Correspondence Between Values of Vertical Loading Rate and Oxygen Consumption During Inclined Running

Abstract

Purpose The aim of this study was to provide a theoretical model to predict the vertical loading rate (VLR) at different slopes and speeds during incline running. Methods Twenty-nine healthy subjects running at least once a week performed in a randomized order 4-min running trials on an instrumented treadmill at various speeds (8, 10, 12, and 14 km h−1) and slopes (− 20%, − 10%, − 5%, 0%, + 5%, + 10%, + 15%, + 20%). Heart rate, gas exchanges and ground reaction forces were recorded. The VLR was then calculated as the slope of the vertical force between 20 and 80% of the duration from initial foot contact to the impact peak. Results There was no difference in VLR between the four different uphill conditions at given running speeds, but it was reduced by 27% at 5% slope and by 54% at 10% slope for the same metabolic demand (similar $${\dot{\text{V}}\text{O}}_{{2}}$$ V ˙ O 2 ), when compared to level running. The average VLR measured at maximal aerobic intensity during level running would be decreased by 52.7% at + 5%, by 63.0% at + 10%, and by 73.3% at + 15% slope. Moreover, VLR was dependent on the slope in downhill conditions. Conclusion This study highlights the possibility to use uphill running to minimize rate of mechanical load (i.e., osteoarticular load) from foot impact on the ground and as a time-efficient exercise routine (i.e., same energy expenditure than in level running in less time).

Look to the stars—Is there anything that public health and rehabilitation can learn from elite sports?

“…For injured or in-rehabilitation athletes, several methods have been developed to decrease the mechanical load and enable exercise despite biomechanical constraints or pain like: running at relative lower body weight on a Low-Gravity treadmill ( 88 ), on a water immersion treadmill ( 89 ), uphill ( 90 ) or in hypoxia ( 91 ). The knowledge acquired on the physiological responses in such conditions may be useful for many clinical populations with locomotion limitation; for example for patients who are subject to excessive body weight ( 92 ) and/or elderly patients ( 93 ).…”

Increased oxygen uptake in well-trained runners during uphill high intensity running intervals: A randomized crossover testing

“…Nevertheless, besides adequate periodization and polarization models in endurance sports, reducing loading rates is still recommended as an effective means to reduce the risk of developing running injuries ( Bowser et al, 2018 ). In this context, increasing the slope might lead to a significantly lower vertical loading rate during uphill running compared to flat level running ( Gottschall and Kram, 2005 ; Lemire et al, 2022a ). Also, increasing the slope from flat level running to 7% was found to reduce flight time and increase floor contact time, in turn resulting in highly significant increases in step frequency ( Padulo et al, 2013 ).…”