Abstract

An experiment of three parts was designed to compare: prone knee flexion (KF) and seated knee extension (KE) cost:work ratios (c:w); 60 and 80 percent one-repetition maximum (1 RM) KF and KE c:w; and one-leg KF c:w with the hip extended and with the hip flexed. After determining resting oxygen uptake (VO2) for five minutes, VO2 and vertical work were measured during KE or KF. Recovery VO2 was measured until resting VO2 was reached. Energy cost was estimated by multiplying five times net O2 (L), and total work was determined by summing the vertical work done on limbs and weights. In the first part, seven subjects were tested four times, at 60 and 80 percent of 1 RM for both KE and KF. A sets x repetitions scheme of 4 x 10 was used in the 60 percent 1 RM tests, and 4 x 5 was used in the 80 percent 1 RM tests. In part two (five minutes of continuous work), 10 subjects were tested twice, at 25 percent of 1 RM KE and KF. In part three (five minutes of continuous work), five subjects were tested twice, at 25 percent of 1 RM KF with hip extended and hip flexed. The results of this study indicate that KF and KE economy is probably affected by exercise intensity, and that hip position affects KF economy. Verf.-Referat (gekuerzt)