Self-paced hard work comparing men and women

Abstract

Six fit male subjects (23 years, 171 cm, 67 kg, maximal V˚O₂ = 2.25mmol kg⁻¹ min⁻¹ (50.3ml kg⁻¹min⁻¹)) and six fit female subjects (22 years, 163 cm, 57 kg, maximal V˚O₂= l.83mmol kg⁻¹ min⁻¹(41.1 mlkg⁻¹ min⁻¹)) performed self-paced hard work while walking over four different terrains carrying no external load, 10 kg and 20 kg. Time on each course for individual subjects was used to determine speed and energy expenditure; heart rate was recorded as each subject completed each course. Walking speed and energy expenditure of the males were found to be significantly greater (p< 005) than those of the females overall terrains (blacktop road, 1.6 km; dirt road, 1.8 km; light brush, 1.4 km; and heavy brush, 1.3 km) and for each load carriage condition. Relative energy expenditures of the males and females for all conditions were very similar(p>0.05) and remarkably constant at a value close to 45% V˚O₂max, These data indicate that the voluntary hard work rate is dependent upon maximal aerobic power. The best predictor of speed for self-paced hard work of males and females for 1 to 2 hours in duration appears to be based on 45% of maximal aerobic power.

Additional information

Notes on contributors

WILLIAM J. EVANS

Present address: Boston University, Sargent College of Allied Health Professions, Boston, Massachusetts 02215, U.S.A.