METABOLISM IN HIGH INCLINE WALKING

Authors

T Hancock
DE Lankford, FACSM
L Gidley

Abstract

T. Hancock¹, D.E. Lankford¹,FACSM, L. Gidley²

¹Brigham Young University Idaho, Rexburg, ID; ²Gonzaga University, Spokane, WA

High incline walking performance is highly correlated with cardiovascular fitness. Because of this relationship, resistance training is often overlooked as a mode of preparation.PURPOSE: The purpose of this study was to determine the metabolic requirement, joint angles, and work efficiency of high incline walking; specifically, to help determine if resistance training could play a vital role in preparing for high incline hiking. METHODS: Twelve males (25.2±2.3 years, 1.82±0.08 m, 79.8±15.5 kg)walked on a treadmill at speeds of 2 and 3 mph, between 0 and 30% grade, at 5% intervals. Markers on the right leg defining the torso, thigh and shank were recorded with digital video. From these markers, knee and hip joint angles for 7 consecutive heel strikes were measured for each stage. Efficiency was calculated as mechanical work of lifting the body over metabolic work (Minetti, et al., 2002). Oxygen consumption (VO₂) was recorded and averaged for the last 2-minutes of work at each incline. Linear relations were analyzed using Pearson regressions. RESULTS: VO₂at both 2 mph (9.9±1.2ml⋅kg/min to 40.6±5.4 ml⋅kg/min, r=.99) and 3 mph (12.8±3.7 ml⋅kg/min to 49.2±13.6ml⋅kg/min,r=.93) increased linearly with incline. Hip angle decreased linearly between 0 and 30% grade at heel strike at both 2 mph (157±4.8°to 120±7.4°, r=.99) and 3 mph (155±6.3°to 112±5.5°, r=.98). Knee angle also decreased linearly with incline at both 2 mph (173±5.9°to 132±6.0°, r=.99) and 3 mph (175±5.7°to 133±5.2°,r=.99). Efficiency increased to 0.21 until 20% and remained relatively similar through 30%, which is comparable to the findings of Minetti. CONCLUSION: The metabolic requirements of high incline walking are directly related to the increased knee and hip flexion angles at heel strike. These increases in joint angles indicate that there is greater hip and knee joint extension and extension velocity as incline increases with the increased need to lift the body. Additionally, the efficiency plateau indicates that muscle activity at the highest inclines was purely concentric. Therefore, we believe that training to hike at extreme inclines by incorporating body weight and/or body weight with anticipated workload lunges would greatly improve high incline walking performance for recreational and vocational purposes.

Recommended Citation

Hancock, T; Lankford, FACSM, DE; and Gidley, L (2019) "METABOLISM IN HIGH INCLINE WALKING," International Journal of Exercise Science: Conference Proceedings: Vol. 8: Iss. 7, Article 36.
Available at: https://digitalcommons.wku.edu/ijesab/vol8/iss7/36