title: Effects of aerobic training, resistance training, or combined resistance-aerobic training on the left ventricular myocardium in a rat model.
abstract: This study follows the left ventricular (LV) hypertrophy in rats undergoing aerobic training alone (A), resistance training alone (R), or combined resistance and aerobic training (RA) (usually referred as concurrent training) program. A sedentary control group (C) was included. LV remodeling was evaluated using electron and light microscopy. The LV weight to body weight (LVW: BW) increased 11.4% in A group, 35% in the R group, and 18% in the RA group compared to the C group. The LV thickness increased 6% in the A group, 17% in the R group, and 10% in the RA group. The LV internal diameter increased 19% in the A group, 3% in the R group, and 8% in the RA group compared with the C group. The cross-sectional area of cardiomyocyte increased by 1% with the A group, 27% with R group, and 12% with RA training. The capillary density increased by 5.4% with A training, 11.0% with R training, and 7.7% with RA training compared with the C group. The volume fraction of interstitial collagen increased by 0.4% with training A, increased by 2.8% with R training, and 0.9% with RA training. In conclusion, except for the LV internal diameter, which increased more in the A group, the cardiac parameters increased more in the R group than in the other groups and in RA group than in A group. Collagen density increased from 5.4 ± 0.8% in the C group to 5.8 ± 0.6% in the A group (n. s.) (P > 0.05), to 8.2 ± 0.7% in the R group (P < 0.05), and to 6.3 ± 0.4% in the RA group (P < 0.05). These results demonstrate a significant increase for collagen content in the LV with R and RA exercise, but the increase was higher with R training alone than with RA training.
authors: Department of Anatomy, Uninove University, São Paulo, Brazil.
authors: Mônica Rodrigues
authors: MR
authors: De Souza
authors: Leo
authors: L
authors: Pimenta
authors: Tania Cristina
authors: TC
authors: Pithon-Curi
authors: Marco
authors: M
authors: Bucci
authors: Renata Gabriel
authors: RG
authors: Fontinele
authors: Romeu Rodrigues
authors: RR
authors: De Souza
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D006352:Heart Ventricles / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D009206:Myocardium / Q000737:chemistry* / Q000378:metabolism; D009929:Organ Size; D051381:Rats; D017208:Rats, Wistar; D055070:Resistance Training; D020257:Ventricular Remodeling
chemical_list: D003094:Collagen
keywords: Rattus norvegicus; concurrent training; endurance training; heart; strength training