The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running

Gavin, James; Myers, Stephen D.; Willems, Mark E. T.

doi:10.1007/s00421-014-3094-4

Cited by 6 publications

(7 citation statements)

References 33 publications

(38 reference statements)

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“…For instance, HR values were significantly higher over time (from +9.3 to +12.6%, Figure 4E ) that might be related to the VO 2 drift but also, to the potential increase of core body temperature experienced during DHR ( Westerlind et al, 1992 ). Time course of RE responses during DHR are relatively scarce in literature ( Dick and Cavanagh, 1987 ; Gavin et al, 2015 ; Westerlind et al, 1992 ), with no reports in trained runners accustomed to eccentric work. In the current investigation, we reported a 5.3–6.8% increase in RE (Figure 4B ) at the end of DHR for both conditions.…”

Section: Discussionmentioning

confidence: 99%

Acute and Delayed Neuromuscular Alterations Induced by Downhill Running in Trained Trail Runners: Beneficial Effects of High-Pressure Compression Garments

et al. 2018

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Introduction: The aim of this study was to examine, from a crossover experimental design, whether wearing high-pressure compression garments (CGs) during downhill treadmill running affects soft-tissue vibrations, acute and delayed responses in running economy (RE), neuromuscular function, countermovement jump, and perceived muscle soreness.Methods: Thirteen male trail runners habituated to regular eccentric training performed two separate 40-min downhill running (DHR, –8.5°) sessions while wearing either CGs (15–20 mmHg for quadriceps and calves) or control garments (CON) at a velocity associated with ∼55% of VO2max, with a set of measurements before (Pre-), after (Post-DHR), and 1 day after (Post-1D). No CGs was used within the recovery phase. Perceived muscle soreness, countermovement jump, and neuromuscular function (central and peripheral components) of knee extensors (KE) and plantar flexors (PF) were assessed. Cardiorespiratory responses (e.g., heart rate, ventilation) and RE, as well as soft-tissue vibrations (root mean square of the resultant acceleration, RMS Ar) for vastus lateralis and gastrocnemius medialis were evaluated during DHR and in Post-1D.Results: During DHR, mean values in RMS Ar significantly increased over time for the vastus lateralis only for the CON condition (+11.6%). RE and cardiorespiratory responses significantly increased (i.e., alteration) over time in both conditions. Post, small to very large central and peripheral alterations were found for KE and PF in both conditions. However, the deficit in voluntary activation (VA) was significantly lower for KE following CGs (–2.4%), compared to CON (–7.9%) conditions. No significant differences in perceived muscle soreness and countermovement jump were observed between conditions whatever the time period. Additionally, in Post-1D, the CGs condition showed reductions in neuromuscular peripheral alterations only for KE (from –4.4 to –7.7%) and perceived muscle soreness scores (–8.3%). No significant differences in cardiorespiratory and RE responses as well as countermovement jump were identified between conditions in Post-1D.Discussion: Wearing high-pressure CGs (notably on KE) during DHR was associated with beneficial effects on soft-tissue vibrations, acute and delayed neuromuscular function, and perceived muscle soreness. The use of CGs during DHR might contribute to the enhanced muscle recovery by exerting an exercise-induced “mechanical protective effect.”

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Section: Discussionmentioning

confidence: 99%

Acute and Delayed Neuromuscular Alterations Induced by Downhill Running in Trained Trail Runners: Beneficial Effects of High-Pressure Compression Garments

et al. 2018

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“…In this sense, internal exercise load has been shown to increase after hard endurance training and competition, representing an augmented internal load and decreased performance [4,6]. This phenomenon could be affected by several psychophysiological and metabolic factors such as rate of perceived exertion (RPE), glycogen depletion, heart rate, dehydration, and exercise-induced muscle damage (EIMD) [3,5,[7][8][9][10]. Therefore, monitoring of internal load may reveal the state of fatigue of an athlete and determine a method for systematically quantifying the exercise dose (i.e., work completed), as well as the individual response to training stimulus [11,12] that might act as a guide in the search for different strategies aimed at decreasing it [11].…”

Section: Introductionmentioning

confidence: 99%

Effects of 120 g/h of Carbohydrates Intake during a Mountain Marathon on Exercise-Induced Muscle Damage in Elite Runners

et al. 2020

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Background—exercise-induced muscle damage (EIMD) and internal exercise load are increased after competing in ultraendurance events such as mountain marathons. Adequate carbohydrate (CHO) intake during exercise optimizes athletic performance and could limit EIMD, reduce internal exercise load and, thus, improve recovery. Therefore, the aim of this study was to research into and compare the effects of high CHO intake (120 g/h) in terms of CHO intake recommendation (90 g/h) and regular CHO intake performed by ultraendurance athletes (60 g/h) during a mountain marathon, on exercise load and EIMD markers (creatine kinase (CK), lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), urea and creatinine). Materials and Methods—a randomized trial was carried out on 20 male elite runners who had previously undertaken nutritional and gut training, and who consumed different CHO dosages according to experimental (EXP—120 g/h), control (CON—90 g/h) and low CHO intake (LOW—60 g/h) groups during a ~4000 m cumulative slope mountain marathon. EIMD markers were analyzed before the race and 24 h afterwards. Internal exercise load was calculated based on rate of perceived exertion (RPE) during and after the marathon event. Results—internal exercise load during the mountain marathon was significantly lower (p = 0.019; η2p = 0.471) in EXP (3805 ± 281 AU) compared to LOW (4688 ± 705 AU) and CON (4692 ± 716 AU). Moreover, results revealed that the EXP group evidenced significantly lower CK (p = 0.019; η2p = 0.373), LDH (p < 0.001; η2p = 0.615) and GOT (p = 0.003; η2p = 0.500) values 24 h after the mountain marathon race compared to LOW and CON. Along these lines, EIMD and exercise load evidenced a close correlation (R = 0.742; p < 0.001). Conclusion: High CHO intake (120 g/h) during a mountain marathon could limit the EIMD observed by CK, LDH and GOT and internal exercise load compared to CHO ingestion of 60 and 90 g/h.

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“…19 Familiarization one involved an incremental cycling trial, with participants cycling (Excalibur Sport 925900, Lode, Groningen, The Netherlands) at ~75 rpm for 3 min at 50 W; Familiarization two involved a submaximal, incremental treadmill run (Pulsar, h/p/cosmos Sports & Medical GmbH, Germany) to establish individual downhill running speed (based upon lactate threshold). 20 The run began at 8 km•h -1 (1% gradient), followed by 1 km•h -1 increments every 4 min until volitional exhaustion (the point at which the participant felt they could no longer continue), or eight stages were completed. Fingertip blood (25µL) samples were drawn from the right index finger, with the pronated hand resting on the treadmill handrail.…”

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confidence: 99%

“…For the LOW condition, participants then cycled at 60% O 2max power (~75 rpm; workload, 181 ± 40 W) until volitional exhaustion (time, 95 ± 13 min; blood glucose reduced by -1.47 ± 0.56 mmol•L -1 (-31.8%)). 20 Biopsy studies have shown this protocol to be effective for depleting muscle glycogen (reduction: total muscle, -77%, type I fibers, -95%, type II fibers, -70%). 21,22 For the NORM condition, participants completed a 2 h seated quiet rest, with no change in blood glucose values.…”

Section: Experimental Sessionsmentioning

confidence: 99%

“…23 The LOW run was performed with decreased blood glucose compared to pre-exhaustive cycling (pre-run, -23.2%; post-run, -26.0%, both P < 0.01); the NORM run was performed with normal blood glucose compared to pre-quiet rest values (pre-run, -2.7%; post-run, 7.3%). 20 Muscle force and soreness measurements were repeated immediately after completion of the run. Session 3 (day 2) was conducted 12 h post-downhill run with the 10 min cycling bout, and then muscle force and soreness measurements repeated in order.…”

Section: Experimental Sessionsmentioning

confidence: 99%

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Cardiorespiratory and metabolic responses after exercise-induced muscle damage: the influence of lowered glycogen

Gavin

Myers

Willems

2018

J Sports Med Phys Fitness

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BACKGROUNDː We examined the effect of early-onset of muscle damage and low muscle glycogen on cardiorespiratory and metabolic responses to low-intensity exercise.METHODSː Twelve men cycled for 10 min at 50% maximal oxygen uptake before, and 12 h after a morning downhill run (five, 8 min bouts at -12% gradient, with 2 min rests) under normal (NORM) and lowered glycogen (LOW) conditions, following a crossover design with conditions separated by six weeks. Cardiorespiratory responses were recorded, with oxidation measures derived from stoichiometry equations.RESULTSː Muscle damage symptoms post-downhill (0 h) were similar between conditions.Carbon dioxide ventilatory equivalent increased 12 h post-downhill for LOW (P<0.05), but not NORM (P=0.7). A trend towards decreased respiratory exchange ratio (RER) was shown 12 h post-downhill for LOW (1.00±0.07 to 0.89±0.12, P=0.06), but not NORM (0.94±0.11 to 0.94±0.08; P=0.6). Twelve hours after LOW downhill running fat oxidation increased (0.21±0.18 g•min -1 to 0.36±0.27 g•min -1 ; P<0.05) and carbohydrate oxidation decreased (2.68±0.52 g•min -1 to 1.98±0.75 g•min -1 ; P<0.05); NORM oxidation rates were unchanged (fat: 0.26±0.18 g•min -1 to 0.33±0.18 g•min -1 ; P=0.5; carbohydrate: 2.51±0.49 g•min -1 to 2.29±0.47 g•min -1 ; P=0.3). CONCLUSIONː Cycling at low-intensity 12 h post-downhill running with lowered muscle glycogen increased fat oxidation, decreased carbohydrate oxidation and elevated carbon dioxide ventilation. Damaging exercise with reduced glycogen availability increases fat utilization during subsequent low-intensity exercise as little as 12 h later.

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The effect of glycogen reduction on cardiorespiratory and metabolic responses during downhill running

Cited by 6 publications

References 33 publications

Acute and Delayed Neuromuscular Alterations Induced by Downhill Running in Trained Trail Runners: Beneficial Effects of High-Pressure Compression Garments

Acute and Delayed Neuromuscular Alterations Induced by Downhill Running in Trained Trail Runners: Beneficial Effects of High-Pressure Compression Garments

Effects of 120 g/h of Carbohydrates Intake during a Mountain Marathon on Exercise-Induced Muscle Damage in Elite Runners

Cardiorespiratory and metabolic responses after exercise-induced muscle damage: the influence of lowered glycogen

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