The effect of environmental temperature on exercise-dependent release of brain-derived neurotrophic factor

ABSTRACT

Brain-derived neurotrophic factor (BDNF) is a biomarker of cognitive function that is released into the blood stream following exercise, and cognitive function is impaired by environmental temperatures that are hot and cold. Purpose: To evaluate the exercise-dependent release of BDNF in different environmental temperatures. Methods: Recreationally trained males each completed three trials consisting of cycling for 1 h at 60% W_max at three different temperatures: 33°C (hot), 7°C (cold), and 20°C (moderate room temperature). Blood was taken from the antecubital vein pre-exercise, immediately post-exercise, and 3 h post-exercise. Respiratory gases were collected periodically throughout exercise and recovery. Results: BDNF was elevated immediately following an exercise bout (1711 ± 766 pg·ml⁻¹) regardless of temperature from pre-exercise (1257 ± 653 pg·ml⁻¹, p = 0.001) and returned to basal levels following 3 h of recovery (1289 ± 650 pg·ml⁻¹, p = 0.786). There was no effect (p > 0.05) of temperature on BDNF following the exercise bout. Plasma glucose was elevated in hot (6.2 ± 0.9 mmol) over cold (5.3 ± 0.6 mmol, p = 0.035) and moderate room temperature (5.2 ± 0.5, p = 0.008). VO₂ was elevated during exercise in hot (3.01 ± 0.45 L·min⁻¹) over cold (2.67 ± 0.35 L·min⁻¹, p = 0.005) and moderate room temperature (2.80 ± 0.38 L·min⁻¹, p = 0.001). There was no relationship between BDNF and plasma glucose (p > 0.05) or VO₂ across any time point or temperature (p > 0.05). Conclusion: With aerobic exercise, BDNF is elevated; however, the release of BDNF is not impacted by different environmental temperatures during exercise.

KEYWORDS:

• BDNF
• cycling
• ELISA
• exercise
• glucose
• heat

Abbreviations

BDNF	=	Brain-derived neurotrophic factor
C	=	Cold
ELISA	=	Enzyme-linked immunosorbent assay
H	=	Hot
PGC-1α	=	Peroxisome proliferator-activated receptor gamma coactivator 1-alpha
RT	=	Moderate room temperature

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.

Funding

This publication was made possible by grants from the National Institute for General Medical Science (NIGMS; 5P20GM103427), a component of the National Institutes of Health (NIH) and its contents are the sole responsibility of the authors and do not necessarily represent the official views of NIGMS or NIH.