The context of the following conversation is Robin had began exercising for a special marathon. Robin gained muscle.:
Robin says I've lost eight pounds of fat and put on three of muscle using a combination of long runs and weights in the run-up to the marathon..
The friend responds I hope you're not doing too much..
Robin responds About two, two-and-a-half hours each day now. The marathon is in two weeks, and I'll slow down after it's over..
The friend responds How do you feel?.
Robin responds A little tired today, so I'm resting tomorrow..
The friend responds Good. Rest is a necessary part of conditioning..