary nitrate supplementation in the form of beetroot juice (~0.5 L/d) has been reported to reduce pulmonary oxygen uptake (VO2) during submaximal exercise and increase tolerance of high-intensity work rates, suggesting that nitrate can be a potent ergogenic aid. Limited data are available regarding the effect of nitrate ingestion on athletic performance, and no study has investigated the potential ergogenic effects of a small-volume, concentrated dose of beetroot juice. The authors tested the hypothesis that 6 d of nitrate ingestion would improve time-trial performance in trained cyclists. Using a double-blind, repeated-measures crossover design, 12 male cyclists (31 ± 3 yr, VO2peak = 58 ± 2 ml · kg−1 · min−1, maximal power [Wmax] = 342 ± 10 W) ingested 140 ml/d of concentrated beetroot (~8 mmol/d nitrate) juice (BEET) or a placebo (nitrate-depleted beetroot juice; PLAC) for 6 d, separated by a 14-d washout. After supplementation on Day 6, subjects performed 60 min of submaximal cycling (2 × 30 min at 45% and 65% Wmax, respectively), followed by a 10-km time trial. Time-trial performance (953 ± 18 vs. 965 ± 18 s, p < .005) and power output (294 ± 12 vs. 288 ± 12 W, p < .05) improved after BEET compared with PLAC supplementation. Submaximal VO2 was lower after BEET (45% Wmax = 1.92 ± 0.06 vs. 2.02 ± 0.09 L/min, 65% Wmax 2.94 ± 0.12 vs. 3.11 ± 0.12 L/min) than with PLAC (main effect, p < .05). Wholebody fuel selection and plasma lactate, glucose, and insulin concentrations did not differ between treatments. Six days of nitrate supplementation reduced VO2 during submaximal exercise and improved time-trial performance in trained cyclists.


Nutrients ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 657 ◽  
Author(s):  
Alexandre Marques ◽  
Alison Jesus ◽  
Bruna Giglio ◽  
Ana Marini ◽  
Patrícia Lobo ◽  
...  

Author(s):  
John L. Ivy ◽  
Lynne Kammer ◽  
Zhenping Ding ◽  
Bei Wang ◽  
Jeffrey R. Bernard ◽  
...  

Context:Not all athletic competitions lend themselves to supplementation during the actual event, underscoring the importance of preexercise supplementation to extend endurance and improve exercise performance. Energy drinks are composed of ingredients that have been found to increase endurance and improve physical performance.Purpose:The purpose of the study was to investigate the effects of a commercially available energy drink, ingested before exercise, on endurance performance.Methods:The study was a double-blind, randomized, crossover design. After a 12-hr fast, 6 male and 6 female trained cyclists (mean age 27.3 ± 1.7 yr, mass 68.9 ± 3.2 kg, and VO2 54.9 ± 2.3 ml · kg–1 · min–1) consumed 500 ml of either flavored placebo or Red Bull Energy Drink (ED; 2.0 g taurine, 1.2 g glucuronolactone, 160 mg caffeine, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 μg vitamin B12) 40 min before a simulated cycling time trial. Performance was measured as time to complete a standardized amount of work equal to 1 hr of cycling at 70% Wmax.Results:Performance improved with ED compared with placebo (3,690 ± 64 s vs. 3,874 ± 93 s, p < .01), but there was no difference in rating of perceived exertion between treatments. β-Endorphin levels increased during exercise, with the increase for ED approaching significance over placebo (p = .10). Substrate utilization, as measured by open-circuit spirometry, did not differ between treatments.Conclusion:These results demonstrate that consuming a commercially available ED before exercise can improve endurance performance and that this improvement might be in part the result of increased effort without a concomitant increase in perceived exertion.


2014 ◽  
Vol 117 (10) ◽  
pp. 1180-1187 ◽  
Author(s):  
Anders Kalsen ◽  
Morten Hostrup ◽  
Sebastian Karlsson ◽  
Peter Hemmersbach ◽  
Jens Bangsbo ◽  
...  

In a randomized, double-blind crossover design, we investigated the effect of the beta2-agonist terbutaline (TER) on endurance performance and substrate utilization in nine moderately trained men [maximum oxygen uptake (V̇o2 max) 58.9 ± 3.1 ml·min−1·kg−1]. Subjects performed 60 min of submaximal exercise (65–70% of V̇o2 max) immediately followed by a 300-kcal time trial with inhalation of either 15 mg of TER or placebo (PLA). Pulmonary gas exchange was measured during the submaximal exercise, and muscle biopsies were collected before and after the exercise bouts. Time trial performance was not different between TER and PLA (1,072 ± 145 vs. 1,054 ± 125 s). During the submaximal exercise, respiratory exchange ratio, glycogen breakdown (TER 266 ± 32, PLA 195 ± 28 mmol/kg dw), and muscle lactate accumulation (TER 20.3 ± 1.6, PLA 13.2 ± 1.2 mmol/kg dw) were higher ( P < 0.05) with TER than PLA. There was no difference between TER and PLA in net muscle glycogen utilization or lactate accumulation during the time trial. Intramyocellular triacylglycerol content did not change with treatment or exercise. Pyruvate dehydrogenase-E1α phosphorylation at Ser293 and Ser300 was lower ( P < 0.05) before submaximal exercise with TER than PLA, with no difference after the submaximal exercise and the time trial. Before submaximal exercise, acetyl-CoA carboxylase 2 (ACC2) phosphorylation at Ser221 was higher ( P < 0.05) with TER than PLA. There was no difference in phosphorylation of alpha 5′-AMP-activated protein kinase (αAMPK) at Thr172 between treatments. The present study suggests that beta2-agonists do not enhance 300-kcal time trial performance, but they increase carbohydrate metabolism in skeletal muscles during submaximal exercise independent of AMPK and ACC phosphorylation, and that this effect diminishes as drug exposure time, exercise duration, and intensity are increased.


Author(s):  
Rebecca J. Toone ◽  
James A. Betts

This study was designed to compare the effects of energy-matched carbohydrate (CHO) and carbohydrate-protein (CHO-PRO) supplements on cycling time-trial performance. Twelve competitive male cyclists and triathletes each completed 2 trials in a randomized and counterbalanced order that were separated by 5–10 d and applied in a double-blind manner. Participants performed a 45-min variable-intensity exercise protocol on a cycle ergometer while ingesting either a 9% CHO solution or a mixture of 6.8% CHO plus 2.2% protein in volumes providing 22 kJ/kg body mass. Participants were then asked to cycle 6 km in the shortest time possible. Blood glucose and lactate concentrations were measured every 15 min during exercise, along with measures of substrate oxidation via indirect calorimetry, heart rate, and ratings of perceived exertion. Mean time to complete the 6-km time trial was 433 ± 21 s in CHO trials and 438 ± 22 s in CHO-PRO trials, which represents a 0.94% (CI: 0.01, 1.86) decrement in performance with the inclusion of protein (p = .048). However, no other variable measured in this study was significantly different between trials. Reducing the quantity of CHO included in a supplement and replacing it with protein may not represent an effective nutritional strategy when the supplement is ingested during exercise. This may reflect the central ergogenic influence of exogenous CHO during such activity.


2010 ◽  
Vol 5 (2) ◽  
pp. 140-151 ◽  
Author(s):  
Mohammed Ihsan ◽  
Grant Landers ◽  
Matthew Brearley ◽  
Peter Peeling

Purpose:The effect of crushed ice ingestion as a precooling method on 40-km cycling time trial (CTT) performance was investigated.Methods:Seven trained male subjects underwent a familiarization trial and two experimental CTT which were preceded by 30 min of either crushed ice ingestion (ICE) or tap water (CON) consumption amounting to 6.8 g⋅kg-1 body mass. The CTT required athletes to complete 1200 kJ of work on a wind-braked cycle ergometer. During the CTT, gastrointestinal (Tgi) and skin (Tsk) temperatures, cycling time, power output, heart rate (HR), blood lactate (BLa), ratings of perceived exertion (RPE) and thermal sensation (RPTS) were measured at set intervals of work.Results:Precooling lowered the Tgi after ICE significantly more than CON (36.74 ± 0.67°C vs 37.27 ± 0.24°C, P < .05). This difference remained evident until 200 kJ of work was completed on the bike (37.43 ± 0.42°C vs 37.64 ± 0.21°C). No significant differences existed between conditions at any time point for Tsk, RPE or HR (P > .05). The CTT completion time was 6.5% faster in ICE when compared with CON (ICE: 5011 ± 810 s, CON: 5359 ± 820 s, P < .05).Conclusions:Crushed ice ingestion was effective in lowering Tgi and improving subsequent 40-km cycling time trial performance. The mechanisms for this enhanced exercise performance remain to be clarified.


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