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Nicolas Fabre, Stéphane Perrey, Loïc Arbez and Jean-Denis Rouillon

Purpose:

This study aimed (1) to determine whether paced breathing (synchronization of the expiration phase with poling time) would reduce the metabolic rate and dictate a lower rate of perceived exertion (RPE) than does spontaneous breathing and (2) to analyze the effects of paced breathing on poling forces and stride-mechanics organization during roller-ski skating exercises.

Methods:

Thirteen well-trained cross-country skiers performed 8 submaximal roller-skiing exercises on a motorized driven treadmill with 4 modes of skiing (2 skating techniques, V2 and V2A, at 2 exercise intensities) by using 2 patterns of breathing (unconscious vs conscious). Poling forces and stride-mechanics organization were measured with a transducer mounted in ski poles. Oxygen uptake (VO2) was continuously collected. After each bout of exercise RPE was assessed by the subject.

Results:

No difference was observed for VO2 between spontaneous and paced breathing conditions, although RPE was lower with paced breathing (P < .05). Upper-limb cycle time and recovery time were significantly (P < .05) increased by paced breathing during V2A regardless of the exercise intensity, but no changes for poling time were observed. A slight trend of increased peak force with paced breathing was observed (P = .055).

Conclusion:

The lack of a marked effect of paced breathing on VO2 and some biomechanical variables could be explained by the extensive experience of our subjects in cross-country skiing.

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Britton W. Brewer, Tina M. Manos, Anne V. McDevitt, Allen E. Cornelius and Judy L. Van Raalte

Two studies tested the hypothesis that exertional trend influences perceived aversiveness of an exercise bout. In Study 1, participants (64 women and 26 men) read descriptions of 8 fictitious people’s ratings of perceived exertion during exercise sessions on a stationary bicycle, including a 15-min session with a pattern of increasing exertion and a 20-min session with a pattern of exertion identical to the 15-min session with the addition of a 5-min period of reduced exertion at the end. Despite a greater overall workload, the 20-min session was perceived as significantly less aversive than the 15-min session. In Study 2, participants (11 women and 9 men) completed 15- and 20-min sessions on a cycle ergometer with the same basic exertional patterns as in Study 1. Ratings of the aversiveness of the 2 sessions did not differ significantly, despite the difference in duration. Results demonstrate that adding a period of reduced exertion attenuates the perceived aversiveness of a bout of exercise.

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Martin J. Barwood, Jo Corbett, Christopher R.D. Wagstaff, Dan McVeigh and Richard C. Thelwell

Purpose:

Unpleasant physical sensations during maximal exercise may manifest themselves as negative cognitions that impair performance, alter pacing, and are linked to increased rating of perceived exertion (RPE). This study examined whether motivational self-talk (M-ST) could reduce RPE and change pacing strategy, thereby enhancing 10-km time-trial (TT) cycling performance in contrast to neutral self-talk (N-ST).

Methods:

Fourteen men undertook 4 TTs, TT1–TT4. After TT2, participants were matched into groups based on TT2 completion time and underwent M-ST (n = 7) or N-ST (n = 7) after TT3. Performance, power output, RPE, and oxygen uptake (VO2) were compared across 1-km segments using ANOVA. Confidence intervals (95%CI) were calculated for performance data.

Results:

After TT3 (ie, before intervention), completion times were not different between groups (M-ST, 1120 ± 113 s; N-ST, 1150 ± 110 s). After M-ST, TT4 completion time was faster (1078 ± 96 s); the N-ST remained similar (1165 ± 111 s). The M-ST group achieved this through a higher power output and VO2 in TT4 (6th–10th km). RPE was unchanged. CI data indicated the likely true performance effect lay between 13- and 71-s improvement (TT4 vs TT3).

Conclusion:

M-ST improved endurance performance and enabled a higher power output, whereas N-ST induced no change. The VO2 response matched the increase in power output, yet RPE was unchanged, thereby inferring a perceptual benefit through M-ST. The valence and content of self-talk are important determinants of the efficacy of this intervention. These findings are primarily discussed in the context of the psychobiological model of pacing.

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Daniel J. Peart, Andy Hensby and Matthew P. Shaw

The purpose of this study was to compare markers of hydration during submaximal exercise and subsequent time trial performance when consuming water (PW) or coconut water (CW). There was also a secondary aim to assess the palatability of CW during exercise and voluntary intake during intense exercise. 10 males (age 27.9 ± 4.9 years, body mass 78.1 ± 10.1kg, average max minute power 300.2 ± 28.2W) completed 60-min of submaximal cycling followed by a 10-km time trial on two occasions. During these trials participants consumed either PW or CW in a randomized manner, drinking a 250 ml of the assigned drink between 10–15 min, 25–30 min and 40–45 min, and then drinking ad libitum from 55-min until the end of the time trial. Body mass and urine osmolality were recorded preexercise and then after 30-min, 60-min, and post time trial. Blood glucose, lactate, heart rate, rate of perceived exertion (RPE; 6–20) and ratings of thirst, sweetness, nausea, fullness and stomach upset (1 =very low/none, 5= very high) were recorded during each drink period. CW did not significantly improve time trial performance compared with PW (971.4 ± 50.5 and 966.6 ± 44.8 s respectively; p = .698) and there was also no significant differences between trials for any of the physiological variables measured. However there were subjective differences between the beverages for taste, resulting in a significantly reduced volume of voluntary intake in the CW trial (115 ± 95.41 ml and 208.7 ± 86.22 ml; p < .001).

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Gi Broman, Miguel Quintana, Margareta Engardt, Lennart Gullstrand, Eva Jansson and Lennart Kaijser

The aim of the study was to examine submaximal and maximal physiological responses and perceived exertion during deep-water running with a vest compared with the responses during treadmill running in healthy elderly women. Eleven healthy women 70 ± 2 years old participated. On two different occasions they performed a graded maximal exercise test on a treadmill on land and a graded maximal exercise test in water wearing a vest. At maximal work the oxygen uptake was 29% lower (p < .05), the heart rate was 8% lower (p < .05), and the ventilation was 16% lower (p < .05) during deep-water running than during treadmill running. During submaximal absolute work the heart rate was higher during deep-water running than during treadmill running for the elderly women. The participants had lower maximal oxygen uptake, heart rate, ventilation, respiratory-exchange ratio, and rate of perceived exertion during maximal deep-water running with a vest than during maximal treadmill running. These responses were, however, higher during submaximal deep-water running than during treadmill running.

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Stephen Seiler and Øystein Sylta

The purpose of this study was to compare physiological responses and perceived exertion among well-trained cyclists (n = 63) performing 3 different high-intensity interval-training (HIIT) prescriptions differing in work-bout duration and accumulated duration but all prescribed with maximal session effort. Subjects (male, mean ± SD 38 ± 8 y, VO2peak 62 ± 6 mL · kg–1 · min–1) completed up to 24 HIIT sessions over 12 wk as part of a training-intervention study. Sessions were prescribed as 4 × 16, 4 × 8, or 4 × 4 min with 2-min recovery periods (8 sessions of each prescription, balanced over time). Power output, HR, and RPE were collected during and after each work bout. Session RPE was reported after each session. Blood lactate samples were collected throughout the 12 wk. Physiological and perceptual responses during >1400 training sessions were analyzed. HIIT sessions were performed at 95% ± 5%, 106% ± 5%, and 117% ± 6% of 40-min time-trial power during 4 × 16-, 4 × 8-, and 4 × 4-min sessions, respectively, with peak HR in each work bout averaging 89% ± 2%, 91% ± 2%, and 94% ± 2% HRpeak. Blood lactate concentrations were 4.7 ± 1.6, 9.2 ± 2.4, and 12.7 ± 2.7 mmol/L. Despite the common prescription of maximal session effort, RPE and sRPE increased with decreasing accumulated work duration (AWD), tracking relative HR. Only 8% of 4 × 16-min sessions reached RPE 19–20, vs 61% of 4 × 4-min sessions. The authors conclude that within the HIIT duration range, performing at “maximal session effort” over a reduced AWD is associated with higher perceived exertion both acutely and postexercise. This may have important implications for HIIT prescription choices.

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Todd A. Astorino, Michael N. Terzi, Daniel W. Roberson and Timothy R. Burnett

Caffeine has been shown to reduce leg-muscle pain during submaximal cycle ergometry, as well as in response to eccentric exercise. However, less is known about its analgesic properties during non-steadystate, high-intensity exercise. The primary aim of this study was to examine the effect of 2 doses of caffeine on leg pain and rating of perceived exertion (RPE) during repeated bouts of high-intensity exercise. Fifteen active men (age 26.4 ± 3.9 yr) completed 2 bouts of 40 repetitions of “all-out” knee extension and flexion of the dominant leg at a contraction velocity equal to 180°/s. Before each trial, subjects abstained from caffeine intake and intense exercise for 48 hr. Over 3 days separated by 48 hr, subjects ingested 1 of 3 treatments (5 mg/kg or 2 mg/kg of anhydrous caffeine or placebo) in a randomized, single-blind, counterbalanced, crossover design. Leg-muscle pain and RPE were assessed during and after exercise using established categorical scales. Across all treatments, pain perception was significantly increased (p < .05) during exercise, as well as from Bout 1 to 2, yet there was no effect (p > .05) of caffeine on pain perception or RPE. Various measures of muscle function were improved (p < .05) with a 5-mg/kg caffeine dose vs. the other treatments. In the 5-mg/kg trial, it is plausible that subjects were able to perform better with similar levels of pain perception and exertion.

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Daniel Castillo, Matthew Weston, Shaun J. McLaren, Jesús Cámara and Javier Yanci

The aims of this study were to describe the internal and external match loads (ML) of refereeing activity during official soccer matches and to investigate the relationship among the methods of ML quantification across a competitive season. A further aim was to examine the usefulness of differential perceived exertion (dRPE) as a tool for monitoring internal ML in soccer referees. Twenty field referees (FRs) and 43 assistant referees (ARs) participated in the study. Data were collected from 30 competitive matches (FR = 20 observations, AR = 43 observations) and included measures of internal (Edwards’ heart-rate-derived training impulse [TRIMPEDW]) ML, external (total distance covered, distance covered at high speeds, and player load) ML, and ML differentiated ratings of perceived respiratory (sRPEres) and leg-muscle (sRPEmus) exertion. Internal and external ML were all greater for FRs than for ARs (–19.7 to –72.5), with differences ranging from very likely very large to most likely extremely large. The relationships between internal-ML and external-ML indicators were, in most cases, unclear for FR (r < .35) and small to moderate for AR (r < .40). The authors found substantial differences between RPEres and RPEmus scores in both FRs (0.6 AU; ±90% confidence limits 0.4 AU) and ARs (0.4; ±0.3). These data demonstrate the multifaceted demands of soccer refereeing and thereby highlight the importance of monitoring both internal and external ML. Moreover, dRPE represents distinct dimensions of effort and may be useful in monitoring soccer referees’ ML during official matches.

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Christopher D. Black and Patrick J. O’Connor

Ginger has known hypoalgesic and anti-inflammatory properties. The effects of an oral dose of ginger on quadriceps muscle pain, rating of perceived exertion (RPE), and recovery of oxygen consumption were examined during and after moderateintensity cycling exercise. Twenty-five college-age participants ingested a 2-g dose of ginger or placebo in a double-blind, crossover design and 30 min later completed 30 min of cycling at 60% of VO2peak. Quadriceps muscle pain, RPE, work rate, heart rate (HR), and oxygen uptake (VO2) were recorded every 5 min during exercise, and HR and VO2 were recorded for 20 min after exercise. Compared with placebo, ginger had no clinically meaningful or statistically significant effect on perceptions of muscle pain, RPE, work rate, HR, or VO2 during exercise. Recovery of VO2 and HR after the 30-min exercise bout followed a similar time course in the ginger and placebo conditions. The results were consistent with related findings showing that ingesting a large dose of aspirin does not acutely alter quadriceps muscle pain during cycling, and this suggests that prostaglandins do not play a large role in this type of exercise-induced skeletal-muscle pain. Ginger consumption has also been shown to improve VO2 recovery in an equine exercise model, but these results show that this is not the case in humans.

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Erling A. Algrøy, Ken J. Hetlelid, Stephen Seiler and Jørg I. Stray Pedersen

Purpose:

This study was designed to quantify the daily distribution of training intensity in a group of professional soccer players in Norway based on three different methods of training intensity quantification.

Methods:

Fifteen male athletes (age, 24 ± 5 y) performed treadmill test to exhaustion to determine heart rate and VO2 corresponding to ventilatory thresholds (VT1, VT2), maximal oxygen consumption (VO2max) and maximal heart rate. VT1 and VT2 were used to delineate three intensity zones based on heart rate. During a 4 wk period in the preseason (N = 15), and two separate weeks late in the season (N = 11), all endurance and on-ball training sessions (preseason: N = 378, season: N= 78) were quantified using continuous heart rate registration and session rating of perceived exertion (sRPE). Three different methods were used to quantify the intensity distribution: time in zone, session goal and sRPE.

Results:

Intensity distributions across all sessions were similar when based on session goal or by sRPE. However, intensity distribution based on heart rate cut-offs from standardized testing was significantly different (time in zone).

Conclusions:

Our findings suggest that quantifying training intensity by using heart rate based total time in zone is not valid for describing the effective training intensity in soccer. The results also suggest that the daily training intensity distribution in this representative group of high level Norwegian soccer players is organized after a pattern where about the same numbers of training sessions are performed in low lactate, lactate threshold, and high intensity training zones.