# Increase in Brain-Derived Neurotrophic Factor After Cycling Exercise Resisting Electrically Stimulated Antagonist Muscle Contractions in Overweight Japanese People: A Randomized, Controlled, Single-Blind, Crossover Trial

## TL;DR

A new exercise method combining cycling with electrical stimulation increases brain-derived neurotrophic factor more than regular cycling in overweight individuals.

## Contribution

The study introduces a hybrid exercise method that significantly boosts BDNF levels in overweight people compared to traditional cycling.

## Key findings

- HERG significantly increased BDNF levels more than CERG in overweight individuals.
- Both HERG and CERG increased BDNF and lactate levels after exercise.
- Lactate levels did not differ significantly between HERG and CERG.

## Abstract

Background: A hybrid training system (HTS) combining antagonist muscle electrical stimulation and voluntary muscle contraction has been developed using electrically stimulated eccentric antagonist muscle contractions. The exercise method that combines a conventional cycle ergometer with HTS (HERG) adds additional exercise intensity to the conventional cycle ergometer through electrical stimulation. Exercise-induced brain-derived neurotrophic factor (BDNF) production appears to have neuroprotective effects and contributes to improved metabolic regulation. Changes in BDNF after exercise are related to exercise intensity. Therefore, combining a cycle ergometer with electrical stimulation may be an effective approach.

Purpose: The purpose of this study was to evaluate the effect of the HERG on BDNF secretion.

Participants and methods: Fourteen healthy adults participated in the study. The participants performed two types of exercise at the anaerobic threshold: HERG and a cycling ergometer alone (CERG). A comparative study using a 2×2 crossover method was conducted to examine the differences in BDNF and lactate levels after HERG and CERG. A linear mixed model was used to compare changes in BDNF between HERG and CERG.

Results: Both HERG and CERG significantly increased BDNF and lactate levels after exercise. In overweight individuals with a BMI of 25 or higher, the change in BDNF levels after HERG was significantly greater than after CERG [ΔBDNF: 5500.96±7965.83 ng/ml, 1921.29±5308.22 ng/ml, respectively; p=0.0339]. There was no significant difference in the change in lactate levels after exercise between HERG and CERG (p=0.8632).

Conclusion: In overweight individuals, HERG increased post-exercise serum BDNF levels more than ergometer exercise alone, despite the exercise intensity remaining the same at the anaerobic threshold. The exercise method that combines the HERG may be a useful form of exercise for overweight individuals.