# Effects of 12 Weeks of Resistance Training on Body Composition, Muscle Hypertrophy and Function, Blood Lipid Level, and Hemorheological Properties in Middle-Aged Obese Women

## TL;DR

A 12-week resistance training program improved muscle function, reduced fat, and enhanced blood properties in middle-aged obese women.

## Contribution

A structured resistance training program was shown to improve muscle and blood properties in middle-aged obese women.

## Key findings

- Resistance training significantly improved muscle function, including peak torque and total work.
- The program decreased fat mass and improved erythrocyte aggregation and deformability.
- Participants showed significant improvements in hemorheological properties and body composition.

## Abstract

This study investigated the effects of 12-week resistance
training on body composition, blood pressure, blood lipid levels, muscle
cross-sectional area (CSA), isokinetic muscle function, and hemorheological
properties in middle-aged obese women.

Twenty-eight obese women
with a mean age of 50.79 ± 5.80 years were randomly assigned to the control
(CON, n = 13) or experimental (EXP, n = 15) group. The EXP group underwent a
resistance training program composed of warm-up, main resistance exercise
(deadlift, barbell squat, seated leg extension, and lying leg curl, bench press,
preacher bench biceps curl, barbell rowing, and dumbbell shoulder press), and
cool-down. The resistance exercise consisted of three sets of 8–10 repetitions
(reps) performed with 70–80% of 1-rep maximum, and reps and sets were increased
every 3 weeks. The training frequency was 80 min, 3 days per week for 12 weeks.
The CON group maintained their daily lifestyle without training. All participants
underwent measurements of body composition (weight, body mass index, lean body
mass, fat mass, and % body fat), blood pressure (systolic blood pressure,
diastolic blood pressure, mean arterial pressure, and pulse pressure), blood
lipid levels (triglycerides, total cholesterol, high-density lipoprotein
cholesterol, and low-density lipoprotein cholesterol), CSA of the muscles
(quadriceps, hamstring, and total thigh muscle), isokinetic muscle function (peak
torque [PT], relative PT, mean power, and total work [TW]), and hemorheological
properties (erythrocyte deformability and aggregation) before and after 12 weeks
of training.

The EXP group showed a significant improved muscle
function, including PT (p < 0.001), relative PT (p < 0.001)
in extension 60°/s, TW (p < 0.001) in extension
180°/s, and TW (p = 0.018) in flexion 180°/s.
Regarding hemorheological properties, the EXP group showed significant
improvement in erythrocyte aggregation (p < 0.001) and deformability
(p < 0.001).

The present study verified that our
resistance training program resulted in greater muscle function, decreased fat
mass, and improved hemorheological properties.

This study was registered with cris.nih.go.kr (No. KCT0007412).