In fasted individuals exercising, fat breakdown is more strongly suppressed in obese men than in lean men due to the activity of alpha-2-adrenergic receptors.

During exercise, a biological signal that normally slows fat breakdown has less effect in people who are endurance-trained compared to those who are not, suggesting that training changes how fat tissue responds to this signal.

Eating a high-fat meal reduces the ability of certain receptors in fat tissue to slow down fat breakdown, and this happens directly in the fat tissue itself, not because of changes in stress hormones circulating in the blood.

In older men with obesity, insulin seems to be better at stopping fat from breaking down compared to men of normal weight, and this difference shows up whether or not the obese men have high insulin or blood sugar problems.

Eating a very high-fat meal before exercising reduces the normal biological brake on fat breakdown in fat tissue under the skin, leading to more fatty acids being released into the bloodstream during physical activity.

In men who are endurance-trained, blocking a specific receptor (α2-adrenergic) does not increase fat breakdown during exercise in abdominal fat, but it does increase fat breakdown in men who are not trained, suggesting that endurance training reduces the effect of this receptor in limiting fat breakdown.