The question becomes:
How far out from a workout should you be consuming your pre-workout meal?It all depends. What type of pre-workout meal you're eating is the most important factor.
We all know fast absorbing protein and slow digesting carbohydrates should make up the majority of our pre-workout meals. They contribute to things like increased protein synthesis, strength gains and long term energy.
Carbohydrates and Pre-Workout Meal TimingPre-workout meal timing will depend on the degree of carbs and protein in your food choices. For example, a protein shake containing 100% whey protein can be downed about 30 minutes prior to a workout and still prove to be effective. This is because the amino acids are immediately available to the body.
Slabs of grilled chicken breast should be consumed about 60 minutes out from a workout. This is due to its moderate absorption rate. Although whey protein does absorb faster than whole foods such as chicken breast, making it an ideal pre-workout weapon, there is no evidence proving that it is more efficiently digested than its "real" food counterpart. So that's definitely something to keep in mind.
It's also important to remember that foods rich in fat will down slow protein absorption and blunt blood flow to your muscles. This is quite counterproductive when you are looking to build new muscle. Shy away from foods such as peanut butter and avocados during pre-workout planning, unless you're consuming them a lot further out than 60 minutes from the actual activity.
Comparing Watermelon and OatmealAs far as carbohydrates are concerned, eating a bowl of oatmeal or brown rice as a pre-workout meal should be eaten further out from a workout. A slice of watermelon can be eaten closer to lifting.
This is primarily because the sugar content of each changes the time it should be eaten prior to lifting. Oatmeal (not the same for instant oatmeal) is relatively low on the glycemic index (55). It's also a whole grain which means it will keep your blood sugar stable and supply you with a considerable amount of energy over an extended period of time. This makes it the perfect carbohydrate source for a long workout.
On the other hand, a slice of watermelon contains a formidable amount of sugar. This scores it pretty high on the glycemic index (72). It will spike your insulin because it is absorbed rather quickly. This makes watermelon a more suitable choice for a shorter workout.
Final ThoughtsSo in conclusion, if you're thinking about eating a meal of grilled chicken breast with a bowl of brown rice prior to your training, it's safe to say 60 minutes or so before the activity is ideal.
If you're in a hurry and don't have that much time to spare, then a whey protein shake and a slice or two of watermelon 30 minutes beforehand is perfect for that minimal window of opportunity.
Now the exact volume of protein and carbohydrates you should eat will certainly vary. This variance will be based on which bodypart you are working. Your lower body and back for instance, require more of a caloric intake pre-workout. This consistent energy will help you work some of the larger muscle groups of the body.
Also, as previous stated, how long a workout will take impacts the carbs and protein you should intake prior to working out. You wouldn't consume the same amount of macros for a 20 minute workout as you would a workout that lasted one hour.
This information is simply a generalization to help you better understand and build an optimal pre-workout approach. I hope this piece helped you in some way, shape or form. Now go kick your workout's ass!
- Fruhbeck, Gema. Slow and fast dietary proteins. Nature, 391: 843-844.
- P. Galassetti et al. Effect of a high-fat meal on the growth hormone response to exercise in children. Journal of Pediatric Endocrinology and Metabolism, 19(6):777-86, 2006.