Related Experiment Video
Updated: Jun 25, 2026

Non-invasive Assessments of Subjective and Objective Recovery Characteristics Following an Exhaustive Jump Protocol
Published on: June 8, 2017
Influence of postexercise cooling techniques on heart rate variability in men
Anthony S Leicht1, Wade H Sinclair, Mark J Patterson
1Institute of Sport and Exercise Science, James Cook University, Townsville, Queensland, Australia. anthony.leicht@jcu.edu.au
Intravenous cold saline infusion for hyperthermia treatment significantly alters heart rate control, reducing heart rate complexity and long-term regulation compared to ice packs or fan cooling.
Area of Science:
- Exercise Physiology
- Autonomic Neuroscience
- Cardiovascular Regulation
Background:
- Core body temperature reduction is critical for hyperthermia treatment.
- The impact of cooling methods on autonomic heart rate control remains poorly understood.
Purpose of the Study:
- To investigate how three field-based hyperthermia treatments affect neural control of heart rate (HR) using heart rate variability (HRV).
Main Methods:
- Nine healthy men with exercise-induced hyperthermia underwent randomized recovery treatments: intravenous cold saline (IV), ice packs (ICE), or fan cooling with water spray (FAN).
- HR dynamics were analyzed using power spectral, Poincare plot, approximate entropy, and fractal scaling analyses every 10 minutes for 40 minutes.
Main Results:
- All treatments reduced core body temperature and heart rate.
- Intravenous infusion (IV) resulted in higher heart rate and reduced spectral/geometrical HRV, complexity, and long-term HR control compared to ICE and FAN.
- IV treatment indicated reduced vagal and/or increased sympathetic modulation.
Conclusions:
- Field-based hyperthermia treatments differentially affect autonomic control of heart rate.
- Intravenous cold saline infusion may alter sympathovagal balance more than ice packs or fan cooling.
- Further research is needed to examine these altered sympathovagal balances.
More Related Videos
05:48Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology
Published on: September 21, 2018
08:12Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions
Published on: June 5, 2019
Related Concept Videos
Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
Responses to Heat and Cold Stress
Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be met...