Left ventricular responses to a program of lower-limb strength training.
Nine healthy male subjects ages 18-27 exercised five days per week. Three days per week they performed five repetitions of squats, leg extensions and leg flexions with maximal resistance for a total of 11 sets. On the other two days each week subjects performed five leg presses and 20 calf raises with maximal resistance. Resting echocardiograms and physiologic evaluations were made prior to starting the strength training and again after ten weeks of training. Resting heart rate +/- SEM before and after training was 65 +/- 2 and 58 +/- 1.7 beats/min (P < .001). Maximal O2 uptake did not change significantly. Left ventricular wall thickness +/- SEM before and after training increased from 0.76 +/- .02 to 0.85 +/- 0.04 cm (P < .05). Left ventricular mass +/- SEM increased from 81.9 +/- 5 to 92.3 +/- 3.7 g (P < .05). The percentage of left ventricular fractional shortening +/- SEM increased from 32 percent +/- 1.2 to 36 percent +/- .9 (P < .001). Lower limb strength training in normal subjects did not increase maximal O2 uptake, but did induce increases in left ventricular wall thickness similar to that seen in champion strength-trained athletes. In addition, improvement in left ventricular performance without significant changes in left ventricular volumes was also observed.
D000293:Adolescent; D000328:Adult; D006332:Cardiomegaly / Q000209:etiology; D006321:Heart / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D007866:Leg; D008297:Male; D010806:Physical Education and Training; D010807:Physical Endurance; D016276:Ventricular Function