Journal article
Manipulating training intensity and volume in already well-trained rats: effect on skeletal muscle oxidative and glycolytic enzymes and buffering capacity
Applied physiology, nutrition, and metabolism, Vol.32(3), pp.434-442
06/2007
Handle:
https://hdl.handle.net/2376/109613
PMID: 17510678
Abstract
Well-trained endurance athletes undergo periods of high-intensity interval training (HIT) or high-volume training (HVT) to improve exercise performance, but little is known about the mechanistic changes that occur during this time. The purpose of this study was to examine the influence of HIT and HVT on the activities of citrate synthase (CS) and phosphofructokinase (PFK), and on intramuscular buffering capacity (β
m
) in already well-trained rats. At 4 weeks of age, Wistar rats were divided into sedentary (SED;; n = 18) and exercise training groups (n = 38). Following a 10 week preliminary training program, trained rats were divided randomly into 3 further groups that completed 4 additional weeks of continued endurance (CON, n = 14), high-intensity training (HIT, n = 12), or high-volume training (HVT, n = 12). Soleus (SOL), red and white gastrocnemius (RG and WG), and red and white vastus (RV and WV) muscles were removed 24-48 h after a final run-to-fatigue performance test (30 m·min
-1
;; 25% grade) to determine the activities of CS, PFK, and β
m
. No differences in run time to exhaustion were found between the groups. However the HIT group possessed CS and PFK activities and β
m
in WV muscle that were 60%, 24%, and 10% higher, respectively (all p < 0.05), compared with the HVT group;; differences were not found between the HIT and CON groups. Although no differences in run performance were found, HIT compared with HVT in already well-trained rats resulted in significantly higher oxidative and glycolytic capacities of fast-contracting fibres. No differences were shown in fast-contracting muscle between HIT and CON.
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Details
- Title
- Manipulating training intensity and volume in already well-trained rats: effect on skeletal muscle oxidative and glycolytic enzymes and buffering capacity
- Creators
- Paul B Laursen - School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Building 19, Room 162, 100 Joondalup Drive, Joondalup, Western Australia 6027, AustraliaSusan A Marsh - School of Human Movement Studies, The University of Queensland, Brisbane, AustraliaDavid G Jenkins - School of Human Movement Studies, The University of Queensland, Brisbane, AustraliaJeff S Coombes - School of Human Movement Studies, The University of Queensland, Brisbane, Australia
- Publication Details
- Applied physiology, nutrition, and metabolism, Vol.32(3), pp.434-442
- Academic Unit
- Pharmaceutical Sciences, Department of
- Identifiers
- 99900547014801842
- Language
- English
- Resource Type
- Journal article