pedal power for occupational activities: effect of power output and pedalling rate on physiological responses

because of the socio-economical conditions of farmers in developing countries including india, human muscle power is going to contribute energy requirements for performing many farm activities for the next two decades. pedalling is the most efficient way of utilising power from human muscles. pedal power enables a person to drive devices at the same or higher rate as that achieved by hand cranking, but with far less effort and fatigue. however, the use of pedal power for occupational work such as stationary farm operations has got scant attention in the past. keeping these points into consideration a study was planned to optimise power output and pedalling rate for stationary farm operations. physiological responses of 12 male subjects were studied on a computerised bicycle ergometer at five levels of power output (30–90 w) and seven levels of pedalling rates (30–90 rev min⁻¹). analysis of data indicated that physiological responses were significantly affected with power output as well as pedalling rate. increase in physiological responses (heart rate and oxygen consumption rate) over rest (delta values) were significantly higher when pedalling frequency was 30 rev min−1 and above 50 rev min⁻¹. there was no significant difference between physiological responses at 40 and 50 rev min⁻¹. physiological responses increased linearly with power output and were significantly different at different power outputs. the delta values of physiological responses at 60 w power output and 50 rev min⁻¹ pedalling rate (δhr = 40 beats min⁻¹ and δvo2 = 0.56 l min⁻¹) were within acceptable limits for continuous pedalling work. from the results of the study it was concluded that for daylong pedalling work the power output from an indian agricultural worker should be limited to 60 w and pedalling rate should be 50 rev min⁻¹. relevance to industry the optimal power output and pedalling rate may be used for the ergonomic design of a dynapod or any pedalling device for efficient utilization of human muscle power with reduced drudgery and fatigue.