CAN RESISTANCE TRAINING IMPROVE MORE THAN MUSCULAR STRENGTH?

By: ATH Athletic Performance Director Frank Bourgeois, PhD

Summary

• Data suggests resistance exercise training (RET) improves several cardiometabolic risk factors such as systolic and diabolic blood pressure, total cholesterol and fasted glucose.

• Improvements in these risk factors are more pronounced in individuals with elevated cardiometabolic risk factors when compared to their younger and healthier counterparts.

• With minimal reports of adverse events (e.g. soft and hard tissue injury), RET can be considered a safe method of improving physical health.

Introduction

Cardiovascular and metabolic disease are internationally recognized as severe, yet largely preventable, human and economic burdens. As such, the efficacy of non-pharmacological interventions has been widely investigated in both healthy and clinical populations. To date, the most extensively studied training intervention within these populations has been moderate to vigorous aerobic exercise – with positive outcomes well documented. However, despite its popularity, resistance exercise training (RET), and its influence on cardiometabolic health has received far less attention. Therefore, the purpose of this study was to examine the impact RET has on cardiometabolic health in healthy and clinical populaces. 

What is resistance exercise training (RET)? 

RET can be defined as regularly scheduled exercise that systematically involves pushing and pulling against some form of resistance - e.g. free weight, pneumatic and accommodating resistances. Examples of RET are barbell bench press, Keiser air squat and long rubber band Romanian deadlift.

Findings 

RET regardless of duration is a safe and viable intervention for improving the cardiometabolic system across classified populations (healthy and clinical populaces). Short-, medium- and long-term RET are all effective options for generating improvements in key biomarkers, such as resting blood pressure, flow-mediated dilation, VO₂ max and metabolic indicators for healthy young and healthy older adults, and older adults with an elevated cardiometabolic risk

Approach to the Problem

A systematic literature review and a meta-analysis were conducted on 173 short- (≤6 weeks), medium- (7 to 23 weeks) and long-term (≥24 weeks) resistance training studies from 1978 to 2018 to examine data collected from 6,169 participants classified as healthy young adults (18-40 yr), healthy older adults (≥41 yr) and older adults with an elevated cardiometabolic risk (≥41 yr). Cardiometabolic markers assessed were resting heart rate, systolic and diastolic blood pressure, mean arterial pressure, flow-mediated dilation, VO₂ max, total cholesterol, triglycerides, high- and low-density lipoprotein, fasted insulin and glucose, homeostatic model assessment of insulin resistance and C reactive protein.

Discussion

Biomarker-specific comparison divulged significant improvement in systolic and diastolic blood pressure following medium- and long-term RET. Mean arterial pressure and resting heart rate showed non-significant improvement following short- and medium-term RET. VO₂ max was significantly improved following all durations of RET. Flow-mediated dilation was significantly improved following medium-term RET, and showed non-significant improvement following short- and long-term RET. Homeostatic model assessment of insulin, and fasting insulin showed significant improvement following medium-term, but not short-term RET, while fasting glucose showed significant improvement following medium-term, but not short-term RET. Lastly, non-significant improvement was shown for total cholesterol, low- and high-density lipoprotein, triglycerides and C reactive protein across all training durations.

Though all groups displayed an improvement, overall group-specific comparisons revealed healthy older adults experienced the greatest benefit from RET. Following medium-term RET, significant improvement in systolic and diastolic pressure, mean arterial pressure, resting heart rate, total cholesterol, high-density lipoprotein, fasted insulin and glucose, and C reactive protein was observed. Following long-term RET, significant improvement was seen in diastolic pressure, VO₂ max, total cholesterol and fasted glucose.

Concerning older adults with elevated cardiometabolic risk, the greatest improvements in low-density lipoprotein followed medium-term RET, while the greatest improvement in VO₂ max, and systolic and diastolic pressure was experienced following short- and medium-term RET. Lastly, considering all resistance training modalities examined (i.e. those encompassing free-weights, bodyweight, machine, circuit, elastic band and isometric exercises) only 12% of studies (≈21 out of 173 studies) reported adverse events resulting from training.

Reference

• Ashton RE, Tew GA, Aning JJ et al. Effects of short-term, medium-term and long-term resistance exercise training on cardiometabolic health outcomes in adults: systematic review with meta-analysis. British Journal of Sports Medicine. 2020;54:341-48. Doi:10.1136/bjsports-2017-098970