I've been reading your blogs about steady state vs. interval training and they have been…
Pre- vs. Post-Workout Nutrition – Q&A
Question: If protein and other nutrients take time to be broken down and utilized, does it really matter whether or not you have a PWO meal, if you’ve had a large meal relatively soon before your training? In other words, can a Pre-workout meal be just as beneficial as a post-workout meal (if not better)? Isn’t it important to have AA in your blood stream when training? And if there is a designated time for digestion, wouldn’t the other nutrients effectively help recovery, even though they were consumed before hand?
Answer: As usual this is going to be one of those longish ‘it depends’ kinds of answers and I’m probably going to go way off track in trying to answer it. As I discussed in The Protein Book, some recent research certainly suggested that pre-workout nutrients (carbs and protein, and I’ll assume the combination from here on out) were superior to post-workout nutrients in terms of promoting protein synthesis.
Other research wasn’t so positive but it did look like having nutrients in the system during/immediately after workout might be better than waiting until afterwards. Some of it depended on the form of nutrients (especially protein consumed); in one study immediate pre-workout essential amino acids (EAA’s) were better than post-workout EAA’s. In another, a whole protein taken right before training wasn’t superior to post-workout; this may have been an issue of digestion time.
I would note that protein synthesis isn’t the only goal here; maintaining high levels of training intensity during a workout is also key and pre- and/or during-workout nutrition can benefit folks there as well. A complication of that research was that most of it was done fasted, that is first thing in the morning, after folks hadn’t eaten for many hours. While that is relevant to some people (e.g. those who train first thing in the morning), many if not most trainees will have eaten something prior to the immediate pre-workout period. This complicates issues.
And the general picture that seems to be developing is that if someone is in the ‘fed’ state, that is they have eaten within a few hours of their workout, pre-workout nutrients don’t seem to provide any major benefit. This mainly has to do with the slow digestion time of whole foods. A relatively ‘normal’ whole-food meal is still releasing nutrients (carbs and protein) into the bloodstream as much as 4-5 hours after you eat it.
So if you’ve eaten within 2-3 hours of your workout, you already have nutrients in the system and probably don’t have much of a need to eat anything right beforehand. On the other hand, if it’s been 4 or more hours since your last meal (e.g. you eat lunch at 1pm and don’t get to the gym until 5-6pm), consuming something immediately before your workout is probably a good idea. Not only will you get some protein into the system that will be available during and right after training, a small amount of carbs will ensure that blood glucose is normalized so that you can have your best workout.
Depending on what type of training you’re doing, you may also find that during and post-workout nutrition is also beneficial. The length of the workout, type of workout, etc. all go into this determination.
So again, the answer is that it depends. Certainly there is some logic to having nutrients in the system during and right after training by consuming something right before workout. But this is complicated by whether or not you’ve eaten a whole-food meal in the few hours before your training. As above, if you’ve eaten within 2-3 hours, I wouldn’t bother with anything before your workout.
If it’s been 3-4 hours since your last meal, I’d suggest at least experimenting with eating something maybe 30 minutes before workout (this could be a protein bar, a small carb/protein drink) to normalize blood glucose and get some amino acids into the system is probably a good idea.
About 0.3-0.5 g/kg (0.14-0.23 g/lb) of both carbs and protein would be a good starting place. For a 180 lb lifter that’s 25-40 grams of carbs and protein combined about 30 minutes before your workout (to give the nutrients time to get into your system).
I would mention that a small percentage of people seem to get rebound blood sugar issues from consuming rapidly digesting nutrients right before a workout; if you’re one of them you’ll want to wait until you start warming up to eat anything. Exercise blunts insulin response and waiting until your warm-up to start eating anything limits the possibility of a negative blood glucose response.
I should also mention that one or two recent studies have intriguingly suggested that training in a completely fasted state might have benefits in terms of activation of some of the molecular markers involved in growth and adaptation to training. So far nobody has looked to see if this truly impacts on growth down the road so I’m remaining on the fence until more research becomes available. My gut hunch says that having nutrients in the system will be superior to not having them available but if research comes out against that, I’ll happily change my mind.
Hope that answers your question.