步頻作為走路運動強度指標的可行性

Feasibility of step rate as an indicator of exercise intensity in walking

身體活動有益健康，但須遵循執行的頻率、強度、時間及類型的處方原則才能達成，其中強度是健康促進的關鍵要素。眾多身體活動中，走路是較經濟且簡易的活動方式，並有利社會大眾規律執行，但身體活動強度是否能達到健康促進的效果，則待進一步釐清。為了確保健康促進的效果，身體活動強度應控制在中度與費力身體活動的等級，但監控強度往往需要量測的儀器或設備，不僅便利性不足，且不利於多數人使用。因此，發展簡便且易理解的強度監控方式，有其必要性。因此，本文以走路運動的每分鐘步數 (步頻) 為主軸，蒐集相關文獻，探討步頻與代謝當量 (METs) 之間的關聯性，進而提供走路時的強度指標。經文獻探討指出，以走路步頻可解釋代謝當量71%至85%的變異程度，顯示步頻可望成為有效的強度指標。21至32歲成年人中度與費力身體活動 (3與6 METs) 所對應的步頻，男性為平均99與124步/分鐘，女性平均108與134步/分鐘。然而，研究也同時反映身體型態、性別及運動情境，皆會導致步頻、代謝當量及步頻推估強度的差異，其中以身高與腿長最具影響力，可為未來應用或研究的參考。

Physical activity is beneficial for health. But it must followed by the principles of exercise prescription which are exercise frequency, intensity, time and type. And the exercise intensity is the most critical factor in health promotion. Among the variety of physical activity, walking is not only economical and simple, but also easy for the general public to execute regularly. However, the effect of exercise intensity of walking which improve health still needs further clarification. The exercise intensity must be controlled in moderate to vigorous physical activity level to ensure the health promotion effect. Nevertheless, equipments or instruments are usually required in monitoring intensity which insufficient of convenience and difficult to use for ordinary people. Hence, it seems necessary to develop a simple and easy ways to monitoring exercise intensity. The present study reviewed articles about the numbers of steps per minute (step rate) in walking. The purpose was to explore the relationship between step rate and metabolic equivalents (METs), and to provide the indicator of walking exercise intensity. Previous evidences indicated that step rate is a idea predictor of METs (R2= .71 to R2= .85). Accordingly, step rate might be an effective indicator of exercise intensity. In 21 to 32 years adults, the average step rates were corresponded to moderate and vigorous physical activity (3 and 6 METs). Males’ step rates were 99 and 124 steps/min, and females’ were 108 and 134 steps/min. However, the accuracy of prediction was also influenced by body type, genders and exercise settings. Especially height and leg length should be taken into account in future applications or researches.