Repeated muscle damage blunts the increase in heat strain during subsequent exercise heat stress

Dolci, Alberto; Fortes, Matthew B.; Walker, Francis; Haq, Adnan; Riddle, Tara M.; Walsh, Neil P.

doi:10.1007/s00421-015-3143-7

Cited by 11 publications

(18 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Byrnes et al [193] reported smaller increases in plasma CK, plasma myoglobin and DOMS up to 48 h after a second DR bout when two 30 min bouts (slope: − 10%; intensity: 170 beats min −1 of heart rate recorded on level grade) were separated by 3-, 6-and 9-weeks. Further studies corroborated these results by reporting a lower leakage and/ or a faster clearance of intracellular muscle proteins in the blood [46,63,67,85,92,121,141,143,165,181,185], lower DOMS [63,68,85,92,121,141,143,185,192,196,197] and enhanced recovery of MVC force/torque [63] after a second DR bout (Table 1 and Fig. 3b).…”

Section: Prior Exposure To Downhill Runningsupporting

confidence: 60%

Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review

et al. 2020

View full text Add to dashboard Cite

Downhill running (DR) is a whole-body exercise model that is used to investigate the physiological consequences of eccentric muscle actions and/or exercise-induced muscle damage (EIMD). In a sporting context, DR sections can be part of running disciplines (off-road and road running) and can accentuate EIMD, leading to a reduction in performance. The purpose of this narrative review is to: (1) better inform on the acute and delayed physiological effects of DR; (2) identify and discuss, using a comprehensive approach, the DR characteristics that affect the physiological responses to DR and their potential interactions; (3) provide the current state of evidence on preventive and in-situ strategies to better adapt to DR. Key findings of this review show that DR may have an impact on exercise performance by altering muscle structure and function due to EIMD. In the majority of studies, EIMD are assessed through isometric maximal voluntary contraction, blood creatine kinase and delayed onset muscle soreness, with DR characteristics (slope, exercise duration, and running speed) acting as the main influencing factors. In previous studies, the median (25th percentile, Q1; 75th percentile, Q3) slope, exercise duration, and running speed were − 12% (− 15%; − 10%), 40 min (30 min; 45 min) and 11.3 km h−1 (9.8 km h−1; 12.9 km h−1), respectively. Regardless of DR characteristics, people the least accustomed to DR generally experienced the most EIMD. There is growing evidence to suggest that preventive strategies that consist of prior exposure to DR are the most effective to better tolerate DR. The effectiveness of in-situ strategies such as lower limb compression garments and specific footwear remains to be confirmed. Our review finally highlights important discrepancies between studies in the assessment of EIMD, DR protocols and populations, which prevent drawing firm conclusions on factors that most influence the response to DR, and adaptive strategies to DR.

show abstract

Section: Prior Exposure To Downhill Runningsupporting

confidence: 60%

Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The current study also observed a reduction in thermal strain (T re −0.3°C) equivalent to that of various heat acclimation regimes (Gibson et al, 2015b; Tyler et al, 2016), and an attenuated perceived muscle soreness (24 h post = +12.2%, 48 h post = −16.5%) response that is indicative of muscle damage (Fridén et al, 1981) from near identical exercise trials [HPC2 HOTDOWN compared to HPC1 HOTDOWN (see Figure 2 and Table 3)]. Together these responses indicate that downhill running models may be able to elicit a beneficial preconditioning effect (Dolci et al, 2015; Tuttle et al, 2015). Given that acute non-damaging exercise heat stress does not improve thermal responses to a greater extent than equivalent temperate condition exercise [Figure 2, (Lee et al, 2014)], the cellular responses to the eccentric muscle action of the damaging downhill running is important.…”

Section: Discussionmentioning

confidence: 94%

The Hsp72 and Hsp90α mRNA Responses to Hot Downhill Running Are Reduced Following a Prior Bout of Hot Downhill Running, and Occur Concurrently within Leukocytes and the Vastus Lateralis

et al. 2017

View full text Add to dashboard Cite

The leukocyte heat shock response (HSR) is used to determine individual's thermotolerance. The HSR and thermotolerance are enhanced following interventions such as preconditioning and/or acclimation/acclimatization. However, it is unclear whether the leukocyte HSR is an appropriate surrogate for the HSR in other tissues implicated within the pathophysiology of exertional heat illnesses (e.g., skeletal muscle), and whether an acute preconditioning strategy (e.g., downhill running) can improve subsequent thermotolerance. Physically active, non-heat acclimated participants were split into two groups to investigate the benefits of hot downhill running as preconditioning strategy. A hot preconditioning group (HPC; n = 6) completed two trials (HPC1HOTDOWN and HPC2HOTDOWN) of 30 min running at lactate threshold (LT) on −10% gradient in 30°C and 50% relative humidity (RH) separated by 7 d. A temperate preconditioning group (TPC; n = 5) completed 30 min running at LT on a −1% gradient in 20°C and 50% (TPC1TEMPFLAT) and 7 d later completed 30 min running at LT on −10% gradient in 30°C and 50% RH (TPC2HOTDOWN). Venous blood samples and muscle biopsies (vastus lateralis; VL) were obtained before, immediately after, 3, 24, and 48 h after each trial. Leukocyte and VL Hsp72, Hsp90α, and Grp78 mRNA relative expression was determined via RT-QPCR. Attenuated leukocyte and VL Hsp72 (2.8 to 1.8 fold and 5.9 to 2.4 fold; p < 0.05) and Hsp90α mRNA (2.9 to 2.4 fold and 5.2 to 2.4 fold; p < 0.05) responses accompanied reductions (p < 0.05) in physiological strain [exercising rectal temperature (−0.3°C) and perceived muscle soreness (~ −14%)] during HPC2HOTDOWN compared to HPC1HOTDOWN (i.e., a preconditioning effect). Both VL and leukocyte Hsp72 and Hsp90α mRNA increased (p < 0.05) simultaneously following downhill runs and demonstrated a strong relationship (p < 0.01) of similar magnitudes with one another. Hot downhill running is an effective preconditioning strategy which ameliorates physiological strain, soreness and Hsp72 and Hsp90α mRNA responses to a subsequent bout. Leukocyte and VL analyses are appropriate tissues to infer the extent to which the HSR has been augmented.

show abstract

“… 38 In addition to heat stress inducing a GI protective effect, exercise-induced muscle damage (EIMD) has also been shown to blunt heat strain whereby subjects exposed to both exercise heat stress and EIMD up to 14 days after the initial exposure, showed attenuated rises in core temperature and a reduced threshold for the initiation of sweating. 39 These studies indicate that acute heat stress can provide some protection against GI permeability and counteract the leakage of LPS into the internal environment. This protection is likely related to the favorable alterations in heat shock proteins (HSP), 40 which can thereby minimise the otherwise associated inflammatory response.…”

Section: Gi Dysfunction In Exercise Heat Stressmentioning

confidence: 94%

Heat stress, gastrointestinal permeability and interleukin-6 signaling — Implications for exercise performance and fatigue

Vargas

Marino

2016

Temperature

View full text Add to dashboard Cite

Exercise in heat stress exacerbates performance decrements compared to normothermic environments. It has been documented that the performance decrements are associated with reduced efferent drive from the central nervous system (CNS), however, specific factors that contribute to the decrements are not completely understood. During exertional heat stress, blood flow is preferentially distributed away from the intestinal area to supply the muscles and brain with oxygen. Consequently, the gastrointestinal barrier becomes increasingly permeable, resulting in the release of lipopolysaccharides (LPS, endotoxin) into the circulation. LPS leakage stimulates an acute-phase inflammatory response, including the release of interleukin (IL)-6 in response to an increasingly endotoxic environment. If LPS translocation is too great, heat shock, neurological dysfunction, or death may ensue. IL-6 acts initially in a pro-inflammatory manner during endotoxemia, but can attenuate the response through signaling the hypothalamic pituitary adrenal (HPA)-axis. Likewise, IL-6 is believed to be a thermoregulatory sensor in the gut during the febrile response, hence highlighting its role in periphery – to – brain communication. Recently, IL-6 has been implicated in signaling the CNS and influencing perceptions of fatigue and performance during exercise. Therefore, due to the cascade of events that occur during exertional heat stress, it is possible that the release of LPS and exacerbated response of IL-6 contributes to CNS modulation during exertional heat stress. The purpose of this review is to evaluate previous literature and discuss the potential role for IL-6 during exertional heat stress to modulate performance in favor of whole body preservation.

show abstract

Repeated muscle damage blunts the increase in heat strain during subsequent exercise heat stress

Cited by 11 publications

References 52 publications

Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review

Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review

The Hsp72 and Hsp90α mRNA Responses to Hot Downhill Running Are Reduced Following a Prior Bout of Hot Downhill Running, and Occur Concurrently within Leukocytes and the Vastus Lateralis

Heat stress, gastrointestinal permeability and interleukin-6 signaling — Implications for exercise performance and fatigue

Contact Info

Product

Resources

About