Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval, Québec, Québec, Canada.
Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Québec, Canada.
Am J Physiol Endocrinol Metab. 2024 Sep 1;327(3):E344-E356. doi: 10.1152/ajpendo.00098.2024. Epub 2024 Jul 24.
This cardiometabolic imaging study was designed to document the adaptation of middle-aged recreational cyclists to a large exercise prescription not aiming at weight loss. Eleven middle-aged recreational male cyclists traveled 1,144 km over seven consecutive days. A comprehensive cardiometabolic profile including visceral and ectopic adiposity assessed by magnetic resonance imaging was obtained at baseline and following the exercise week. Cardiorespiratory fitness (CRF) was measured using maximal cardiopulmonary exercise testing. During the week, heart rate was monitored to calculate individual energy expenditure. Baseline characteristics of cyclists were compared with 86 healthy males in the same age range. Cyclists presented higher baseline CRF (+9.2 mL/kg/min, < 0.0001) and lower subcutaneous (-56.2 mL, < 0.05) and liver (-3.3%, < 0.05) fat compared with the reference group. Despite the large energy expenditure during the cycling week, the increase in energy intake limited decreases in body weight (-0.8 ± 0.9 kg, < 0.05) and body mass index (-0.3 ± 0.3 kg/m, < 0.05). Loss of fat mass (-1.5 ± 1.0 kg, < 0.001) and a trend toward an increased lean mass (+0.8 ± 1.2 kg, < 0.07) were observed. Visceral adiposity (-14.1 ± 14.2 mL, < 0.01) and waist circumference (-3.2 ± 1.7 cm, < 0.0001) decreased, whereas subcutaneous (-2.7 ± 5.1 mL, NS), liver (-0.5 ± 0.9%, NS), and cardiac (-0.3 ± 2.3 mL, NS) fat remained unchanged. This cardiometabolic imaging study documents middle-aged recreational cyclists' subcutaneous and visceral adiposity as well as cardiac and liver fat responses to a large volume of endurance exercise despite an increase in energy intake aimed at limiting weight loss. Even when being accompanied by a substantial increase in energy intake to compensate energy expenditure and limit weight loss, a large volume of endurance exercise performed within a short period of time is associated with a significant reduction in visceral adiposity. High cardiorespiratory fitness is associated with low levels of liver fat in middle-aged males.
这项心脏代谢影像学研究旨在记录中年休闲自行车运动员适应大运动量锻炼方案的情况，而该方案并非旨在减肥。11 名中年休闲男性自行车运动员在连续 7 天内骑行 1144 公里。在基线和运动周后，通过磁共振成像获得全面的心脏代谢特征，包括内脏和异位脂肪堆积。使用最大心肺运动测试测量心肺功能适应性（CRF）。在一周内，监测心率以计算个体能量消耗。将自行车运动员的基线特征与同年龄范围的 86 名健康男性进行比较。与对照组相比，自行车运动员的基线 CRF 更高（+9.2 mL/kg/min，<0.0001），皮下脂肪（-56.2 mL，<0.05）和肝脏脂肪（-3.3%，<0.05）更低。尽管在骑车周内消耗了大量的能量，但能量摄入的增加限制了体重（-0.8±0.9 kg，<0.05）和体重指数（-0.3±0.3 kg/m，<0.05）的下降。观察到脂肪量减少（-1.5±1.0 kg，<0.001）和肌肉量增加的趋势（+0.8±1.2 kg，<0.07）。内脏脂肪堆积减少（-14.1±14.2 mL，<0.01），腰围减小（-3.2±1.7 cm，<0.0001），而皮下脂肪（-2.7±5.1 mL，NS），肝脏脂肪（-0.5±0.9%，NS）和心脏脂肪（-0.3±2.3 mL，NS）保持不变。这项心脏代谢影像学研究记录了中年休闲自行车运动员的皮下和内脏脂肪堆积以及心脏和肝脏脂肪对大量耐力运动的反应，尽管增加了能量摄入旨在限制体重减轻。即使伴随着大量的能量摄入来补偿能量消耗并限制体重减轻，在短时间内进行大量的耐力运动也与内脏脂肪堆积的显著减少有关。在中年男性中，较高的心肺功能适应性与较低的肝脏脂肪水平相关。
