Effect of exercise intervention on thigh muscle volume and anatomical cross‐sectional areas—Quantitative assessment using MRI

Abstract

The objective of this study was to evaluate the location-specific magnitudes of an exercise intervention on thigh muscle volume and anatomical cross-sectional area, using MRI. Forty one untrained women participated in strength, endurance, or autogenic training for 12 weeks. Axial MR images of the thigh were acquired before and after the intervention, using a T1-weighted turbo-spin-echo sequence (10 mm sections, 0.78 mm in-plane resolution). The extensor, flexor, adductor, and sartorius muscles were segmented between the femoral neck and the rectus femoris tendon. Muscle volumes were determined, and anatomical cross-sectional areas were derived from 3D reconstructions at 10% (proximal-to-distal) intervals. With strength training, the volume of the extensors (13.1%), flexors (13.5%), and adductors (13.9%) increased significantly (P < 0.05) between baseline and follow-up, and with endurance training, the volume of the extensor (13.7%) and sartorius (15.1%) increased significantly (P < 0.05). No relevant or statistically significant change was observed with autogenic training. The greatest standardized response means were observed for the anatomical cross-sectional area in the proximal aspect (10-30%) of the thigh and generally exceeded those for muscle volumes. The study shows that MRI can be used to monitor location-specific effects of exercise intervention on muscle cross-sectional areas, with the proximal aspect of the thigh muscles being most responsive. Magn Reson Med 64:1713-1720,

Skeletal Muscle Hypertrophy After Aerobic Exercise Training

“…Therefore, from investigations implementing 12 weeks of either resistance or aerobic exercise training, both modes of exercise have elicited a similar increase in quadriceps muscle volume suggesting that both modes of exercise are equally effective at stimulating hypertrophy in the muscles utilized over 12 weeks. These findings are supported by Hudelmaier et al (20) and remain consistent with exercise programs of 6 months duration (29, 33). Collectively, studies observing skeletal muscle growth after aerobic exercise training observe an average increase of over 7% (Table 1), which is comparable to the hypertrophy after resistance exercise training (25, 29, 37).…”

Quadriceps and Hamstrings Morphology Is Related to Walking Mechanics and Knee Cartilage MRI Relaxation Times in Young Adults

“…However, a number of studies have demonstrated that single-slice ACSA is predictive of muscle volume and that muscle ACSA measurements are predictive of muscle strength and joint moments, and are sensitive to changes due to disuse/training. 7,8,11,16,27 In our study, the ACSA for the vastus medialis might have been underestimated, which could have influenced our findings related to the QuadML ACSA ratio but is unlikely to have influenced those related to the QH ACSA ratio, because mid-thigh ACSA is considered adequate for overall quadriceps and hamstrings volume. 11 We also did not take into consideration fascicle length and pennation angle, which are used to calculate physiological CSA.…”

Pharmacological Interventions in Frailty and Sarcopenia: Report by the International Conference on Frailty and Sarcopenia Research Task Force

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