Energetic Cost and Kinematics of Pushing a Stroller on Flat and Uphill Terrain.

Øyvind Sandbakk,Hans-Christer Holmberg,Thomas Steiner,Rilana Perl

doi:10.3389/fphys.2020.00574

Abstract

During early parenthood, walking and/or running while pushing a stroller is a common form of endurance exercise among both recreationally active individuals and athletes. Here, we investigate how pushing a stroller influences the energetic cost, gross efficiency (GE), and kinematic behavior of well-trained men and women while walking or running on flat and uphill incline. Eight men and nine women, all recreationally active, performed three 5-min submaximal tests of walking or running during four different testing sessions, in randomized order: with and without pushing a 24.3-kg stroller on a flat (1%; 6, 8/9, and 11/12 km/h for women/men) and uphill (10%; 5, 6.5/7.5, and 7.5/8.5 km/h for women/men) incline. Respiratory parameters, heart rate (HR), blood lactate concentration, and rating of perceived exertion (RPE) were determined and video-based kinematic analysis was performed in connection with all these tests. Except while walking on the flat incline, pushing a stroller increased the energetic cost of walking/running under all conditions (all p < 0.05). This was associated with shorter and more rapid strides on both inclines (all p < 0.05); however, GE was higher when pushing the stroller (p < 0.05). The increase in energetic cost of pushing the stroller was approximately threefold higher uphill than on the flat incline, and women were influenced more than men when running uphill at the highest speed (all p < 0.05). Here, we provide novel insights on the energetic cost and kinematic behavior of pushing a stroller while walking or running on flat and uphill inclines. The energetic cost of pushing a stroller was clearly higher than for unloaded exercise, coincided by shorter and more rapid strides, and especially pronounced on uphill terrain where also women were more influenced than men.

Highlights

During early parenthood, when both recreationally active individuals and athletes have less time for physical exercise, walking and/or running with a stroller offers an alternative for maintaining or improving fitness
While walking at the lowest speed on the 1% incline, pushing a stroller had no influence on physiological and perceptual variables; whereas when running on this same incline there was an interaction between conditions and intensity with respect to energetic cost and related cardiorespiratory parameters, heart rate (HR), lactate concentration, rating of perceived exertion (RPE), and stride length/rate, all of which differed between conditions at the highest speed (Table 3; all p < 0.05)
On the 10% incline, RPE values were lower for the men while pushing a stroller at both speeds, whereas HR and lactate concentration were lower in men at 7.5 km h−1 (Table 4; all p < 0.05)

Summary

INTRODUCTION

During early parenthood, when both recreationally active individuals and athletes have less time for physical exercise, walking and/or running with a stroller offers an alternative for maintaining or improving fitness (see Figure 1 for an illustration). Walking and running with a stroller at any given speed obviously involves more resistance than unloaded exercise On flat terrain, this extra resistance is due mainly to rolling friction; whereas on uphill terrain more power is required to counteract gravity and larger fluctuations in kinetic energy occur. We hypothesized that the energetic cost is greater, strides more rapid and GE unaltered when walking or running with a stroller in comparison to corresponding unloaded exercise We expected these effects to be more pronounced on uphill than flat terrain and for women compared to men

Ethics Statement

Study Design and Procedures

DISCUSSION

CONCLUSION

ETHICS STATEMENT