Effects of heat exposure in the absence of hyperthermia on power output during repeated cycling sprints

Matsuura, Ryouta; Arimitsu, Takuma; Yunoki, Takahiro; Kimura, T.; Yamanaka, Ryo; Yano, Toshiaki

doi:10.5604/20831862.1125286

Cited by 17 publications

(20 citation statements)

References 23 publications

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“…For example, there was a clear difference in peak power output between INSP (1097 ± 148 W) and MATCH (773 ± 122 W) exercise conditions. In a typical sprint, power output peeks within 1-2 s and progressively declines as the sprint continues (23, 45). When sprints are repeated and separated by incomplete recovery periods, both peak and mean power output gradually decline as fatigue accumulates (1–4, 44).…”

Section: Discussionmentioning

confidence: 99%

“…After a 7-min warm-up consisting of 5 min of unloaded cycling at 60-70 rpm and two 4 s sprints (separated by 1 min), subjects rested for another 2.5 min before the repeated-sprint protocol was initiated. The repeated-sprint protocol was ten consecutive 10 s sprints separated by 30 s passive rest (4, 21–23). Subjects were instructed to give an “all-out” effort for every sprint and verbally encouraged throughout to promote a maximal effort.…”

Section: Methodsmentioning

confidence: 99%

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Muscle oxygenation maintained during repeated sprints despite inspiratory muscle loading

Rodriguez

Townsend

Aughey

et al. 2019

Preprint

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A high work of breathing can compromise limb oxygen delivery during sustained high-intensity exercise. However, it is unclear if the same is true for intermittent sprint exercise. This project examined the addition of an inspiratory load on locomotor muscle tissue reoxygenation during repeated-sprint exercise. Ten healthy males completed three experimental sessions of ten 10 s sprints, separated by 30 s of passive rest on a cycle ergometer. The first two sessions were “all-out’ efforts performed without (CTRL) or with inspiratory loading (INSP) in a randomised and counterbalanced order. The third experimental session (MATCH) consisted of ten 10 s work-matched intervals. Tissue saturation index (TSI) and deoxy-haemoglobin (HHb) of the vastus lateralis and sixth intercostal space was monitored with near-infrared spectroscopy. Vastus lateralis reoxygenation (ΔReoxy) was calculated as the difference from peak HHb (sprint) to nadir HHb (recovery). Total mechanical work completed was similar between INSP and CTRL (effect size: −0.18, 90% confidence limit ±0.43), and differences in vastus lateralis TSI during the sprint (−0.01, ±0.33) and recovery (−0.08, ±0.50) phases were unclear. There was also no meaningful difference in ΔReoxy (0.21, ±0.37). Intercostal HHb was higher in the INSP session compared to CTRL (0.42, ±0.34), whilst the difference was unclear for TSI (−0.01, ±0.33). During MATCH exercise, differences in vastus lateralis TSI were unclear compared to INSP for both sprint (0.10, ±0.30) and recovery (−0.09, ±0.48) phases, and there was no meaningful difference in ΔReoxy (−0.25, ±0.55). Intercostal TSI was higher during MATCH compared to INSP (0.95, ±0.53), whereas HHb was lower (−1.09, ±0.33). The lack of difference in ΔReoxy between INSP and CTRL suggests that for intermittent sprint exercise, the metabolic O2demands of both the respiratory and locomotor muscles can be met. Additionally, the similarity of the MATCH suggests that ΔReoxy was maximal in all exercise conditions.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Muscle oxygenation maintained during repeated sprints despite inspiratory muscle loading

Rodriguez

Townsend

Aughey

et al. 2019

Preprint

View full text Add to dashboard Cite

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“…Evidence of group III/IV muscle afferents reflexively regulating CMO and exercise performance was shown in studies on humans in which 31 P magnetic resonance spectroscopy and muscle afferent block were used 5,15) . In the magnetic resonance spectroscopy study, when the muscle force throughout 5 min of all-out maximal isometric contractions (60 MVCs) converged to 54% MVC, muscle metabolic milieu associated with peripheral fatigue at the end of the all-out contractions was similar to that at task failure of submaximal isometric contraction with 54% MVC 5) .…”

Section: Viewpoint 1: Muscle Afferent Feedback From Active Limb Musclmentioning

confidence: 99%

“…Additionally, Matsuura et al 31) have suggested that changes in cognitive process by heat exposure alter power profiles, but not peak and mean power output, during each cycling sprint in RCS. Therefore, we also must carefully analyze muscle force and power during exercise and take into account the contractile regimen applied to elucidate the interplay between psychological factors and group III/IV muscle afferent feedback.…”

Section: Perspective For Further Researchmentioning

confidence: 99%

Possible contributions of group III/IV muscle afferent feedback to exercise performance

Matsuura

2016

JPFSM

Self Cite

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Exercise performance cannot be maintained indefinitely, i.e., it deteriorates progressively. Traditionally, deterioration of exercise performance has been attributed to failure of peripheral or central functions of muscle activity. However, muscle rigor (i.e., complete failure of muscle contractile function) never occurs and the muscle force exerted never decreases to zero even with sustained maximal muscle contraction. Furthermore, an increase in central motor output to skeletal limb muscles, and consequently, enhancement of exercise performance, is often observed at the end of a time trial race at which impairment of muscle contractile function is greater. These indicate that only failure of peripheral or central function of muscle activity determines exercise performance. However, recent studies have elucidated that group III/IV muscle afferent inputs to the central nervous system have an important role in the regulation or limitation of exercise performance. This article reviewed two viewpoints regarding contributions of group III/IV muscle afferent feedback to regulation of exercise performance.

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“…For instance, a 24 s recovery has been used in protocols of 5 × 6 s (number of trials × duration of each trial) [16]; a 20 and 90 s recovery has been used in 12 × 4 s [18]; a 25, 50 and 100 s recovery in 10 × 5 s [24]; a 30 s recovery in 4 × 10 s [21], 5 × 6 s [9] and 6×6 s protocols [8]; 30 s, 1 and 5 min recovery in 10 × 10 s [27]; and a 40 s recovery in a 10×10 s protocol [17]. Moreover, longer recovery times have ranged from 1.5, 3 and 6 min in 2 × 30 s [3]; 3 min in 10 × 10 s [25]; 4 min in 3 × 30 s [32] and in 6 × 30 s protocols [20]; 5 min in 5 × 60 s [7]; and 20 min in a 3 × 30 s protocol [1].…”

Section: Introductionmentioning

confidence: 99%

Effect of the recovery duration of a repeated sprint exercise on the power output, jumping performance and lactate concentration in pre-pubescent soccer players

Nikolaidis¹,

Knechtle

2016

Biomedical Human Kinetics

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SummaryStudy aim: The aim of the present study was to examine the effect of two different recovery durations (2 min versus 5 min) on the physiological responses (power output, stretch-shortening cycle and lactate concentration) to a 5×6 s repeated cycling sprint exercise protocol in pre-pubescent soccer players. Materials and methods: Twelve male soccer players (age 12.23 ± 0.55 yrs, body mass 43.6 ± 5.5 kg and height 156.1 ± 5.8 cm) performed 5 × 6 s sprints on a cycle ergometer (Ergomedic 874E, Monark, Sweden) against 0.075 times their body mass resistance on two occasions within a week. In one session there was a 2 min recovery and in the other there was a 5 min recovery in a counterbalanced order. A squat jump (SJ) and a countermovement jump (CMJ) were tested before and after each trial, and the eccentric utilisation ratio (EUR) was calculated as CMJ/SJ. Results: No significant trial × recovery interaction was observed in the participants' peak power (p = 0.891, η 2 = 0.118), mean power (p = 0.910, η 2 = 0.106), SJ (p = 0.144, η 2 = 0.630), CMJ (p = 0.616, η 2 = 0.347) and EUR (p = 0.712, η 2 = 0.295). However, a main effect of the trial on the CMJ of a large magnitude (p = 0.006, η 2 = 0.862) was found, in which a higher score was recorded in the third trial than in the first trial (23.3 versus 21.8 cm). No differences were found in the lactate concentrations examined 5 min after the end of the protocol between the two recovery conditions (6.7 ± 1.8 vs. 6.0 ± 1.6 mmol · L -1 , in the 2 and 5 min recovery, respectively, Cohen's d = 0.4). Conclusions:The duration of the passive recovery time (2 min vs. 5 min) in trials of repeated sprints did not induce important changes either to the indices of the jumping performance or to the power output in pre-pubescent participants.

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Effects of heat exposure in the absence of hyperthermia on power output during repeated cycling sprints

Cited by 17 publications

References 23 publications

Muscle oxygenation maintained during repeated sprints despite inspiratory muscle loading

Muscle oxygenation maintained during repeated sprints despite inspiratory muscle loading

Possible contributions of group III/IV muscle afferent feedback to exercise performance

Effect of the recovery duration of a repeated sprint exercise on the power output, jumping performance and lactate concentration in pre-pubescent soccer players

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