scholarly journals Metabolic consequences of β-alanine supplementation during exhaustive supramaximal cycling and 4000-m time-trial performance

2016 ◽  
Vol 41 (8) ◽  
pp. 864-871 ◽  
Author(s):  
Phillip M. Bellinger ◽  
Clare L. Minahan
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Anaerobic Power ◽  
Anaerobic Capacity ◽  
Time Trial ◽  
Time To Exhaustion ◽  
Cycling Test ◽  
Cycling Time Trial ◽  
Aerobic And Anaerobic

The present study investigated the effects of β-alanine supplementation on the resultant blood acidosis, lactate accumulation, and energy provision during supramaximal-intensity cycling, as well as the aerobic and anaerobic contribution to power output during a 4000-m cycling time trial (TT). Seventeen trained cyclists (maximal oxygen uptake = 4.47 ± 0.55 L·min−1) were administered 6.4 g of β-alanine (n = 9) or placebo (n = 8) daily for 4 weeks. Participants performed a supramaximal cycling test to exhaustion (equivalent to 120% maximal oxygen uptake) before (PreExh) and after (PostExh) the 4-week supplementation period, as well as an additional postsupplementation supramaximal cycling test identical in duration and power output to PreExh (PostMatch). Anaerobic capacity was quantified and blood pH, lactate, and bicarbonate concentrations were measured pre-, immediately post-, and 5 min postexercise. Subjects also performed a 4000-m cycling TT before and after supplementation while the aerobic and anaerobic contributions to power output were quantified. β-Alanine supplementation increased time to exhaustion (+12.8 ± 8.2 s; P = 0.041) and anaerobic capacity (+1.1 ± 0.7 kJ; P = 0.048) in PostExh compared with PreExh. Performance time in the 4000-m TT was reduced following β-alanine supplementation (−6.3 ± 4.6 s; P = 0.034) and the mean anaerobic power output was likely to be greater (+6.2 ± 4.5 W; P = 0.035). β-Alanine supplementation increased time to exhaustion concomitant with an augmented anaerobic capacity during supramaximal intensity cycling, which was also mirrored by a meaningful increase in the anaerobic contribution to power output during a 4000-m cycling TT, resulting in an enhanced overall performance.

Is Acute Static Stretching Able to Reduce the Time to Exhaustion at Power Output Corresponding to Maximal Oxygen Uptake?

2010 ◽  
Vol 24 (6) ◽  
pp. 1650-1656 ◽  
Author(s):  
Felipe A Samogin Lopes ◽  
Elton M Menegon ◽  
Emerson Franchini ◽  
Valmor Tricoli ◽  
Rômulo C de M. Bertuzzi
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Time To Exhaustion ◽  
Static Stretching

Training Prescription Guided by Heart-Rate Variability in Cycling

2019 ◽  
Vol 14 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Alejandro Javaloyes ◽  
Jose Manuel Sarabia ◽  
Robert Patrick Lamberts ◽  
Manuel Moya-Ramon
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Peak Power ◽  
Performance Enhancement ◽  
Time Trial ◽  
Peak Power Output ◽  
Road Cycling

Purpose: Road cycling is a sport with extreme physiological demands. Therefore, there is a need to find new strategies to improve performance. Heart-rate variability (HRV) has been suggested as an effective alternative for prescribing training load against predefined training programs. The purpose of this study was to examine the effect of training prescription based on HRV in road cycling performance. Methods: Seventeen well-trained cyclists participated in this study. After an initial evaluation week, cyclists performed 4 baseline weeks of standardized training to establish their resting HRV. Then, cyclists were divided into 2 groups, an HRV-guided group and a traditional periodization group, and they carried out 8 training weeks. Cyclists performed 2 evaluation weeks, after and before a training week. During the evaluation weeks, cyclists performed a graded exercise test to assess maximal oxygen uptake, peak power output, and ventilatory thresholds with their corresponding power output (VT1, VT2, WVT1, and WVT2, respectively) and a 40-min simulated time trial. Results: The HRV-guided group improved peak power output (5.1% [4.5%]; P = .024), WVT2 (13.9% [8.8%]; P = .004), and 40-min all-out time trial (7.3% [4.5%]; P = .005). Maximal oxygen uptake and WVT1 remained similar. The traditional periodization group did not improve significantly after the training week. There were no differences between groups. However, magnitude-based inference analysis showed likely beneficial and possibly beneficial effects for the HRV-guided group instead of the traditional periodization group in 40-min all-out time trial and peak power output, respectively. Conclusion: Daily training prescription based on HRV could result in a better performance enhancement than a traditional periodization in well-trained cyclists.

Morning–evening differences in response to exhaustive severe-intensity exercise

2014 ◽  
Vol 39 (2) ◽  
pp. 248-254 ◽  
Author(s):  
David W. Hill
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Anaerobic Capacity ◽  
Oxygen Uptake Kinetics ◽  
Sport Performance ◽  
Time Of Day ◽  
Uptake Kinetics ◽  
Oxygen Deficit ◽  
Time To Exhaustion ◽  
Severe Intensity

The aim was to investigate the effect of time of day on 4 variables that are related to sport performance. Twenty healthy young men (mean ± SD: 22 ± 3 years, 1.78 ± 0.08 m, 72.0 ± 7.0 kg) performed exhaustive severe-intensity cycle ergometer tests at 278 ± 35 W (3.8 ± 0.4 W·kg–1) in the morning (between 0630 h and 0930 h) and in the evening (between 1700 h and 2000 h). Despite that gross efficiency was lower in the evening (estimated oxygen demand was 6% higher, P < 0.05), time to exhaustion was 20% greater (P < 0.01) in the evening (329 ± 35 s) than in the morning (275 ± 29 s). Performance in the evening was associated with a 4% higher (P < 0.01) maximal oxygen uptake (54 ± 7 mL·kg–1·min–1 vs. 52 ± 6 mL·kg–1·min–1, for the evening and the morning, respectively) and a 7% higher (P < 0.01) anaerobic capacity (as reflected by maximal accumulated oxygen deficit: 75 ± 9 mL·kg–1 vs. 70 ± 7 mL·kg–1, for the evening and the morning, respectively). In addition, oxygen uptake kinetics was faster in the evening, which resulted in slower utilization of the anaerobic reserves. It is concluded that modest morning–evening differences in maximal oxygen uptake, anaerobic capacity, and oxygen uptake kinetics conflate to produce a markedly longer performance in the evening than in the morning. Time of day must be considered for exercise testing and perhaps for exercise training.

Similar maximal oxygen uptake assessment from a step cycling incremental test and verification tests on the same or different day

2020 ◽  
Vol 45 (4) ◽  
pp. 357-361 ◽  
Author(s):  
Leonardo Trevisol Possamai ◽  
Fernando de Souza Campos ◽  
Paulo Cesar do Nascimento Salvador ◽  
Rafael Alves de Aguiar ◽  
Luiz Guilherme Antonacci Guglielmo ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Peak Power ◽  
Individual Variability ◽  
Peak Power Output ◽  
Time To Exhaustion ◽  
Incremental Test ◽  
Incremental Protocol

The present study aimed to compare maximal oxygen uptake of a step incremental test with time to exhaustion verification tests (TLIM) performed on the same or different day. Nineteen recreationally trained cyclists (age: 23 ± 2.7 years; maximal oxygen uptake: 48.0 ± 5.8 mL·kg−1·min−1) performed 3 maximal tests as follows: (i) same day: an incremental test with 3-min stages followed by a TLIM at 100% of peak power output of the incremental test (TLIM-SAME) interspaced by 15 min; and (ii) different day: a TLIM at 100% of peak power output of the incremental test (TLIM-DIFF). The maximal oxygen uptake was determined for the 3 tests. The maximal oxygen uptake was not different among the tests (incremental: 3.83 ± 0.41; TLIM-SAME: 3.72 ± 0.42; TLIM-DIFF: 3.75 ± 0.41 L·min−1; P = 0.951). Seven subjects presented a variability greater than ±3% in both verification tests compared with the incremental test. The same-day verification test decreased the exercise tolerance (240 ± 38 vs. 310 ± 36 s) compared with TLIM-DIFF (P < 0.05). In conclusion, the incremental protocol is capable of measuring maximal oxygen uptake because similar values were observed in comparison with verification tests. Although the need for the verification phase is questionable, the additional tests are useful to evaluate individual variability. Novelty Step incremental test is capable of measuring maximal oxygen uptake with similar values during TLIM on the same or different day. Although the necessity of the verification phase is questionable, it can allow the determination of variability in maximal oxygen uptake.

scholarly journals The individual time trial as an optimal control problem

2017 ◽  
Vol 231 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Jenny de Jong ◽  
Robbert Fokkink ◽  
Geert Jan Olsder ◽  
AL Schwab
Keyword(s):  
Optimal Control ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Power Output ◽  
Anaerobic Power ◽  
Singular Control ◽  
Time Trial ◽  
Cycling Time Trial ◽  
The Individual ◽  
Cycling Time

In a cycling time trial, the rider needs to distribute his power output optimally to minimize the time between start and finish. Mathematically, this is an optimal control problem. Even for a straight and flat course, its solution is non-trivial and involves a singular control, which corresponds to a power that is slightly above the aerobic level. The rider must start at full anaerobic power to reach an optimal speed and maintain that speed for the rest of the course. If the course is flat but not straight, then the speed at which the rider can round the bends becomes crucial.

The Influence of Blood Removal on Pacing During a 4-Minute Cycling Time Trial

2017 ◽  
Vol 12 (8) ◽  
pp. 1085-1092
Author(s):  
Nathan G. Lawler ◽  
Chris R. Abbiss ◽  
Aaron Raman ◽  
Timothy J. Fairchild ◽  
Garth L. Maker ◽  
...  
Keyword(s):  
Power Output ◽  
Average Power ◽  
Time Trial ◽  
Energy Contribution ◽  
Cycling Time Trial ◽  
Baseline Testing ◽  
Average Power Output ◽  
Rate Of Decline ◽  
Aerobic And Anaerobic ◽  
Cycling Time

Purpose:To examine the influence of manipulating aerobic contribution after whole-blood removal on pacing patterns, performance, and energy contribution during self-paced middle-distance cycling.Methods:Seven male cyclists (33 ± 8 y) completed an incremental cycling test followed 20 min later by a 4-min self-paced cycling time trial (4MMP) on 6 separate occasions over 42 d. The initial 2 sessions acted as familiarization and baseline testing, after which 470 mL of blood was removed, with the remaining sessions performed 24 h, 7 d, 21 d, and 42 d after blood removal. During all 4MMP trials, power output, oxygen uptake, and aerobic and anaerobic contribution to power were determined.Results:4MMP average power output significantly decreased by 7% ± 6%, 6% ± 8%, and 4% ± 6% at 24 h, 7 d, and 21 d after blood removal, respectively. Compared with baseline, aerobic contribution during the 4MMP was significantly reduced by 5% ± 4%, 4% ± 5%, and 4% ± 10% at 24 h, 7 d, and 21 d, respectively. The rate of decline in power output on commencement of the 4MMP was significantly attenuated and was 76% ± 20%, 72% ± 24%, and 75% ± 35% lower than baseline at 24 h, 21 d, and 42 d, respectively.Conclusion:Removal of 470 mL of blood reduces aerobic energy contribution, alters pacing patterns, and decreases performance during self-paced cycling. These findings indicate the importance of aerobic energy distribution during self-paced middle-distance events.

scholarly journals Maximal power output during incremental cycling test is dependent on the curvature constant of the power–time relationship

2015 ◽  
Vol 40 (9) ◽  
pp. 895-898 ◽  
Author(s):  
Kristopher Mendes Souza ◽  
Ricardo Dantas de Lucas ◽  
Paulo Cesar do Nascimento Salvador ◽  
Luiz Guilherme Antonacci Guglielmo ◽  
Renato Aparecido Corrêa Caritá ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Maximal Power ◽  
Maximal Power Output ◽  
Physically Active ◽  
Cycling Test ◽  
Time Relationship ◽  
Constant Work Rate ◽  
Male Subjects

The aim of this study was to investigate whether the maximal power output (Pmax) during an incremental test was dependent on the curvature constant (W′) of the power–time relationship. Thirty healthy male subjects (maximal oxygen uptake = 3.58 ± 0.40 L·min−1) performed a ramp incremental cycling test to determine the maximal oxygen uptake and Pmax, and 4 constant work rate tests to exhaustion to estimate 2 parameters from the modeling of the power–time relationship (i.e., critical power (CP) and W′). Afterwards, the participants were ranked according to their magnitude of W′. The median third was excluded to form a high W′ group (HIGH, n = 10), and a low W′ group (LOW, n = 10). Maximal oxygen uptake (3.84 ± 0.50 vs. 3.49 ± 0.37 L·min−1) and CP (213 ± 22 vs. 200 ± 29 W) were not significantly different between HIGH and LOW, respectively. However, Pmax was significantly greater for the HIGH (337 ± 23 W) than for the LOW (299 ± 40 W). Thus, in physically active individuals with similar aerobic parameters, W′ influences the Pmax during incremental testing.

scholarly journals Correlation of maximal respiratory exchange ratio with anaerobic power and maximal oxygen uptake in anaerobic trained athletes

2021 ◽  
Vol 25 (4) ◽  
pp. 261-266
Author(s):  
Selcen Korkmaz Eryılmaz ◽  
Metin Polat
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Peak Power ◽  
Respiratory Exchange Ratio ◽  
Anaerobic Power ◽  
Anaerobic Capacity ◽  
Fatigue Index ◽  
Mean Power ◽  
Running Speed ◽  
The Relationship

Background and Study Aim. The respiratory exchange ratio (RER) is the ratio of the amount of carbon dioxide produced (VCO2) to the amount of oxygen uptake (VO2) is important. It indirectly informs about the predominant metabolic pathway to provide the energy needed during exercise. The relationship of maximal RER with aerobic and anaerobic capacity in athletes remains unclear. The purpose of this study was to investigate the relationship between maximal RER and anaerobic power and maximal oxygen uptake (VO2max) in anaerobic trained athletes. Material and Methods. Thirteen male alpine skiers (age 18.1 ± 3.1 years) competing in national and international competitions participated in the study. Athletes first performed an incremental treadmill run test to determine their VO2max (ml/kg/min), maximal RER (VCO2 / VO2) and maximal running speed (km/h). After 48 hours, the athletes performed the Wingate anaerobic test to determine peak power, mean power, minimum power, and fatigue index. Pearson correlation coefficients were used to examine the relations between variables. Results. Maximal RER was positively correlated with peak power (r = 0.587, p < 0.035), mean power (r = 0.656, p < 0.015) and minimum power (r = 0.674, p < 0.012). Maximal RER did not significantly correlate with fatigue index (p > 0.05). Maximal RER was negatively correlated with the VO2max (r = – 0.705, p < 0.007) and maximal running speed (r = – 0.687, p < 0.01). Conclusions. Maximal RER may be useful for evaluating anaerobic capacity in anaerobic-trained athletes. Measuring the maximal RER values of athletes during incremental exercise may provide information about physiological adaptations in response to physical training.

scholarly journals Acute administration of high doses of taurine does not substantially improve high-intensity running performance and the effect on maximal accumulated oxygen deficit is unclear

2016 ◽  
Vol 41 (5) ◽  
pp. 498-503 ◽  
Author(s):  
Fabio Milioni ◽  
Elvis de Souza Malta ◽  
Leandro George Spinola do Amaral Rocha ◽  
Camila Angélica Asahi Mesquita ◽  
Ellen Cristini de Freitas ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Exercise Intensity ◽  
Maximal Oxygen Uptake ◽  
High Intensity ◽  
Treadmill Running ◽  
Oxygen Deficit ◽  
Time To Exhaustion ◽  
Acute Administration ◽  
Running Performance ◽  
Accumulated Oxygen Deficit

The aim of the present study was to investigate the effects of acute administration of taurine overload on time to exhaustion (TTE) of high-intensity running performance and alternative maximal accumulated oxygen deficit (MAODALT). The study design was a randomized, placebo-controlled, crossover design. Seventeen healthy male volunteers (age: 25 ± 6 years; maximal oxygen uptake: 50.5 ± 7.6 mL·kg−1·min−1) performed an incremental treadmill-running test until voluntary exhaustion to determine maximal oxygen uptake and exercise intensity at maximal oxygen uptake. Subsequently, participants completed randomly 2 bouts of supramaximal treadmill-running at 110% exercise intensity at maximal oxygen uptake until exhaustion (placebo (6 g dextrose) or taurine (6 g) supplementation), separated by 1 week. MAODALT was determined using a single supramaximal effort by summating the contribution of the phosphagen and glycolytic pathways. When comparing the results of the supramaximal trials (i.e., placebo and taurine conditions) no differences were observed for high-intensity running TTE (237.70 ± 66.00 and 277.30 ± 40.64 s; p = 0.44) and MAODALT (55.77 ± 8.22 and 55.06 ± 7.89 mL·kg−1; p = 0.61), which seem to indicate trivial and unclear differences using the magnitude-based inferences approach, respectively. In conclusion, acute 6 g taurine supplementation before exercise did not substantially improve high-intensity running performance and showed an unclear effect on MAODALT.

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