Some articles said that the CR subjects exhibited more restlessness, or "foraging" type behavior. This hypothesis wasn't tested as far as I know, though.

Based on my experience, I didn't feel less active or lethargic, just hungry. I think my body conserved its calories by reducing resting metabolic rate: Decreases in pulse, blood pressure, body temperature, body mass. My desire to exercise did not diminish, and neither did my capacity for aerobic exercises like running and swimming.