Be Consistent
The thing that really throws runners off track during the offseason is the decrease in exercise frequency—going from working out every day to working out just a few times per week. It's OK to take a week or two off training after a peak race for physical and mental regeneration, but after that you should return to daily exercise. This doesn't mean returning to daily, progressive, race-focused training. If you have time before the start of your next formal training cycle and you still need a break from hard training, train lightly or in non-sport-specific ways with a focus on fun. Just remember to do some sort of workout with consistency or you're likely to experience a damaging offseason weight gain.
More: 7 Common Diet Myths Uncovered
Keep Counting
It is not necessary to count calories all the time. Rather, it is sufficient to do so periodically as a way of auditing your diet and training. At times when your diet and training are consistent, one quick audit will cover you until your diet or training changes. But when either of these factors does change, it's a good idea to perform another audit to quantify and keep tabs on the change.
If you are like most runners, your training changes as you move into the offseason but it's not unlikely that your eating habits change too. Be sure to calculate your total daily calories consumed and burned early in each offseason and perhaps also periodically throughout it. This measure will help keep you from relaxing too much. Also, research has demonstrated that the very act of recording your eating heightens your awareness and steers you away from the worst excesses.
More: Is Your Diet Making You Gain?
Shift From Carbohydrate to Protein
Unlike fat and protein, which are used structurally in the body, carbohydrate is strictly an energy source, and it is the main energy source for high-intensity muscle work. Therefore the amount of carbohydrate in your diet should vary with your training workload. During peak training you may need anywhere from 7 to 10 grams of carbohydrate per kilogram of body weight daily, depending on your size and exactly how much you're training. But during the offseason you need less—as little as 4 grams of carbohydrate per kilogram of body weight.
More: Nutrition Troubleshooting
In addition to reducing your carbohydrate intake, you may wish to increase your protein intake during the offseason. Doing so will help you avoid gaining fat despite your reduced activity level. Eating a high-protein diet reduces appetite, eating, and fat storage, thereby promoting weight loss in those who maintain or increase their exercise level and limiting weight gain in those who have reduced their exercise level. Calorie for calorie, gram for gram, protein provides more satiety (e.g., appetite satisfaction) than carbohydrate or fat, so when you switch to a high-protein diet, you feel fuller and eat less.
More: When It's Good to Gain Weight
Sign up for your next race. 