Apparent Efficiency and Storage of Elastic Energy in Human Muscles during Exercise

Abstract

ASMUSSEN, E. and F. BONDE-PETERSEN. Apparent efficiency and storage of elastic energy in human muscles during exercise. Acta physiol. scand. 1974. 92. 537-545.3 subjects ran on the treadmill (10 km/h) against varying horizontal impeding forces. One subject was further studied during the same kind of walking and bicycling on the treadmill, and during work consisting in lowering and lifting the body by flexing and extending the legs from a standing or sitting position a t varying frequencies, with or without rebound in the deepest position. Workpower (W kcal/min) and the corresponding steady state metabolic rate (E kcal/min, Douglas bag method) were measured. Apparent efficiency ( N ) was calculated as AW/AEx 100 %. During load running N was 53.8, 37.6 and 41.2 %, respectively, in the 3 subjects. In the subject more extensively studied N was: running 53.8, walking 32.3, bicycling 25.1, knee-flexions (deep or half) with rebound 39.4 or 41.0, without rebound 26.1 or 21.9 70. These variations in N 740 were explained in accordance with the possibilities forre-using the energy, absorbed and stored in the muscles as elastic energy during a phase of negative exercise, in a subsequent phase of positive exercise. The condition of this is that the positive phase follows immediately after the negative. A calculation showed that during running 35-53 7% of the energy absorbed during the negative phase was re-used. Corresponding figures for walking and rebounding knee-extensions were 23 ?6 and 34 "lo, respectively, while in bicycling and knee-extensions without rebound all of the negative work degenerated into heat.

Differences in leg muscle activity during running and cycling in humans

“…In the present study the mean cycling D efficiency was 25%. Results from previous studies (Asmussen and Bonde-Petersen 1974;Suzuki 1979;Coyle et al 1992;Bijker et al 2001) have also shown that the D efficiency of cycling is indeed less than the efficiency of concentric exercise.…”

“…As a result, the gross efficiency during running can be much greater than the muscle efficiency (van Ingen Schenau et al 1997;Ettema 2001). Previous studies suggested that during running up inclines storage and re-use of elastic energy also takes place, which could explain the large D efficiencies obtained during running (Lloyd and Zacks 1972;Asmussen and Bonde-Petersen 1974). According to van Ingen Schenau (1984), however, during running up inclines, work produced by the muscles to overcome the external force is lost and can therefore not be stored.…”

“…The D efficiency during running is significantly greater than that during cycling (Zacks 1973;Asmussen and Bonde-Petersen 1974;Bijker et al 2001). Furthermore, the D efficiency of running is also much greater than the muscle efficiency, which is estimated to have a maximal value of 29% (Cavanagh and Kram 1985).…”

Oxygen uptake, heart rate, and work rate at ventilatory threshold for treadmill walking against a horizontal impeding force

“…On the basis of methods described in the previous studies, subjects performed horizontal load walking at 1.11 m/s (4 km/h) [2,5]. Horizontal loads were imposed using weights in a small basket that was connected to a wire, which was passed through a pulley and attached to a band around a subject's waist (Figure 1).…”

“…Lloyd and Zacks [1] estimated the mechanical efficiency (Apparent Efficiency, AE) during treadmill running on the basis of the rate of increasing energy expenditure for increment of work rate (load × velocity). Asmussen and Bonde-Petersen [2] also reported about the AE of walking and running using a similar technique according to Lloyd and Zacks [1]. Bijker et al [3] compared the delta efficiency of running with that of a bicycle ergometer exercise.…”