scholarly journals The influence of acetaminophen on sprint interval treadmill running

Kinesiology ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Laura L. Park ◽  
Catherine E. Baker ◽  
Alvin Sum ◽  
Lawrence D. Hayes
Keyword(s):  
Power Output ◽  
Repeated Measures ◽  
Reaction Force ◽  
Body Height ◽  
Peak Oxygen Uptake ◽  
Treadmill Running ◽  
Peak Power Output ◽  
Vertical Ground Reaction Force ◽  
Mean Power ◽  
Exercise Induced

Although considerable research concerning the efficacy of analgesics in sport exists, there is a paucity of data concerning effects of acute acetaminophen (ACT) ingestion on sprint interval running exercise. This investigation concerned the effect of acute ACT ingestion on eight 30 s maximal treadmill sprints on a non-motorized treadmill, interspersed with two-minute rests in males (N=8, age 26±3 years, body height 174±7 cm, body mass 71±8 kg) in a placebo-controlled, randomized crossover design. A time x condition repeated measures analysis of variance (ANOVA) determined ACT ingestion did not influence mean power output, peak power output, peak vertical ground reaction force, peak oxygen uptake, or total distance completed (p>.05). Perceived pain was reduced by 8-15% during the final three sprints following ACT ingestion (p<.05). Data presented here suggest ACT may reduce exercise-induced pain during the latter stages of sprint interval treadmill running, without influencing performance.

N-acetylcysteine alters substrate metabolism during high-intensity cycle exercise in well-trained humans

2013 ◽  
Vol 38 (12) ◽  
pp. 1217-1227 ◽  
Author(s):  
Adam J. Trewin ◽  
Aaron C. Petersen ◽  
Francois Billaut ◽  
Leon R. McQuade ◽  
Bernie V. McInerney ◽  
...  
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Repeated Measures ◽  
Vastus Lateralis ◽  
Venous Blood ◽  
Time Trial ◽  
Peak Power Output ◽  
Mean Power ◽  
Double Blind ◽  
Substrate Metabolism

We investigated the effects of N-acetylcysteine (NAC) on metabolism during fixed work rate high-intensity interval exercise (HIIE) and self-paced 10-min time-trial (TT10) performance. Nine well-trained male cyclists (V̇O2peak, 69.4 ± 5.8 mL·kg−1·min−1; peak power output (PPO), 385 ± 43 W; mean ± SD) participated in a double-blind, repeated-measures, randomised crossover trial. Two trials (NAC supplementation and placebo) were performed 7 days apart consisting of 6 × 5 min HIIE bouts at 82% PPO (316 ± 40 W) separated by 1 min at 100 W, and then after 2 min of recovery at 100 W, TT10 was performed. Expired gases, venous blood, and electromyographic (EMG) data were collected. NAC did not influence blood glutathione but decreased lipid peroxidation compared with the placebo (P < 0.05). Fat oxidation was elevated with NAC compared with the placebo during HIIE bouts 5 and 6 (9.9 ± 8.9 vs. 3.9 ± 4.8 μmol·kg−1·min−1; P < 0.05), as was blood glucose throughout HIIE (4.3 ± 0.6 vs. 3.8 ± 0.6 mmol·L−1; P < 0.05). Blood lactate was lower with NAC after TT10 (3.3 ± 1.3 vs. 4.2 ± 1.3 mmol·L−1; P < 0.05). Median EMG frequency of the vastus lateralis was lower with NAC during HIIE (79 ± 10 vs. 85 ± 10 Hz; P < 0.05), but not TT10 (82 ± 11 Hz). Finally, NAC decreased mean power output 4.9% ± 6.6% (effect size = –0.3 ± 0.4, mean ± 90% CI) during TT10 (305 ± 57 W vs. 319 ± 45 W). These data suggest that NAC alters substrate metabolism and muscle fibre type recruitment during HIIE, which is detrimental to time-trial performance.

scholarly journals Comparison of the talk test and percent heart rate reserve for exercise prescription

Kinesiology ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 3-10 ◽  
Author(s):  
John P. Porcari ◽  
Katelyn Falck-Wiese
Keyword(s):  
Exercise Intensity ◽  
Power Output ◽  
Repeated Measures ◽  
Exercise Prescription ◽  
Ventilatory Threshold ◽  
Body Height ◽  
Cycle Ergometer ◽  
Peak Power Output ◽  
Group Exercise ◽  
Cycle Ergometer Test

Exercise intensity is traditionally prescribed using %HRmax, %HRR, %VO2max, or %VO2R. Recently, the Talk Test (TT) has been proposed as an alternative method to guide exercise intensity. However, it is unknown if prescribing exercise intensity solely using the TT can provoke training responses that are comparable to traditional guidelines. This study compared the responses to training using either the TT or %HRR. Forty-four subjects (17 males and 27 females: age=20.4±3.02 years; body height=170.5±9.79 cm; body weight=71.9±13.63 kg) completed an incremental maximal cycle ergometer test, were stratified by VO2max and gender, and randomly assigned to training groups guided by either %HRR (n=20) or the TT (n=24). Both groups completed 40-minute training sessions three days per week for 10 weeks. In the HRR group, exercise intensity was targeted (per ACSM guidelines) at 40-59% HRR for weeks 1-4, 50-59% HRR for weeks 5-8, and 60-79% HRR for weeks 9-10. In the TT group, exercise intensity was targeted at the highest power output (PO) that still allowed for comfortable speech. Changes in VO2max, peak power output (PPO), VO2 at ventilatory threshold (VT), and PO at VT were compared between the groups using two-way ANOVA with repeated measures. There were significant (p&lt;.05) pre vs. post increases in VO2max (TT=10.6%; HRR=11.5%), PPO (TT=19%; HR=14%), VO2 at VT (T=32.7%; HRR=56.9%), and PO at VT (TT=43.1%; HRR=38.6%) in both groups, with no significant (p&gt;0.05) interaction effect. Guiding exercise prescription using the TT is a simple and effective method for prescribing exercise intensity and elicits improvements in exercise performance that are comparable to the traditional %HRR guidelines.

scholarly journals Racing an Opponent: Alteration of Pacing, Performance, and Muscle-Force Decline but Not Rating of Perceived Exertion

2018 ◽  
Vol 13 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Marco J. Konings ◽  
Jordan Parkinson ◽  
Inge Zijdewind ◽  
Florentina J. Hettinga
Keyword(s):  
Power Output ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Muscle Force ◽  
Internal State ◽  
Rating Of Perceived Exertion ◽  
Voluntary Activation ◽  
Peak Power Output ◽  
Mean Power ◽  
Experimental Conditions

Purpose: Performing against a virtual opponent has been shown to invite a change in pacing and improve time-trial (TT) performance. This study explored how this performance improvement is established by assessing changes in pacing, neuromuscular function, and perceived exertion. Methods: After a peak-power-output test and a familiarization TT, 12 trained cyclists completed two 4-km TTs in randomized order on a Velotron cycle ergometer. TT conditions were riding alone (NO) and riding against a virtual opponent (OP). Knee-extensor performance was quantified before and directly after the TT using maximal voluntary contraction force (MVC), voluntary activation (VA), and potentiated doublet-twitch force (PT). Differences between the experimental conditions were examined using repeated-measures ANOVAs. Linear-regression analyses were conducted to associate changes in pacing to changes in MVC, VA, and PT. Results: OP was completed faster than NO (mean power output OP 289.6 ± 56.1 vs NO 272.2 ± 61.6 W; P = .020), mainly due to a faster initial pace. This was accompanied by a greater decline in MVC (MVC pre vs post −17.5% ± 12.4% vs −11.4% ± 10.9%, P = .032) and PT (PT pre vs post −23.1% ± 14.0% vs −16.2% ±11.4%, P = .041) after OP than after NO. No difference between conditions was found for VA (VA pre vs post −4.9% ± 6.7% vs −3.4% ± 5.0%, P = .274). Rating of perceived exertion did not differ between OP and NO. Conclusion: The improved performance when racing against a virtual opponent was associated with a greater decline in voluntary and evoked muscle force than riding alone, without a change in perceived exertion, highlighting the importance of human–environment interactions in addition to one’s internal state for pacing regulation and performance.

scholarly journals The Acute Impact of External Compression on Back Squat Performance in Competitive Athletes

2020 ◽  
Vol 17 (13) ◽  
pp. 4674
Author(s):  
Mariola Gepfert ◽  
Michal Krzysztofik ◽  
Maciej Kostrzewa ◽  
Jakub Jarosz ◽  
Robert Trybulski ◽  
...  
Keyword(s):  
Power Output ◽  
Repeated Measures ◽  
Arterial Occlusion ◽  
Peak Power Output ◽  
Training Experience ◽  
Mean Power ◽  
External Compression ◽  
Back Squat ◽  
Velocity Changes ◽  
Bar Velocity

The aim of the present study was to evaluate the effects of external compression with blood flow restriction on power output and bar velocity changes during the back-squat exercise (SQ). The study included 10 judo athletes (age = 28.4 ± 5.8 years; body mass = 81.3 ± 13.1 kg; SQ one-repetition maximum (1-RM) 152 ± 34 kg; training experience 10.7 ± 2.3 years). Methods: The experiment was performed following a randomized crossover design, where each participant performed three different exercise protocols: (1) control, without external compression (CONT); (2) intermittent external compression with pressure of 100% arterial occlusion pressure (AOP) (EC-100); and (3) intermittent external compression with pressure of 150% AOP (EC-150). To assess the differences between conditions, the participants performed 3 sets of 3 repetitions of the SQ at 70% 1-RM. The differences in peak power output (PP), mean power output (MP), peak bar velocity (PV), and mean bar velocity (MV) between the three conditions were examined using repeated measures two-way ANOVA. Results: The post hoc analysis for the main effect of conditions showed a significant increase in PP (p = 0.03), PV (p = 0.02), MP (p = 0.04), and MV (p = 0.03), for the EC-150, compared to the CONT. Furthermore, a statistically significant increase in PP (p = 0.04), PV (p = 0.03), MP (p = 0.02), and MV (p = 0.01) were observed for the EC-150 compared to EC-100. There were no significant changes in PP, PV, MP, and MV, between EC-100 and CONT conditions. Conclusion: The results indicate that the use of extremely high-pressure external compression (150% AOP) during high-loaded (70% 1-RM) lower limb resistance exercise elicits an acute increase in power output and bar velocity.

Oxygen uptake during upper body and lower body Wingate anaerobic tests

2014 ◽  
Vol 39 (12) ◽  
pp. 1345-1351 ◽  
Author(s):  
Michael Price ◽  
Christopher Beckford ◽  
Adam Dorricott ◽  
Cameron Hill ◽  
Megan Kershaw ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Anaerobic Power ◽  
Peak Oxygen Uptake ◽  
Gas Analysis ◽  
Upper Body ◽  
Peak Power Output ◽  
Lower Body ◽  
Mean Power ◽  
Exercise Tests

The aim of this study was to determine the aerobic contribution to upper body and lower body Wingate Anaerobic tests (WAnT). Eight nonspecifically trained males volunteered to take part in this study. Participants undertook incremental exercise tests for peak oxygen uptake and two 30-s WAnT (habituation and experimental) for both the upper and lower body. The resistive loadings used were 0.040 and 0.075 kg·kg body mass−1, respectively. Peak power output (PPO) and mean power output (MPO) were calculated for each WAnT. The aerobic contribution of each WAnT was assessed using breath by breath expired gas analysis. Peak oxygen uptake was lower for the upper body when compared with the lower body (P = 0.001). Similarly, PPO and MPO were greater for the lower body (both P < 0.001). Absolute oxygen uptake during the upper body WAnT was lower than for the lower body (P = 0.013), whereas relative oxygen uptake (% peak oxygen uptake) was similar (P = 0.997). The mean aerobic contribution for the upper body WAnT (43.5% ± 29.3%) was greater than for the lower body (29.4% ± 15.8%; P < 0.001). The greater aerobic contribution to the WAnT observed for the upper body in comparison with the lower body is likely due to methodological differences in upper and lower body WAnT protocols and potentially differences in anaerobic power production and exercise efficiency. The results of this study suggest that differences may exist for the aerobic contribution of upper and lower body Wingate anaerobic tests.

Exercise slightly above the maximal lactate steady state reduces self-efficacy and increases negative affect

2019 ◽  
Author(s):  
James Graeme Wrightson ◽  
Louis Passfield
Keyword(s):  
Steady State ◽  
Negative Affect ◽  
Power Output ◽  
Self Efficacy ◽  
Repeated Measures ◽  
Physiological State ◽  
Constant Load ◽  
Peak Power Output ◽  
Time To Exhaustion ◽  
Maximal Lactate Steady State

Objectives: To examine the effect of exercise at and slightly above the maximal lactate steady state (MLSS) on self-efficacy, affect and effort, and their associations with exercise tolerance.Design: Counterbalanced, repeated measures designMethod: Participants performed two 30‐minute constant‐load cycling exercise at a power output equal to that at MLSS and 10 W above MLSS, immediately followed by a time‐to‐exhaustion test at 80% of their peak power output. Self-efficacy, affect and effort were measured before and after 30 minutes of cycling at and above MLSS.Results: Negative affect and effort higher, and self-efficacy and time to exhaustion were reduced, following cycling at MLSS + 10 W compared to cycling at the MLSS. Following exercise at the MLSS self-efficacy, affect and effort were all associated with subsequent time-to exhaustion. However, following exercise at MLSS + 10 W, only affect was associated with time-to exhaustion. Conclusions: Self efficacy, affect and effort are profoundly affected by physiological state, highlighting the influence of somatic states on perceptions and emotions during exercise. The affective response to exercise appears to be associated with exercise tolerance, indicating that the emotional, as well as physiological, responses should be considered when prescribing exercise training.

Abstract P134: Preliminary Data: Dietary Nitrate Supplementation Does Not Extend Dry Static Apnea Or Wingate Performance

Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Colin Carriker ◽  
Phillip Armentrout ◽  
Sarah Levine ◽  
James Smoliga
Keyword(s):  
Power Output ◽  
Preliminary Data ◽  
Repeated Measures ◽  
Peak Power ◽  
Hold Time ◽  
Wingate Test ◽  
Peak Power Output ◽  
Breath Hold ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

Introduction: Previous studies have examined dietary nitrate supplementation and its effects on dry static apnea, and peak power. Dietary nitrate supplementation has been found to increase maximal apnea and peak power output. The purpose of this study was to determine the effects of beetroot juice on dry static apnea and Wingate performance. Hypothesis: Dietary nitrate will improve maximal breath hold time and peak power output. Dietary nitrate will improve tolerance to CO2, thereby improving maximal breath hold time and anaerobic capacity. Methods: In a randomized, double-blind, counterbalanced study, five healthy males (20.4±0.89 years) visited the lab on 3 separate occasions each separated by one week. Visit 1 served as a Wingate and breath hold familiarization visit. Prior to visits 2 and 3 participants were instructed to drink a beverage either a placebo (negligible nitrate content, PL) or dietary nitrate rich beverage (12.4 mmol nitrate, NIT) during the 4 days leading up to their next visit. Visits 2 and 3 consisted of two submaximal breath holds (80% of maximal determined during visit 1), with 2 minutes of rest between and three minutes of rest preceding the final breath hold for maximal duration. Finally, participants completed a standardized 10-minute warmup on the cycle ergometer before completing a 30-second maximal effort Wingate test. Results: A linear mixed effects model was used to determine whether treatment (NIT vs. PL) was associated with differences in VCO2 or PetCO2. Time (0, 10, 20, 30 min post-breath hold) and Treatment both served as repeated measures. Models were developed using multiple repeated measures covariance matrix structures, and the model with the lowest AIC was chosen as the final model. The interaction between time and treatment was included in the original models, and was removed if it was not statistically significant. Time was a statistically significant factor for VCO2 and PetCO2 (p < 0.001). Treatment, and the Time x Treatment interaction was not significant for either variable. No differences between NIT and PL were observed during the Wingate test for either time to peak power (5.02±2.45 and 6.2±2.43 sec, respectively) or maximal power (9.73±1.01 and 9.72±1.03 watts/kg, respectively) and fatigue index (49.42±14.98 and 47.30±6.99 watts/sec, respectively). Conclusion: Preliminary data indicates that in a general population four days of dietary nitrate supplementation may not improve breath hold time, tolerance to carbon dioxide in the lungs, or Wingate performance.

Variability of vertical ground reaction forces collected with one and two force plates in healthy dogs

2015 ◽  
Vol 28 (05) ◽  
pp. 318-322 ◽  
Author(s):  
M. Stejskal ◽  
B. T. Torres ◽  
G. S. Sandberg ◽  
J. A. Sapora ◽  
R. K. Dover ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Reaction Force ◽  
Force Plate ◽  
Plate Versus ◽  
Vertical Force ◽  
Vertical Ground Reaction Force ◽  
Coefficients Of Variation ◽  
Vertical Ground ◽  
Healthy Dogs ◽  
Collection Time

SummaryObjective: To compare peak vertical force (PVF) and vertical impulse (VI) data collected with one and two force plates during the same collection time period in healthy dogs at a trot.Animals: Seventeen healthy client-owned adult dogs.Methods: Vertical ground reaction force (GRF) data were collected in a crossover study design, with four sessions on two consecutive days, and then two weeks apart (days 1, 2, 15, and 16) using both one and two force plates collection methods. A repeated measures model analysis of variance (ANOVA) was used to test for differences in force plate PVF, VI, and average time per trial (ATT) between days, weeks, and systems (1 plate versus 2 plates). Coefficients of variation for PVF and VI were also calculated separately by forelimbs and hindlimbs, plates, day, and week.Results: The time required to obtain a valid trial was significantly longer using a single force plate when compared with two force plates. Comparing GRF data for all dogs, significant differences in PVF data were found between one and two force plates, however, these differences were diminutive in absolute magnitude, and of unknown clinical importance. Examination of the coefficients of variation for PVF and VI during the different collection periods yielded similar results.Conclusions: Use of two force plates decreased trial repetition and collection time. Vertical GRF data had a similar coefficient of variation with either one or two force plates collection techniques in healthy dogs.

scholarly journals The Ingestion of 39 or 64 g·hr−1 of Carbohydrate is Equally Effective at Improving Endurance Exercise Performance in Cyclists

2015 ◽  
Vol 25 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Michael L. Newell ◽  
Angus M. Hunter ◽  
Claire Lawrence ◽  
Kevin D. Tipton ◽  
Stuart D. R. Galloway
Keyword(s):  
Power Output ◽  
Statistical Significance ◽  
Time Trial ◽  
Cycling Performance ◽  
Constant Load ◽  
Peak Power Output ◽  
Task Completion ◽  
Intake Rate ◽  
Mean Power ◽  
Pacing Strategy

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.

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