Oxygen consumption, heat production, and muscular efficiency during uphill and downhill walking

• Published in: Applied ergonomics 2002-09, Vol.33 (5), p.485-491
• Main Authors: Johnson, Arthur T., Benhur Benjamin, M., Silverman, Nischom
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Biological and medical sciences; Biomechanical Phenomena; Energetics; Ergonomics; Female; Fundamental and applied biological sciences. Psychology; Heat; Humans; Male; Muscle, Skeletal - physiology; Muscular system; Negative work; Oxygen; Oxygen Consumption; Physical Exertion - physiology; Thermogenesis - physiology; United States; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Walking; Walking - physiology
• ISSN: 0003-6870; 1872-9126
• DOI: 10.1016/S0003-6870(02)00031-5

Oxygen consumption, heat production, and muscular efficiency for walking are parameters important to know for ergonomics models and equipment design. Most of these assume that the oxygen consumption and heat production of downhill walking are the same as for uphill walking. Eight subjects wearing insulating clothing walked on a treadmill at three uphill and three downhill grades, and at level grade at a rate of 1.1 m/s. Oxygen consumption V ̇ O 2 was calculated from steady state measurements of respiratory minute volume and oxygen percentage. Heat production ( q ̇ ) was calculated from the rate of heat storage in the body and clothing. Least-squares best fit equations for oxygen consumption and heat production found were to be V ̇ O 2 =0.813+0.0361G+0.000810G 2−0.0000302G 3 and q ̇ =6.55+0.185G+0.0114G 2−0.000190G 3 where G is percent grade. Approximations show that V ̇ O 2 (downhill)=0.5 V ̇ O 2 (uphill), q ̇ (downhill)=0.67 q ̇ (uphill), and muscular efficiency η (downhill)=−2 η (uphill).