1. Set a weight-gain limit
You will probably gain less body fat during the off-season if you replace your vague intention to stay trim with a definite goal—specifically, a maximum weight limit. Use the “8 percent rule” to calculate your limit. Every runner has an optimal racing weight, and most runners have a good idea what that weight is. The 8 percent rule dictates that you should avoid gaining more than 8 percent of your ideal racing weight during the off-season.
For example, suppose your racing weight is 133 pounds. Eight percent of 133 is about 10 pounds. So in this case you’ll want set a goal not to exceed 143 pounds. Once your weight limit is established, weigh yourself once a week to track any movement toward it and make changes as necessary (e.g., lay off the eggnog) if you find yourself getting too close, too quickly.
Note that if you are already above your optimal racing weight at the start of the off-season, you still must limit your weight gain to 8 percent above your optimal racing weight, not your current weight. Not sure what your optimal racing weight is? Refer to my book, Racing Weight: How to Get Lean for Peak Performance, for help in determining it.