Experimental study on the relationship between human motion and metabolism at different exercise intensity

Abstract

The objective of the study is to observe and derive the relationship of human motion and human metabolism rate when performing exercises of different intensity. Human motion will be compared to values of VO2, blood lactate and heart rate measured, for these values are reflective of human metabolism. The Lactate Threshold of an individual can then be determined, based on the changes in human motion, once a relationship is obtained. Thirteen female athletes (mean age 21.9 ± 1.2 years, mean fat composition 25.5 ± 3.7 %, average height 161.0 ± 7.0 cm, mean weight 51.7 ± 6.4 kg, mean Bone Mineral Content (BMC) 2.3 ± 0.3 kg and lean mass 36.1 ± 4.3 kg) participated in this study. All participants completed two sets of experiments on the treadmill continuously: VO2 Sub-Max (multi-staged discontinuous run starting at speed 6 kmh¯¹ and 1% grade, interspersed with a 4 minute recovery. The treadmill running speed increases by 1 kmh¯¹ every 4 minutes) and VO2 Max (multi-staged continuous run starting at speed 10 kmh¯¹ and 1 % grade. The test is progressive, with an increment of 1 kmh¯¹ until stage 6. After which there will be an increment in grade by 2% per minute, with the speed at a constant of 15 kmh¯¹). Human motion will be captured, while VO2, blood lactate, heart rate and Rated Perceived Exertion (RPE) are consistently measured throughout the experiments. The human motion analysed demonstrated a relationship (correlation r>0.700) to human metabolism in endurance sports. The human motion (spinal flexion), the angle between the thoracic and lumbar presented a high correlation with human metabolism (r = 0.808). The equation (A) VO2lt = (VO2max - 10.29) ± 27.34 ml/kg/min can be used to predict the VO2 at LT given the VO2 at exhaustion stage.