Alexis R. Mauger

Influence of feedback and prior experience on pacing during a 4-km cycle time trial.

PURPOSE To determine the importance of distance knowledge, distance feedback, and prior experience on the setting of a pacing strategy. METHODS Eighteen well-trained male cyclists were randomly assigned to a control (CON) group or an experimental (EXP) group and performed four consecutive 4-km time trials (TT), separated by a 17-min recovery. The CON group received prior knowledge of distance to be cycled and received distance feedback throughout each TT; the EXP group received neither but knew that each TT was of the same distance. RESULTS The EXP group was significantly slower than the CON group to complete TT1 (367.4 +/- 21 vs 409.4 +/- 45.5 s, P < 0.001). Differences between groups in completion time reduced over successive TT (CON TT4 = 373.9 +/- 20 s vs EXP TT4 = 373.8 +/- 14.4 s), shown by a significant linear contrast (F1,16 = 12.39, P < 0.0005). Mean speed and power output also showed significantly reduced differences between groups over successive TT (P < 0.0005). However, peak power output showed no such convergence between groups over TT. End blood lactate was significantly different between groups in TT1, but differences between groups converged with successive TT. CONCLUSION The progressively improving completion times in the EXP group show that distance feedback is not essential in developing an appropriate pacing strategy. Prior experience of an unknown distance appears to allow the creation of an internal, relative distance that is used to establish a pacing strategy.

Influence of acetaminophen on performance during time trial cycling

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 (t(12) = 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.

A new VO2max protocol allowing self-pacing in maximal incremental exercise

Introduction The traditional maximal oxygen uptake (VO2max) protocol has received criticism for being an unnatural form of exercise, lacking ecological validity and producing different VO2max responses depending on protocol duration and work rate increments. Purpose The purpose of this investigation was to design and test a new VO2max protocol allowing subjects to self-pace their work rate while maintaining an incremental test structure. Methods 16 untrained subjects completed a self-paced VO2max protocol (SPV) and a traditional VO2max test in a counter-balanced, crossover design. The SPV used incremental ‘clamps’ of ratings of perceived exertion (RPE) over 5 × 2-min stages (10-min duration) while allowing subjects to vary their power output (PO) according to the required RPE. Results Subjects achieved significantly higher (p < 0.05) VO2max values (40 ± 10 ml/kg/min vs 37 ± 8 ml/kg/min) and peak POs (273 ± 58 W vs 238 ± 55 W) in the SPV. Higher VO2max values were observed in the SPV even when a plateau (VO2–time slope <0.05 l/min) occurred in the traditional test. No differences were found between any other measured physiological variable (minute ventilation, heart rate and respiratory exchange ratio). Conclusions As SPV is a closed-loop test (10-min duration) that allows subjects to self-pace their work rate, it disregards the need for experimenters to estimate starting work rates, stage lengths and increments in order to bring about volitional exhaustion in 8–10 min. The observation that the SPV may also elicit higher VO2max values than a traditional test warrants further research in this area and its consideration as standard measure to elicit VO2max.

The efficacy of the self-paced V̇O2max test to measure maximal oxygen uptake in treadmill running.

The novel self-paced, cycle-based maximal oxygen uptake (V̇O2max) test (SPV) has been shown to produce higher V̇O2max values than standard graded exercise test (GXT) protocols. This study sought to ascertain whether these observations would also be apparent in a self-paced, treadmill-based test design. Fourteen trained male runners performed a standard GXT on a motorised treadmill and a self-paced V̇O2max test on a nonmotorised treadmill in a counter-balanced design. The GXT included a plateau verification and was designed to last between 8 and 12 min. The self-paced test included 5 × 2 min stages and allowed participants to set their own running speed based on fixed increments in rating of perceived exertion. Significantly higher V̇O2max values (t[13] = 3.71, p = 0.003) were achieved in the self-paced test (64.4 ± 7.3 mL · kg(-1) · min(-1)) compared with the GXT (61.3 ± 7.3 mL · kg(-1) · min(-1)), and 13 of the 14 participants achieved the same or higher V̇O2max values in the self-paced test. Higher (p = 0.01) maximum heart rates were observed in the GXT (191 ± 10 beats · min(-1) vs. 187 ± 7 beats · min(-1)), but no differences were observed in any other recorded variables. The self-paced V̇O2max test may provide a more valid means of measuring V̇O2max than the GXT and suggests that a V̇O2 plateau during a GXT does not always signify achievement of a definitive V̇O2max. These results provide further support that self-paced V̇O2max testing produces higher values for maximal oxygen uptake.

Conventional testing methods produce submaximal values of maximum oxygen consumption

Background This study used a novel protocol to test the hypothesis that a plateau in oxygen consumption (VO2max) during incremental exercise testing to exhaustion represents the maximal capacity of the cardiovascular system to transport oxygen. Methods Twenty-six subjects were randomly divided into two groups matched by their initial VO2max. On separate days, the reverse group performed (i) an incremental uphill running test on a treadmill (INC1) plus verification test (VER) at a constant workload 1 km h−1 higher than the last completed stage in INC1; (ii) a decremental test (DEC) in which speed started as same as the VER but was reduced progressively and (iii) a final incremental test (INCF). The control group performed only INC on the same days that the reverse group was tested. Results VO2max remained within 0.6 ml kg−1 min−1 across the three trials for the control group (p=0.93) but was 4.4% higher during DEC compared with INC1 (63.9±3.8 vs 61.2±4.8 ml kg−1 min−1, respectively, p=0.004) in the reverse group, even though speed at VO2max was lower (14.3±1.1 vs 16.2±0.7 km h−1 for DEC and INC1, respectively, p=0.0001). VO2max remained significantly higher during INCF (63.6±3.68 ml kg−1 min−1, p=0.01), despite an unchanged exercise time between INC1 and INCF. Conclusion These findings go against the concept that a plateau in oxygen consumption measured during the classically described INC and VER represents a systemic limitation to oxygen use. The reasons for a higher VO2 during INCF following the DEC test are unclear.

The Effect of Non-Contingent and Accurate Performance Feedback on Pacing and Time Trial Performance in 4 km Track Cycling

Objective To determine whether the provision of comparative performance feedback during 4 km track cycling affects completion time. Design Five highly trained male cyclists first performed a baseline (BL) 4-km time trial (TT) on a velodrome track, followed by two further randomised 4-km TT, during which riders received either correct (COR) or non-contingent (FAL) feedback based on their BL performance. Results Participants completed the COR TT in a significantly faster time (t4=−3.10, p<0.05) than the FAL TT (341 (8) s vs 350 (12) s). Over the TT, a significant difference in mean speed was apparent between the two conditions (F15,60=1.95, p<0.05) on the second (t4=4.71, p<0.05), 15th (t4=3.45, p<0.05) and final lap (t4=3.30, p<0.05). Conclusion The significant difference in completion time and pacing strategy between the two conditions suggests that accurate, comparative performance feedback is beneficial to performance, especially during the start and end of an exercise bout. The results support the previously unfounded assumption that performance feedback is advantageous during exercise and highlights the importance of an athletes support team during an event.

Acute acetaminophen (paracetamol) ingestion improves time to exhaustion during exercise in the heat

•  What is the central question of this study? Acetaminophen (paracetamol) is an analgesic and antipyretic, which has been shown to improve self‐paced cycling performance through a reduction in pain. We sought to ascertain whether acetaminophen could improve time to exhaustion during exercise in the heat through its antipyretic action. •  What is the main finding and its importance? An acute dose of acetaminophen allowed participants to cycle significantly longer in hot conditions by a mean of 4 min (+17%). This was accompanied by significantly lower core, skin and body temperature, and participants found the exercise less of a thermal strain. These findings suggest that acetaminophen may reduce the thermal challenge of exercise in hot conditions.

Fatigue is a pain—the use of novel neurophysiological techniques to understand the fatigue-pain relationship

Fatigue can be defined as any exercise-induced reduction in the ability to exert muscle force or power, regardless of whether or not the task can be sustained (Gandevia, 2001). There is no doubt that in sports performance where time to completion is the outcome measure, the management of fatigue is probably the determining factor of success. However, in exercise physiology, interventions and mechanisms have traditionally be measured using time to exhaustion tasks, where “the point of fatigue” occurs at task failure. The problem with this approach is that in sports performance, tasks are self-paced, and therefore in a successful performance, task failure (and thus the traditional concept of fatigue) never actually occurs. Therefore, which mechanisms govern fatigue in task failure, and which mechanisms govern work rate regulation (and thus the management of the process of fatigue) are very different constructs, which should not be used synonymously.

The Self-Paced VO2max Test to Assess Maximal Oxygen Uptake in Highly Trained Runners

PURPOSE The novel self-paced maximal-oxygen-uptake (VO2max) test (SPV) may be a more suitable alternative to traditional maximal tests for elite athletes due to the ability to self-regulate pace. This study aimed to examine whether the SPV can be administered on a motorized treadmill. METHODS Fourteen highly trained male distance runners performed a standard graded exercise test (GXT), an incline-based SPV (SPVincline), and a speed-based SPV (SPVspeed). The GXT included a plateau-verification stage. Both SPV protocols included 5×2-min stages (and a plateau-verification stage) and allowed for self-pacing based on fixed increments of rating of perceived exertion: 11, 13, 15, 17, and 20. The participants varied their speed and incline on the treadmill by moving between different marked zones in which the tester would then adjust the intensity. RESULTS There was no significant difference (P=.319, ES=0.21) in the VO2max achieved in the SPVspeed (67.6±3.6 mL·kg(-1)·min(-1), 95%CI=65.6-69.7 mL·kg(-1)·min(-1)) compared with that achieved in the GXT (68.6±6.0 mL·kg(-1)·min(-1), 95%CI=65.1-72.1 mL·kg(-1)·min(-1)). Participants achieved a significantly higher VO2max in the SPVincline (70.6±4.3 mL·kg(-1)·min(-1), 95%CI=68.1-73.0 mL·kg(-1)·min(-1)) than in either the GXT (P=.027, ES=0.39) or SPVspeed (P=.001, ES=0.76). CONCLUSIONS The SPVspeed protocol produces VO2max values similar to those obtained in the GXT and may represent a more appropriate and athlete-friendly test that is more oriented toward the variable speed found in competitive sport.

The Reliability and Validity of a Soccer-Specific Nonmotorised Treadmill Simulation (Intermittent Soccer Performance Test)

Abstract Aldous, JWF, Akubat, I, Chrismas, BCR, Watkins, SL, Mauger, AR, Midgley, AW, Abt, G, and Taylor, L. The reliability and validity of a soccer-specific nonmotorised treadmill simulation (intermittent soccer performance test). J Strength Cond Res 28(7): 1971–1980, 2014—This study investigated the reliability and validity of a novel nonmotorised treadmill (NMT)-based soccer simulation using a novel activity category called a “variable run” to quantify fatigue during high-speed running. Twelve male University soccer players completed 3 familiarization sessions and 1 peak speed assessment before completing the intermittent soccer performance test (iSPT) twice. The 2 iSPTs were separated by 6–10 days. The total distance, sprint distance, and high-speed running distance (HSD) were 8,968 ± 430 m, 980 ± 75 m and 2,122 ± 140 m, respectively. No significant difference (p > 0.05) was found between repeated trials of the iSPT for all physiological and performance variables. Reliability measures between iSPT1 and iSPT2 showed good agreement (coefficient of variation: <4.6%; intraclass correlation coefficient: >0.80). Furthermore, the variable run phase showed HSD significantly decreased (p ⩽ 0.05) in the last 15 minutes (89 ± 6 m) compared with the first 15 minutes (85 ± 7 m), quantifying decrements in high-speed exercise compared with the previous literature. This study validates the iSPT as a NMT-based soccer simulation compared with the previous match-play data and is a reliable tool for assessing and monitoring physiological and performance variables in soccer players. The iSPT could be used in a number of ways including player rehabilitation, understanding the efficacy of nutritional interventions, and also the quantification of environmentally mediated decrements on soccer-specific performance.