Why Can't I Exercise Before My DEXA Scan?
- 1 day ago
- 2 min read
To obtain the most accurate and consistent results, we ask clients to avoid exercise on the day of their DEXA scan.
The purpose of pre-scan preparation is to standardise testing conditions so results can be reliably compared over time. While factors such as food and fluid intake can be controlled relatively easily (1kg of food/fluid = 1kg of additional lean mass), exercise introduces a source of variability that is difficult to standardise and impossible to accurately quantify.
Exercise can temporarily influence measurements of lean mass, fat mass and visceral adipose tissue (VAT) by altering fluid distribution throughout the body. The magnitude and direction of these changes vary depending on factors such as the type of exercise performed, its duration and intensity, the muscles involved, hydration status, recovery status, and environmental conditions such as temperature and humidity.
Unlike eating or drinking, where the effect on body weight is relatively predictable, the impact of exercise on DEXA measurements is inconsistent. Even when the same activity is repeated, physiological responses may differ due to factors such as recovery, training load, sweat losses, and weather conditions. As a result, it is not possible to determine how much of a change in a DEXA result reflects a true change in body composition versus the temporary effects of recent exercise.
For this reason, we recommend avoiding exercise on the day of your scan. By minimising unnecessary sources of variability, we can improve the reliability of your results and ensure that changes observed between scans are more likely to reflect genuine changes in body composition rather than differences in testing conditions.
Normal daily activities, such as walking from your car to the clinic, will not affect your results. The recommendation relates to exercise and training sessions performed before your scan.
