Acute Metabolic Changes with Lower Leg-Positioned Wearable Resistances during Submaximal Running in Endurance-Trained Runners.

Field Field,Plews Plews,Uthoff Uthoff,Gill Gill

doi:10.3390/sports7100220

Field Field, Plews Plews + Show 2 more

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https://doi.org/10.3390/sports7100220

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Abstract

The aim of this study was to determine the acute metabolic effects of different magnitudes of wearable resistance (WR) attached to the lower leg during submaximal running. Fifteen endurance-trained runners (37.8 ± 6.4 years; 1.77 ± 0.7 m; 72.5 ± 9.8 kg; 58.9 ± 7.4 L/min VO2max; 45.7 ± 5.8 min 10 K run time) completed seven submaximal running trials with WR loads of 0, 0.5, 1, 1.5, 2, 2.5 and 3% body mass (BM). Based on regression data, for every 1% BM increase of additional load, oxygen consumption (VO2) increased by 2.56% and heart rate increased by 1.16%. Inferential based analysis identified that ≤1% BM were enough to elicit responses in VO2, with a possible small increase (effect size (ES), 90% confidence interval (CI): 0.22, 0.17 to 0.39), while 3% BM loads produced a most likely very large increase (ES, 90% CI: 0.51, 0.42 to 0.60). A training load score was extrapolated using heart rate data to determine the amount of internal stress. An additional 1% BM resulted in an extra 0.39 (0.29 to 0.47) increase in internal stress over five minutes. Lower leg WR elicited substantial increases in lactate production from the lightest loading (0.5% BM), with a likely moderate increase (ES, 90% CI: 0.49, 0.30 to 0.95). Lower-leg positioned WR provides a running-specific overload with loads ≥ 1% BM resulting in substantial changes in metabolic responses.

Highlights

From early generations as hunter gatherers, humans have evolved to run for extended periods of time, commonly referred to as endurance running [1]
The purpose of this research was to examine the acute metabolic effects of submaximal running with wearable resistance (WR) loads ranging from 0.5%–3% body mass (BM)
The statistical aim of this study was to make an inference about the impact on metabolic stress of submaximal running with WR, which requires determining the magnitude of an outcome

Summary

Introduction

From early generations as hunter gatherers, humans have evolved to run for extended periods of time, commonly referred to as endurance running [1]. Endurance running performance is determined by physiological mechanisms, such as maximum oxygen uptake (VO2max ) [2], blood lactate concentrations relative to the percentage of VO2max that a runner can sustain (%VO2max at second ventilatory threshold VT2 ) [3,4], and the metabolic cost of running at a given velocity, i.e., running economy (RE) [2]. These factors may be modified through varying strength training methods, leading to improved RE, muscular power production and running performance [5]. Adding WR to the limbs using loads ranging from 0.3–8.5% BM has shown a greater increase in metabolic demand compared to unloaded

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