Development of ergometer attachment for power and maximum anaerobic power measurement in swimming

The ergometer can be a versatile means of measurement if attachments are developed for special purposes or if attachment is developed for multi-uses. In this study, an ergometer attachment for the measurement of power was designed and the measurement of power and the maximum anaerobic power in swimming was tested. A rotation drum was attached to one pedal of an ergometer. The rotation of this drum was synchronized with the rotation of the pedal. One end of a wire for a traction by a swimmer was connected to the drum. The other end of the wire was attached to a belt around the waist of a swimmer. The swimmer swam at full strength, thus causing the drum to rotate. The rotational velocity of the drum was detected as voltage by a magnetic permanent motor and transformed to wire tractional velocity; this velocity was equal to swimming velocity. The wire tension (= load) was controlled by a load adjusting lever of the ergometer. This wire tension was equal to the load which was added to the swimmer. The power calculation was based on a curved regression equation approximated from the load and the velocity. This equation was shown as follows; (P + a) (v + b) = (P0 + a)b or its development (P + a)v = b(P0 - P) and provided that P: force or load, v: swimming velocity, P0: maximum tractional force, a and b: constants. This ergometer attachment made it possible to measure and evaluate the power and the maximum anaerobic power in swimming with ease and at low cost. Measurement and evaluation are easily performed using the system, which is just one example of the possible applications of the ergometer.