Research

Energy balance

Exercise training increases physical activity level (PAL) in young adults only when energy intake is increased to maintain energy balance; otherwise, compensatory reductions in non-exercise activity negate the total energy expenditure increase.

If you start exercising to lose weight or boost activity, you must consciously increase your food intake to match the effort. If you do not eat more, your body will likely reduce your movement during the rest of the day (non-exercise activity thermogenesis), resulting in no net change in your total daily energy expenditure. This is especially true for older adults.

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Exercise training increases PAL in young adults when energy balance is maintained by increasing energy intake. ... The lack of an effect of exercise training on the physical activity can only be explained by a compensatory reduction of physical activity in the non-training time.
Klass R. Westerterp · Frontiers in Physiology · 2013

Why this rating

Based on a review of multiple doubly labeled water studies and specific controlled trials (Kempen et al., 1995; Meijer et al., 1999), providing robust observational and experimental data.

Source

Physical activity and physical activity induced energy expenditure in humans: measurement, determinants, and effects

Klass R. Westerterp · Frontiers in Physiology · 2013

DOI 10.3389/fphys.2013.00090

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DOI resolved against Crossref · corpus check 2026-06-10

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