Donovan C M, Brooks G A
J Appl Physiol Respir Environ Exerc Physiol. 1977 Sep;43(3):431-9. doi: 10.1152/jappl.1977.43.3.431.
A comparison of walking against vertical (gradient) and horizontal (trailing weight) forces was made during steady-rate exercise at 0.250, 500, and 750 kg-m/min with speeds of 3,0, 4.5, and 6.0 km/h. In all cases exponential relationships between energy expenditure (calculated from the steady-rate respiration) and increasing work rate and speed were observed which indicated that muscular efficiency during walking is inversely related to speed and work rate. "Work" (level, unloaded walking as the baseline correction), "delta" (measured work rate as the baseline correction), and "instantaneous" (derived from the equation describing the caloric cost of work) efficiencies were computed. All definitions yielded decreasing efficiencies with increasing work rates. At work rates above 250 kg-m/min the curves describing the relationship between energy expenditure and work rate were parallel for vertical and horizontal forces, indicating equivalent efficiencies in this range. Only the delta and instantaneous definitions accurately described these relationships for vertical and horizontal work. Determinations of combined work loads (gradient plus trailing weight) were made and the energy costs of both types of work found to be additive.
在以0.250、500和750千克-米/分钟的稳定速率进行运动时，比较了对抗垂直（梯度）力和水平（拖重）力行走的情况，速度分别为3.0、4.5和6.0千米/小时。在所有情况下，均观察到能量消耗（根据稳定速率呼吸计算得出）与工作速率和速度增加之间呈指数关系，这表明行走过程中的肌肉效率与速度和工作速率呈反比。计算了“工作”（以水平、无负载行走作为基线校正）、“增量”（测量的工作速率作为基线校正）和“瞬时”（从描述工作热量成本的方程推导得出）效率。所有定义均显示随着工作速率的增加效率降低。在工作速率高于250千克-米/分钟时，描述能量消耗与工作速率之间关系的曲线对于垂直力和水平力是平行的，表明在此范围内效率相当。只有增量和瞬时定义准确描述了垂直和水平工作的这些关系。对组合工作负荷（梯度加拖重）进行了测定，发现两种工作类型的能量成本是可加的。
