Related Experiment Video
Updated: May 23, 2026

Skeletal Muscle Gender Dimorphism from Proteomics
Published on: December 14, 2011
Variations of serum testosterone concentrations after physical exercises of different duration
Abstract:
Serum testosterone concentration was determined before and after physical activities of different duration. The subjects under study were: (1) 7 competitive walkers before and after a 20-km race (average race time 1 h 30 min); (2) 9 middle-distance runners before and after 1-h training; (3) 16 marathon runners before and after a marathon run (average running time 2 h 33 min); (4) 30 ultramarathon runners before and after a 107-km race (average running time 14 h). Serum testosterone increased by 51.8% (NS) in competitive walkers, by 38.2% (P less than 0.05) in middle-distance runners, and by 44.9% (P less than 0.01) in marathon runners; it decreased by 31.9% (P less than 0.001) in the ultramarathon runners. These findings, and similar variations of serum testosterone observed in an ultramarathon runner during a 6-h training session, suggest that serum testosterone increases during physical activities lasting up to 3 h and decreases to or even below the pre-exercise values for longer physical efforts. The possible mechanisms responsible for these differences are discussed.
More Related Videos
07:26Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans
Published on: October 17, 2018
07:40Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training
Published on: October 10, 2019
Related Concept Videos
Exercise and Muscle Performance
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...
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...
Testosterone: Functions and Regulation
Signs of Puberty
Exercise Stress Test
Exercise stress testing, commonly known as a treadmill test, is a noninvasive procedure used to evaluate cardiovascular function and diagnose heart conditions.
Definition
An exercise stress test measures the heart's response to exertion using a treadmill or stationary bicycle. Chest electrodes record the heart's electrical activity through an ECG, and blood pressure is monitored regularly.
Purposes
Serum Studies: Renal Function Tests