Related Experiment Video
Updated: Sep 14, 2025
09:04
Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy
Published on: February 20, 2018
12.6K
Time-variability of muscle oxygen saturation during graded maximal exercise
Lluc Montull1, Natàlia Balagué2, Monika Petelczyc3
1Complex Systems in Sport Research Group, National Institute of Physical Education of Catalonia (INEFC), University of Lleida, La Seu d'Urgell, Spain.
European Journal of Applied Physiology
|July 21, 2025
Summary
Muscle oxygen saturation variability changes significantly during intense exercise, indicating reduced oxygen transport efficiency as fatigue sets in. This microscopic measure offers new insights into exercise intensity and physiological networks.
Area of Science:
- Exercise Physiology
- Biomedical Engineering
- Muscle Metabolism
Background:
- Physiological and kinematic variables show exercise workload and fatigue effects.
- Microscopic variables, like muscle oxygen saturation, reflecting muscle metabolism dynamics, are underexplored for time-variability analysis.
- Assessing exercise intensity and fatigue requires sensitive microscopic measures.
Purpose of the Study:
- To compare the time-variability structure of tissular saturation index (TSI) during graded maximal exercise until exhaustion.
- To investigate the sensitivity of microscopic variables in reflecting exercise intensity and fatigue.
- To explore the potential of muscle oxygen saturation time-variability for exercise assessment.
Main Methods:
- Nineteen participants underwent a graded maximal running exercise protocol with increasing speed.
- Time-variability of TSI from the quadriceps was analyzed using Detrended Fluctuation Analysis (DFA) and Sample Entropy (SampEn).
- Analysis focused on the initial and final 2048 data points (204s each) of the exercise test.
Main Results:
- A significant decrease in the Hurst (H) exponent was observed (0.84 to 0.49, p<0.01).
- A corresponding significant increase in Sample Entropy (SampEn) was found (1.12 to 1.40, p<0.01).
- These changes indicate a shift towards uncorrelated white-noise dynamics as exhaustion approached.
Conclusions:
- Muscle oxygen saturation time-variability is a promising measure for assessing exercise intensity.
- The findings suggest reduced efficacy of oxygen transportation with increasing workloads.
- Microscopic variable analysis can complement macroscopic and mesoscopic approaches in studying physiological networks during exercise.
Related Concept Videos
01:19Special considerations while measuring oxygen saturation
697
Assessing respiratory rate concurrently with pulse measurement is fundamental to patient care, providing valuable insights into the patient's respiratory function. The normal breathing rate for an adult usually falls within a normal range of 12 to 20 breaths per minute. Abnormal respiratory rates can signal underlying health conditions or the need for immediate intervention.
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is...
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is...
697
01:17Exercise and Cardiac Output
1.3K
Regular physical activity is essential for maintaining cardiovascular health, with aerobic exercises being particularly effective. According to the American Heart Association, 150 minutes of moderate to intense aerobic exercise per week is recommended for a healthy heart. Aerobic activities may include brisk walking, running, bicycling, cross-country skiing, and swimming, ideally performed three to five times per week.
Sustained exercise increases the muscles' oxygen demand, which can be...
Sustained exercise increases the muscles' oxygen demand, which can be...
1.3K
01:20Exercise and Cardiovascular Response
1.1K
Exercise significantly impacts cardiovascular response, which is crucial for understanding patient health and designing effective treatment plans.
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...
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...
1.1K
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
1.3K
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...
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...
1.3K
01:27Exercise and Muscle Performance
1.6K
Exercise induces a range of adaptations in muscle tissue, depending on the type and duration of activity. Such physical training can be broadly categorized into two types: endurance exercises and resistance exercises.
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
1.6K
01:27Oxygen Transport in the Blood
3.3K
Hemoglobin (Hb) is a crucial molecule in the human body, consisting of four polypeptide chains, each bound to an iron-containing heme group. This unique structure enables hemoglobin to bind to oxygen, with each molecule capable of combining with four molecules of oxygen, leading to rapid and reversible oxygen loading. When fully loaded with oxygen, it is called oxyhemoglobin, while hemoglobin that has released oxygen is called reduced hemoglobin or deoxyhemoglobin. As hemoglobin binds oxygen,...
3.3K