No additive effect of acetaminophen when co-ingested with caffeine on cycling performance in well-trained young men

Author(s):  
Søren Jessen ◽  
Kasper Eibye ◽  
Peter Møller Christensen ◽  
Morten Hostrup ◽  
Jens Bangsbo

We investigated the effect of caffeine and acetaminophen on power output during a 6-min performance-test, peripheral fatigue, and muscle protein kinase A (PKA) substrate-phosphorylation. Fourteen men (age(mean±SD): 26±6 years; V̇O2max: 63.9±5.0 mL∙min-1∙kg-1) completed four randomized trials with acetaminophen (1500 mg), caffeine (5 mg∙kgbw-1), combined caffeine and acetaminophen (caffeine+acetaminophen) or placebo. Mean power output during the 6-min performance-test (placebo mean:312±41 W) was higher with caffeine (+5 W;95%CI: 1 to 9;P=0.017) and caffeine+acetaminophen (+6 W;95%CI: 0 to 12;P=0.049) than placebo, but not with acetaminophen (+1 W;95%CI: -4 to 7;P=0.529). Decline in quadriceps maximal isometric voluntary torque immediately after the performance-test was lower (treatment×time; P=0.035) with acetaminophen (-40 Nm;95%CI:-53 to -30;P<0.001) and caffeine+acetaminophen (-44 Nm;95%CI: -58 to -30;P<0.001) than placebo (-53 Nm;95%CI: -71 to -39;P<0.001) but was similar with caffeine (-54 Nm;95%CI: -69 to -38;P<0.001). Muscle phosphocreatine content decreased more during the performance-test (treatment×time;P=0.036) with caffeine+acetaminophen (-55 mmol∙kgdw-1;95%CI: -65 to -46;P<0.001) than placebo (-40 mmol∙kgdw-1;95%CI: -52 to -24;P<0.001). Muscle net lactate accumulation was not different from placebo (+85 mmol∙kgdw-1;95%CI: 60 to 110;P<0.001) for any treatment (treatment×time;P=0.066), being +75 mmol∙kgdw-1 (95%CI: 51 to 99;P<0.001) with caffeine, +76 mmol∙kgdw-1 (95%CI: 58 to 96;P<0.001) with acetaminophen, and +103 mmol∙kgdw-1 (95%CI: 89 to 115;P<0.001) with caffeine+acetaminophen. Decline in muscle ATP and glycogen content and increase in PKA substrate-phosphorylation was not different between treatments (treatment×time;P>0.1). Thus, acetaminophen provides no additive performance enhancing effect to caffeine during 6-min maximal cycling. In addition, change in PKA activity is likely not a major mechanism of performance improvement with caffeine.

2015 ◽  
Vol 25 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Michael L. Newell ◽  
Angus M. Hunter ◽  
Claire Lawrence ◽  
Kevin D. Tipton ◽  
Stuart D. R. Galloway

In an investigator-blind, randomized cross-over design, male cyclists (mean± SD) age 34.0 (± 10.2) years, body mass 74.6 (±7.9) kg, stature 178.3 (±8.0) cm, peak power output (PPO) 393 (±36) W, and VO2max 62 (±9) ml·kg−1min−1 training for more than 6 hr/wk for more than 3y (n = 20) completed four experimental trials. Each trial consisted of a 2-hr constant load ride at 95% of lactate threshold (185 ± 25W) then a work-matched time trial task (~30min at 70% of PPO). Three commercially available carbohydrate (CHO) beverages, plus a control (water), were administered during the 2-hr ride providing 0, 20, 39, or 64g·hr−1 of CHO at a fluid intake rate of 1L·hr−1. Performance was assessed by time to complete the time trial task, mean power output sustained, and pacing strategy used. Mean task completion time (min:sec ± SD) for 39g·hr−1 (34:19.5 ± 03:07.1, p = .006) and 64g·hr−1 (34:11.3 ± 03:08.5 p = .004) of CHO were significantly faster than control (37:01.9 ± 05:35.0). The mean percentage improvement from control was −6.1% (95% CI: −11.3 to −1.0) and −6.5% (95% CI: −11.7 to −1.4) in the 39 and 64g·hr−1 trials respectively. The 20g·hr−1 (35:17.6 ± 04:16.3) treatment did not reach statistical significance compared with control (p = .126) despite a mean improvement of −3.7% (95% CI −8.8−1.5%). No further differences between CHO trials were reported. No interaction between CHO dose and pacing strategy occurred. 39 and 64g·hr−1 of CHO were similarly effective at improving endurance cycling performance compared with a 0g·hr−1 control in our trained cyclists.


2019 ◽  
Vol 44 (2) ◽  
pp. 208-215 ◽  
Author(s):  
Paul T. Morgan ◽  
Anni Vanhatalo ◽  
Joanna L. Bowtell ◽  
Andrew M. Jones ◽  
Stephen J. Bailey

Recent research suggests that acute consumption of pharmacological analgesics can improve exercise performance, but the ergogenic potential of ibuprofen (IBP) administration is poorly understood. This study tested the hypothesis that IBP administration would enhance maximal exercise performance. In one study, 13 physically active males completed 60 × 3-s maximal voluntary contractions (MVCs) of the knee extensors interspersed with 2-s passive recovery periods, on 2 occasions, with the critical torque (CT) estimated as the mean torque over the last 12 contractions (part A). In another study, 16 active males completed two 3-min all-out tests against a fixed resistance on an electronically braked cycle ergometer, with the critical power estimated from the mean power output over the final 30 s of the test (part B). All tests were completed 60 min after ingestion of maltodextrin (placebo, PL) or 400 mg of IBP. Peripheral nerve stimulation was administered at regular intervals and electromyography was measured throughout. For part A, mean torque (IBP: 60% ± 13% of pre-exercise MVC; PL: 58% ± 14% of pre-exercise MVC) and CT (IBP: 41% ± 16% of pre-exercise MVC; PL: 40% ± 15% of pre-exercise MVC) were not different between conditions (P > 0.05). For part B, end-test power output (IBP: 292 ± 28 W; PL: 288 ± 31 W) and work done (IBP: 65.9 ± 5.9 kJ; PL: 65.4 ± 6.4 kJ) during the 3-min all-out cycling tests were not different between conditions (all P > 0.05). For both studies, neuromuscular fatigue declined at a similar rate in both conditions (P > 0.05). In conclusion, acute ingestion of 400 mg of IBP does not improve single-leg or maximal cycling performance in healthy humans.


2016 ◽  
Vol 41 (8) ◽  
pp. 825-831 ◽  
Author(s):  
Rogério Santos de Oliveira Cruz ◽  
Rafael Alves de Aguiar ◽  
Tiago Turnes ◽  
Amadeo Félix Salvador ◽  
Fabrizio Caputo

It has been demonstrated that ischemic preconditioning (IPC) improves endurance performance. However, the potential benefits during anaerobic events and the mechanism(s) underlying these benefits remain unclear. Fifteen recreational cyclists were assessed to evaluate the effects of IPC of the upper thighs on anaerobic performance, skeletal muscle activation, and metabolic responses during a 60-s sprint performance. After an incremental test and a familiarization visit, subjects were randomly submitted in visits 3 and 4 to a performance protocol preceded by intermittent bilateral cuff inflation (4 × (5 min of blood flow restriction + 5 min reperfusion)) at either 220 mm Hg (IPC) or 20 mm Hg (control). To increase data reliability, each intervention was replicated, which was also in a random manner. In addition to the mean power output, the pulmonary oxygen uptake, blood lactate kinetics, and quadriceps electromyograms (EMGs) were analyzed during performance and throughout 45 min of passive recovery. After IPC, performance was improved by 2.1% compared with control (95% confidence intervals of 0.8% to 3.3%, P = 0.001), followed by increases in (i) the accumulated oxygen deficit, (ii) the amplitude of blood lactate kinetics, (iii) the total amount of oxygen consumed during recovery, and (iv) the overall EMG amplitude (P < 0.05). In addition, the ratio between EMG and power output was higher during the final third of performance after IPC (P < 0.05). These results suggest an increased skeletal muscle activation and a higher anaerobic contribution as the ultimate responses of IPC on short-term exercise performance.


2014 ◽  
Vol 24 (6) ◽  
pp. 605-612 ◽  
Author(s):  
Edwin Chong ◽  
Kym J. Guelfi ◽  
Paul A. Fournier

This study investigated whether combined ingestion and mouth rinsing with a carbohydrate solution could improve maximal sprint cycling performance. Twelve competitive male cyclists ingested 100 ml of one of the following solutions 20 min before exercise in a randomized double-blinded counterbalanced order (a) 10% glucose solution, (b) 0.05% aspartame solution, (c) 9.0% maltodextrin solution, or (d) water as a control. Fifteen min after ingestion, repeated mouth rinsing was carried out with 11 × 15 ml bolus doses of the same solution at 30-s intervals. Each participant then performed a 45-s maximal sprint effort on a cycle ergometer. Peak power output was significantly higher in response to the glucose trial (1188 ± 166 W) compared with the water (1036 ± 177 W), aspartame (1088 ± 128 W) and maltodextrin (1024 ± 202W) trials by 14.7 ± 10.6, 9.2 ± 4.6 and 16.0 ± 6.0% respectively (p < .05). Mean power output during the sprint was significantly higher in the glucose trial compared with maltodextrin (p < .05) and also tended to be higher than the water trial (p = .075). Glucose and maltodextrin resulted in a similar increase in blood glucose, and the responses of blood lactate and pH to sprinting did not differ significantly between treatments (p > .05). These findings suggest that combining the ingestion of glucose with glucose mouth rinsing improves maximal sprint performance. This ergogenic effect is unlikely to be related to changes in blood glucose, sweetness, or energy sensing mechanisms in the gastrointestinal tract.


2018 ◽  
Vol 13 (3) ◽  
pp. 268-273 ◽  
Author(s):  
Ana B. Peinado ◽  
Nuria Romero-Parra ◽  
Miguel A. Rojo-Tirado ◽  
Rocío Cupeiro ◽  
Javier Butragueño ◽  
...  

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.


2015 ◽  
Vol 10 (3) ◽  
pp. 278-284 ◽  
Author(s):  
Avish P. Sharma ◽  
Adrian D. Elliott ◽  
David J. Bentley

Context:Road cycle racing is characterized by significant variability in exercise intensity. Existing protocols attempting to model this aspect display inadequate variation in power output. Furthermore, the reliability of protocols representative of road cycle racing is not well known. There are also minimal data regarding the physiological parameters that best predict performance during variable-power cycling.Purpose:To determine the reliability of mean power output during a new test of variable-power cycling and establish the relationship between physiological attributes typically measured during an incremental exercise test and performance during the variable-power cycling test (VCT).Methods:Fifteen trained male cyclists (mean ± SD age 33 ± 6.5 y, VO2max 57.9 ± 4.8 mL · kg−1 · min−1) performed an incremental exercise test to exhaustion for determination of physiological attributes, 2 VCTs (plus familiarization), and a 30-km time trial. The VCT was modeled on data from elite men’s road racing and included significant variation in power output.Results:Mean power output during the VCT showed good reliability (r = .92, CV% = 1.98). Relative power during the self-paced sections of the VCT was most correlated with maximal aerobic power (r = .79) and power at the second ventilatory threshold (r = .69). Blood lactate concentration showed poor reliability between trials (CV% = 13.93%).Conclusions:This study has demonstrated a new reliable protocol simulating the stochastic nature of road cycling races. Further research is needed to determine which factors predict performance during variable-power cycling and the validity of the test in monitoring longitudinal changes in cycling performance.


2018 ◽  
Vol 43 (9) ◽  
pp. 902-908 ◽  
Author(s):  
Kévin Rinaldi ◽  
Than Tran Trong ◽  
Florence Riera ◽  
Katharina Appel ◽  
Olivier Hue

Endurance exercise performance is impaired in a hot and humid environment. This study compared the effects of cold water immersion, with (CMWI) and without (CWI) menthol, on the recovery of cycling performance. Eight heat-acclimatized cyclists (age, 24.1 ± 4.4 years; mass, 65.3 ± 5.2 kg) performed 2 randomized sessions, each consisting of a 20-min cycling trial (T1) followed by 10 min of immersion during recovery and then a second 20-min cycling trial (T2). Mean power output and perceived exertion (RPE) were recorded for both trials. Rectal (Trec) and skin temperatures were measured before and immediately after T1, immersion, and T2. Perceived thermal sensation (TS) and comfort were measured immediately after T1 and T2. Power output was significantly improved in T2 compared with T1 in the CMWI condition (+15.6%). Performance did not change in the CWI condition. After immersion, Trec was lower in CWI (–1.17 °C) than in CMWI (–0.6 °C). TS decreased significantly after immersion in both conditions. This decline was significantly more pronounced in CMWI (5.9 ± 1 to 3.6 ± 0.5) than in CWI (5.6 ± 0.9 to 4.4 ± 1.2). In CMWI, RPE was significantly higher in T1 (6.57 ± 0.9) than in T2 (5.14 ± 1.25). However, there was no difference in TC. This study suggests that menthol immersion probably (i) improves the performance of a repeated 20-min cycling bout, (ii) decreases TS, and (iii) impairs thermoregulation processes.


Author(s):  
Rogério Santos de Oliveira Cruz ◽  
Rafael Alves de Aguiar ◽  
Tiago Turnes ◽  
Felipe Domingos Lisbôa ◽  
João Antônio Gesser Raimundo ◽  
...  

The aims of the present study were to assess the reliability of long sprint cycling performance in a group of recreationally trained cyclists and to provide thresholds for changes in performance for this particular group of subjects in repeated measures designs through a scale of magnitudes. Repeatability of mean power output during a 1-min cycling time trial was assessed in a group of 15 recreationally trained cyclists (26 ± 5, years, 176 ± 5 cm, 78 ± 8 kg). They were tested on separate days, approximately one week apart. The test and retest values for the whole group of cyclists were 7.0 ± 0.5 W/kg and 6.9 ± 0.6 W/kg (systematic change and 90% confidence limits of -1.0% ± 1.1%). Our results indicated good test-retest reproducibility (typical error of 1.8%, 90% confidence limits of 1.4% to 2.6%; intraclass correlation coefficient of 0.96, confidence limits of 0.91 to 0.99), but suggested a reduction of mean power for the “slower” subjects on retest (-2.0%, 90% confidence limits of ±1.8%). If not monitored, this systematic decrease could interfere in results of studies utilizing groups with similar performance levels, particularly investigating strategies to improve performance in sprint cycling exercises around 1 min. The thresholds for moderate, large, very large and extremely large effects for mean power output on long sprint cycling performance are about 0.4%, 1.3%, 2.3%, 3.6%, and 5.8%, respectively.


2013 ◽  
Vol 8 (3) ◽  
pp. 300-306 ◽  
Author(s):  
Matthew W. Driller ◽  
Shona L. Halson

Purpose:Compression garments have been commonly used in a medical setting as a method to promote blood flow. Increases in blood flow during exercise may aid in the delivery of oxygen to the exercising muscles and, subsequently, enhance performance. The aim of the current study was to investigate the effect of wearing lower body compression garments during a cycling test.Methods:Twelve highly trained cyclists (mean ± SD age 30 ± 6 y, mass 75.6 ± 5.8 kg, VO2peak 66.6 ± 3.4 mL · kg−1 · min−1) performed two 30-min cycling bouts on a cycle ergometer in a randomized, crossover design. During exercise, either full-length lower body compression garments (COMP) or above-knee cycling shorts (CON) were worn. Cycling bouts involved 15 min at a fixed workload (70% of VO2max power) followed by a 15-min time trial. Heart rate (HR) and blood lactate (BL) were measured during the fixed-intensity component of the cycling bout to determine the physiological effect of the garments. Calf girth (CG), thigh girth (TG) and perceived soreness (PS) were measured preexercise and postexercise.Results:COMP produced a trivial effect on mean power output (ES = .14) compared with CON (mean ± 95% CI 1.3 ±1.0). COMP was also associated with a lower HR during the fixed-workload section of the test (−2.6% ± 2.3%, ES = −.38). There were no differences between groups for BL, CG, TG, and PS.Conclusion:Wearing compression garments during cycling may result in trivial performance improvements of ~1% and may enhance oxygen delivery to the exercising muscles.


2019 ◽  
Vol 14 (6) ◽  
pp. 727-732
Author(s):  
Naroa Etxebarria ◽  
Megan L. Ross ◽  
Brad Clark ◽  
Louise M. Burke

Purpose: The authors investigated the potential benefit of ingesting 2 mM of quinine (bitter tastant) on a 3000-m cycling time-trial (TT) performance. Methods: Nine well-trained male cyclists (maximal aerobic power: 386 [38] W) performed a maximal incremental cycling ergometer test, three 3000-m familiarization TTs, and four 3000-m intervention TTs (∼4 min) on consecutive days. The 4 interventions were (1) 25 mL of placebo, (2) a 25-mL sweet solution, and (3) and (4) repeat 25 mL of 2-mM quinine solutions (Bitter1 and Bitter2), 30 s before each trial. Participants self-selected their gears and were only aware of distance covered. Results: Overall mean power output for the full 3000 m was similar for all 4 conditions: placebo, 348 (45) W; sweet, 355 (47) W; Bitter1, 354 (47) W; and Bitter2, 355 (48) W. However, quinine administration in Bitter1 and Bitter2 increased power output during the first kilometer by 15 ± 11 W and 21 ± 10 W (mean ± 90% confidence limits), respectively, over placebo, followed by a decay of 34 ± 32 W during Bitter1 and Bitter2 during the second kilometer. Bitter2 also induced a 11 ± 13-W increase during the first kilometer compared with the sweet condition. Conclusions: Ingesting 2 mM of quinine can improve cycling performance during the first one-third of a 3000-m TT and could be used for sporting events lasting ∼80 s to potentially improve overall performance.


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