Effect of training with different intensities and volumes on muscle fibre enzyme activity and cross sectional area in the m. triceps brachii

Abstract

This study primarily examined how intermittent versus continuous endurance training, using similar or dissimilar volumes, affected muscle fibre enzyme activities in the triceps brachii muscle. Thirty-two subjects performed either intermittent (60% of 1RM) or continuous (30% of 1RM) elbow extensions 3 times week(-1) in a training apparatus. Training was performed until either a low (five) or a high volume (8 weeks) was accumulated. Muscle biopsies from the m. triceps brachii were taken pre- and post training and following 8 weeks of detraining. Marker enzymes for muscle fibre oxidative (succinate dehydrogenase SDH) and glycolytic (glycerophosphate dehydrogenase; alpha-GPDH) capacity was assessed by histochemistry, and the resulting enzyme activities measured by image analysis. The type of training affected enzyme activities differently. In type 1 fibres, continuous and intermittent training was equally effective in increasing SDH activity, while intermittent training increased SDH activity more than continuous training in type 2 fibres (P < 0.05). Intermittent training increased alpha-GPDH activity more than continuous training both in type 1 (P < 0.001) and type 2 fibres (P < 0.05), but the increase in glycolytic capacity following intermittent training was larger in type 1 (54%) than in type 2 fibres (23%). There was no effect of training volume on oxidative or glycolytic capacity in either fibre type. Thus, when training intensity is sufficient to stimulate to increases in oxidative and glycolytic capacity, the SDH and alpha-GPDH response seems to be volume independent. Detraining reduced Post-T enzyme activities to baseline (all; P < 0.01).

Properties of the vastus lateralis muscle in relation to age and physiological function in master cyclists aged 55–79 years

“…These properties of the VL were also associated with training volume to which mitochondrial complex protein I was also associated. These relationships might simply be explained by the known effects of endurance training commonly observed on skeletal muscle oxidative capacity in young adults (Gjøvaag & Dahl, ; Hepple, Mackinnon, Goodman, Thomas & Plyley, ; Holloszy & Coyle, ) and the role that these have in influencing endurance cycling performance and aerobic power (Bassett & Howley, ). The findings relating to oxygen uptake kinetics are in general agreement with previous research indicating that the association between oxygen uptake kinetics and type I fibres is in part due to a greater capillarity of type I fibres which reduces the variability in blood flow to, and the transit time through, the working muscle at the onset of exercise (Piiper, ; Pringle et al., ).…”

Influence of repeated sprint training on pulmonary O2 uptake and muscle deoxygenation kinetics in humans

“…Specifically, the all-out nature of the RST would have required the recruitment of a large proportion of type II fibers, whereas ET would require the recruitment of predominantly type I fibers (29). It has been shown that interval training induces greater oxidative enzyme adaptations in type II fibers than continuous training (24,30), and that type IIb fibers manifest greater training-induced elevations in oxidative capacity as training intensity increases above V O 2peak (20). These fiber-type-specific adaptations would be expected to result in faster V O 2 kinetics and enhanced tolerance to high-intensity exercise (12,18,38,44).…”

Effects of Two Different Weight Training Programs on Swimming Performance and Muscle Enzyme Activities and Fiber Type

“…This benefit to longer-duration aerobic performances from a 30-second training regime has been suggested elsewhere (1,15,18) Other mechanisms that contribute to improvements in short-term aerobic performance have been suggested. These include time to fatigue on V _ O 2 max testing without changes in V _ O 2 max and the positive effects of enhanced neuromuscular adaptations postresistance training (17,18). These adaptations may also have occurred in this study.…”

“…The greater increase in average weight per repetition and total weight moved on the PO may have resulted from differences in the fiber type composition of the muscles performing these exercises. The fiber composition of the muscles involved in the BP, predominantly the pectoralis major and minor (57% fast twitch) and the triceps brachii (65% fast twitch) (17,19), has a significantly higher fast twitch fiber composition than the muscles used during the PO exercise (latissimus dorsi 50% fast twitch and posterior deltoid 44% fast twitch) (20). This lower fast twitch composition of the muscles recruited during the PO movement suggests that a greater proportion of the ATP demand would originate from oxidative metabolism.…”