scholarly journals Modelling the effect of curves on distance running performance

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8222 ◽  
Author(s):  
Paolo Taboga ◽  
Rodger Kram
Keyword(s):  
Energy Expenditure ◽  
Metabolic Energy ◽  
Distance Running ◽  
Distance Runners ◽  
Racing Performance ◽  
Road Racing ◽  
Curve Radius ◽  
Metabolic Energy Expenditure ◽  
World Records ◽  
Distance Running Performance

Background Although straight ahead running appears to be faster, distance running races are predominately contested on tracks or roads that involve curves. How much faster could world records be run on straight courses? Methods Here,we propose a model to explain the slower times observed for races involving curves compared to straight running. For a given running velocity, on a curve, the average axial leg force (${\overline{F}}_{a}$) of a runner is increased due to the need to exert centripetal force. The increased ${\overline{F}}_{a}$ presumably requires a greater rate of metabolic energy expenditure than straight running at the same velocity. We assumed that distance runners maintain a constant metabolic rate and thus slow down on curves accordingly. We combined published equations to estimate the change in the rate of gross metabolic energy expenditure as a function of ${\overline{F}}_{a}$, where ${\overline{F}}_{a}$ depends on curve radius and velocity, with an equation for the gross rate of oxygen uptake as a function of velocity. We compared performances between straight courses and courses with different curve radii and geometries. Results The differences between our model predictions and the actual indoor world records, are between 0.45% in 3,000 m and 1.78% in the 1,500 m for males, and 0.59% in the 5,000 m and 1.76% in the 3,000 m for females. We estimate that a 2:01:39 marathon on a 400 m track, corresponds to 2:01:32 on a straight path and to 2:02:00 on a 200 m track. Conclusion Our model predicts that compared to straight racecourses, the increased time due to curves, is notable for smaller curve radii and for faster velocities. But, for larger radii and slower speeds, the time increase is negligible and the general perception of the magnitude of the effects of curves on road racing performance is not supported by our calculations.

scholarly journals Modelling the effect of curves on distance running performance

2019 ◽  
Author(s):  
Paolo Taboga ◽  
Rodger Kram
Keyword(s):  
Energy Expenditure ◽  
Metabolic Energy ◽  
Racing Performance ◽  
Model Predictions ◽  
Road Racing ◽  
Curve Radius ◽  
Metabolic Energy Expenditure ◽  
World Records ◽  
Distance Running Performance ◽  
Gross Rate

Background On a curve, the average axial leg force (Fa) of a runner is increased due to the need to exert centripetal force. The increased Fa presumably requires a greater rate of metabolic energy expenditure than straight running at the same velocity. We propose a model that explains the velocity reduction on curves, compared to straight running, assuming that runners maintain a constant metabolic rate. Methods We combined published equations to estimate the change in the rate of gross metabolic energy expenditure as a function of Fa, where Fa depends on curve radius and velocity, with an equation for the gross rate of oxygen uptake as a function of velocity. We compared performances between straight courses and courses with different curve radii and geometries. Results The differences between our model predictions and the actual indoor world records, are between 0.45 % in 3000 m and 1.78 % in the 1500 m for males, and 0.59 % in the 5000 m and 1.76 % in the 3000 m for females. We estimate thata 2:01:39 marathon on a 400 m track, corresponds to 2:01:32 on a straight path and to 2:02:00 on a 200 m track. Conclusion Our model predicts that compared to straight racecourses, the increased time due to curves, is notable for smaller curve radii and for faster velocities. But, for larger radii and slower speeds, the time increase is negligible and the general perception of the magnitude of the effects of curves on road racing performance is not supported by our calculations.

scholarly journals Modelling the effect of curves on distance running performance

2019 ◽  
Author(s):  
Paolo Taboga ◽  
Rodger Kram
Keyword(s):  
Energy Expenditure ◽  
Metabolic Energy ◽  
Racing Performance ◽  
Model Predictions ◽  
Road Racing ◽  
Curve Radius ◽  
Metabolic Energy Expenditure ◽  
World Records ◽  
Distance Running Performance ◽  
Gross Rate

Background On a curve, the average axial leg force (Fa) of a runner is increased due to the need to exert centripetal force. The increased Fa presumably requires a greater rate of metabolic energy expenditure than straight running at the same velocity. We propose a model that explains the velocity reduction on curves, compared to straight running, assuming that runners maintain a constant metabolic rate. Methods We combined published equations to estimate the change in the rate of gross metabolic energy expenditure as a function of Fa, where Fa depends on curve radius and velocity, with an equation for the gross rate of oxygen uptake as a function of velocity. We compared performances between straight courses and courses with different curve radii and geometries. Results The differences between our model predictions and the actual indoor world records, are between 0.45 % in 3000 m and 1.78 % in the 1500 m for males, and 0.59 % in the 5000 m and 1.76 % in the 3000 m for females. We estimate thata 2:01:39 marathon on a 400 m track, corresponds to 2:01:32 on a straight path and to 2:02:00 on a 200 m track. Conclusion Our model predicts that compared to straight racecourses, the increased time due to curves, is notable for smaller curve radii and for faster velocities. But, for larger radii and slower speeds, the time increase is negligible and the general perception of the magnitude of the effects of curves on road racing performance is not supported by our calculations.

scholarly journals Calculating metabolic energy expenditure across a wide range of exercise intensities: the equation matters

2018 ◽  
Vol 43 (6) ◽  
pp. 639-642 ◽  
Author(s):  
Shalaya Kipp ◽  
William C. Byrnes ◽  
Rodger Kram
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Carbon Dioxide Production ◽  
Metabolic Energy ◽  
Distance Runners ◽  
Wide Range ◽  
Using Data ◽  
Metabolic Energy Expenditure

We compared 10 published equations for calculating energy expenditure from oxygen consumption and carbon dioxide production using data for 10 high-caliber male distance runners over a wide range of running velocities. We found up to a 5.2% difference in calculated metabolic rate between 2 widely used equations. We urge our fellow researchers abandon out-of-date equations with published acknowledgments of errors or inappropriate biochemical/physical assumptions.

Study of Rest Time of Workers Using Biomechanical Analysis

2006 ◽  
Vol 22 (02) ◽  
pp. 66-71
Author(s):  
Yasuhisa Okumoto
Keyword(s):  
Energy Expenditure ◽  
Steel Structures ◽  
Metabolic Energy ◽  
Biomechanical Analysis ◽  
Human Model ◽  
Digital Human Model ◽  
Work Cycle ◽  
Rest Time ◽  
Metabolic Energy Expenditure ◽  
Digital Human

This report focuses on welding work for the assembly of large steel structures as an example of physical jobs. Task simulations using a digital human model, including metabolic energy expenditure analysis, have been carried out using the biomechanical approach for typical welding postures. Moreover, necessary rest time to recover from fatigue has been studied, and the optimal work cycle in a day was examined. As a result, it can be concluded that the flat position for welding, the most widely applied posture, requires the greatest energy expenditure, whereas the overhead position is requires the least. Furthermore, it is concluded that the rule of taking short breaks and often is preferable from the viewpoint of recovery from fatigue, especially for work where the consumption of energy is large. Finally, an optimal work cycle is proposed.

scholarly journals The Relationship Between Gait Symmetry and Metabolic Demand in Individuals With Unilateral Transfemoral Amputation: A Preliminary Study

2019 ◽  
Vol 184 (7-8) ◽  
pp. e281-e287
Author(s):  
Caitlin E Mahon ◽  
Benjamin J Darter ◽  
Christopher L Dearth ◽  
Brad D Hendershot
Keyword(s):  
Energy Expenditure ◽  
Case Series ◽  
Step Length ◽  
Metabolic Energy ◽  
Metabolic Power ◽  
Transfemoral Amputation ◽  
Preliminary Study ◽  
Spatial Asymmetries ◽  
Metabolic Energy Expenditure ◽  
The Relationship

Abstract Introduction Temporal-spatial symmetry allows for optimal metabolic economy in unimpaired human gait. The gait of individuals with unilateral transfemoral amputation is characterized by temporal-spatial asymmetries and greater metabolic energy expenditure. The objective of this study was to determine whether temporal-spatial asymmetries account for greater metabolic energy expenditure in individuals with unilateral transfemoral amputation. Materials and Methods The relationship between temporal-spatial gait asymmetry and metabolic economy (metabolic power normalized by walking speed) was retrospectively examined in eighteen individuals with transfemoral amputation walking at a self-selected velocity overground. Pearson’s product-moment correlations were used to assess the relationship between: (1) step time symmetry and metabolic economy and (2) step length symmetry and metabolic economy. The retrospective analysis of this data was approved by the Walter Reed National Military Medical Center Institutional Review Board and all individuals provided written consent. Additional insights on this relationship are presented through a case series describing the temporal-spatial and metabolic responses of two individuals with transfemoral amputation who completed a split-belt treadmill walking test. Results For the cohort of individuals, there was no significant relationship between metabolic economy and either step time asymmetry or step length asymmetry. However, the case series showed a positive relationship between step length asymmetry and metabolic power as participants adapted to split-belt treadmill walking. Conclusion There is mixed evidence for the relationship between temporal-spatial asymmetries and metabolic energy expenditure. This preliminary study may suggest optimal metabolic energy expenditure in individuals with transfemoral amputation occurs at an individualized level of symmetry and resultant deviations incur a metabolic penalty. The results of this study support the idea that addressing only temporal-spatial gait asymmetries in individuals with transfemoral amputation through rehabilitation may not improve metabolic economy. Nevertheless, future prospective research is necessary to confirm these results and implications for clinical practice.

scholarly journals Energetic consequences of using a prosthesis with adaptive ankle motion during slope walking in persons with a transtibial amputation

2013 ◽  
Vol 38 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Benjamin J Darter ◽  
Jason M Wilken
Keyword(s):  
Mechanical Properties ◽  
Energy Expenditure ◽  
Energy Cost ◽  
Metabolic Energy ◽  
Prosthetic Design ◽  
Transtibial Amputation ◽  
Ankle Motion ◽  
Technological Advances ◽  
Walking Difficulty ◽  
Metabolic Energy Expenditure

Background:Technological advances in prosthetic design include the use of microprocessors that adapt device performance based on user motion. The Proprio ankle unit prepositions the foot to adjust for walking on slopes and increases foot clearance during swing to minimize gait deviations.Study design:Comparative analysis.Objectives:To investigate the effect of a prosthesis with adaptive ankle motion on physiological gait performance during slope walking.Methods:Six persons with a unilateral transtibial amputation completed treadmill walking tests at three slopes (−5°, 0°, and 5°). The participants were tested wearing a customary device, active Proprio (Pon), and an identical inactivated Proprio (Poff).Results:Metabolic energy expenditure, energy cost for walking, and rating of walking difficulty were not statistically different between the Pon and Poff for all tested slopes. However, for slope descent, energy expenditure and energy cost for walking improved significantly by an average of 10%–14% for both the Pon and Poff compared to the customary limb. Rating of walking difficulty also showed an improvement with slope descent for both the Pon and Poff compared to the customary device. An improvement with slope ascent was found for Pon compared to the customary limb only.Conclusions:Adaptive ankle motion provided no meaningful physiological benefit during slope walking. The Proprio was, however, less demanding than the customary device for slope descent. Differences in the mechanical properties of the prosthetic feet likely contributed to the changes.Clinical relevanceWhile the adaptive ankle motion did not affect metabolic energy expenditure or energy cost for walking, the results suggest close attention should be paid to the mechanical properties of the foot component. Assessment of gait on nonlevel surfaces is recommended to better understand the implications of different prosthetic design features.

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