Afternoon Fatigue Related to Diet?

By May 23, 2012

I have been weight strengthening every other day as part of my weight loss program. This is not a mega workout program, but something I have been able to do in my home with consistency; I am now lifting 5 pounds! On the days that I lift weights I notice a lot of fatigue between 2 and 3 in the afternoon. I have tried a protein snack, hoping that this would help, but it doesn’t seem to make a difference. What would you recommend? Helen Frost, R.N., B.A.N.

Dear Helen:

First, congratulations on finding a balanced, consistent exercise program that is working for you. Strength training is a wonderful way to build lean muscle mass and improve your metabolism. It sounds like you have set reasonable, realistic goals and are doing very well.

Now let’s address the issue of your afternoon fatigue. Without having more information and doing a full assessment, I’m going to make some educated guesses regarding possible causes. It’s common to assume that we should eat whenever we feel fatigued, but many times we aren’t even hungry, so it’s not food that our bodies need. For example, are you dragging because you aren’t drinking enough fluids, especially water? Or are you simply tired because you are getting up earlier on the days you work out? Rule out other possible culprits, before making dietary changes.

It is a popular misconception that people need to automatically increase their protein intake when they are lifting weights. In fact, most Americans are getting more than enough protein to begin with. So unless you are a strict vegetarian or are severely restricting calories, you are probably consuming plenty of protein to build new muscle tissue as you strength train, and it’s doubtful that you need that high protein snack.

More likely, you should take a look at your carbohydrate intake on your exercise days. Carbs are needed to fuel our muscles on a day-to-day basis, and we have limited storage capacity (in the form of glycogen). You could try adding a small extra serving of a carbohydrate source to your lunch on workout days, such as a piece of fruit, a slice of whole grain bread or a glass of skim/low fat milk. A slight change in the composition of your lunch might be enough to ward off that afternoon fatigue. Again, you don’t mention if you are hungry when you have your snack, and if you aren’t, then that’s a clue that a higher percentage of carbohydrates at lunch might do the trick. If, however, you are indeed hungry in the afternoon, then I would recommend a light snack that includes both carbohydrate and protein (cereal with milk, fruit and cheese, yogurt, whole grain crackers with peanut butter, etc.).

Try experimenting a bit with these suggestions, and you’ll find the solution that works best for you. Keep up the good work!