Welcome back to the third and final installment of my series looking at the myth of the post-resistance training anabolic window. Before we get started I’d like to give you a brief recap of what we’ve already learned. In part 1 we discussed some of the common beliefs behind post-workout nutrition. We talked about the misconception of how fast protein needs to get into your system post-workout, how casein and whey had very similar effects on muscle-protein synthesis and we talked about how whey protein concentrate gives you the best bang for your buck for whey proteins. In part 2 we looked at how soon you get nutrients into your system post-workout and how it didn’t make a difference in muscle-protein synthesis, we looked at differences between pre-workout and post-workout nutrition, and we looked at how there is plenty of conflicting research on the topic of the anabolic window and learned that protein synthesis can be raised from 24-48 hours post-workout. This week we will dig deeper into the topic of pre-workout vs post-workout nutrition, whole food vs supplements post-workout, how important it is to replenish glycogen stores after a workout and I will give you my conclusion to everything researched the last three weeks.
Okay now that we’re all caught up, let’s get started! Getting right back into pre-workout vs post-workout nutrition, do you remember the study by Tipton et al. 2001 (4) from last week? That was the study that showed consumption of an essential amino acid-carbohydrate supplement had a greater affect on muscle- protein synthesis when taken pre-workout than it did post-workout. Well the same group from the above study wasn’t satisfied with those results, they also wanted to see if whole proteins would make a difference when taken either pre or post-workout. So once again we look at work by Tipton et al. (15) This time they gave subjects a mixture of whey proteins before or after resistance training. This time amino acid uptake was not significantly different between pre and post either from the beginning of exercise or from the ingestion of the drink. So while doesn’t show that pre-workout nutrition is more important than post as did the previous study, it does show that one wasn’t any better than the other at increasing muscle-protein synthesis. If there is an anabolic window like we are told, wouldn’t the post-workout intake have a better response than the pre-workout group since the pre-workout group hadn’t just exercised?
The next question when it comes to post-workout nutrition is if there is a difference between taking in supplements or real food. One wouldn’t think so given how we already established casein and whey proteins have similar responses in muscle-protein synthesis, but I like to be as thorough as possible. Surprising as it was I had a very difficult time finding research comparing muscle-protein synthesis post-workout when either food or whey protein was taken. What I was able to find, however, was some research comparing consuming milk post-workout to a soy protein drink and a sports drink, all taken 1 hour after resistance training. In the study they either drank 2 cups of skim milk or they matched the macronutrient ratios in the soy group and all three groups consumed the same amount of calories. 56 novice healthy young men trained 5 days per week for 12 weeks. They tracked strength and muscle fiber size and body composition. The results showed there was no difference in strength in any of the three groups. There were increases in muscle fiber size, however, in the milk group which actually had the greatest increase of all 3 groups. (16) Good old fashioned milk, it really does do the body good.
One thing we haven’t covered in much detail yet which is something we hear a lot about in regards to the importance of post-workout nutrition and that is replenishing gylcogen stores. While we certainly need to replace glycogen stores the need to do so immediately after training has been shown to be false. Research has shown that while replenishing glycogen stores is important it does not need to be done within 2 hours post-workout like has been commonly noted unless the individual will be performing exercise again within 8 hours. Otherwise as long as total caloric needs are met during the next 24 hours after exercise, timing of replacing glycogen stores is not relevant. (17) Also while we are on the topic of myth busting, adding fat to meals after exercise has not been shown to alter glucose tolerance either. (18)
Putting everything we’ve learned in the last three weeks together here are my thoughts on the potential of the post-work “anabolic window.” No matter how good a meal can be for anabolism, any one meal regardless of when it’s taken is nothing in comparison to what would happen if your nutrition is totally optimized throughout the day consistently. There isn’t much evidence that the anabolic window truly exists in terms of having a greater capacity for increased muscle-protein synthesis over any other time of day. If there was a time when it would make the most sense that immediate post-workout nutrition would be more critical is if you were going into a workout either fasted or without having eaten for several hours, which would not be recommended for anyone trying to build muscle anyway. Under normal circumstances, however, there is no need to rush and get nutrients into your body as soon as possible and it doesn’t have to be the fastest absorbing supplement nor does it have to be any supplement at all. Eating a meal at your normal regular intervals should do the trick to keep protein synthesis high, especially if you are taking in nutrients before you exercise. You should replenish glycogen stores after your workout but unless you have another workout coming later that day, it doesn’t matter how soon you do it.
Too often people have poor nutrition and/or training plans who have a huge focus on post-workout nutrition like it will come to the rescue and make up for everything else. Especially considering that this “anabolic window” probably doesn’t even exist at all. I’ve said it before and I’ll continue to say it again and again: train hard, get your nutrition in check (all of the time) and get your rest. Do those three things and everything else is minor. Don’t think you can slack on those and make up for it because of some magical window after a workout. You need to fuel your body properly all the time for the best possible results.
In regards to pre or post-workout nutrition being more important, after doing this research I’d have to say I consider pre-workout nutrition to be the more important of the two. Given all we’ve learned about how little hormonal responses from training mean and now how little the lack of a real post-workout anabolic window is, I think the most important thing surrounding training is doing whatever it takes to get a great workout in. This is most likely to happen by properly fueling your body before your workout so you can push as hard and long as possible during training. All of that said it could still be a good idea to surround your training with proper nutrition. It certainly won’t hurt anything. 20-40 grams of quality protein pre and post-workout should be sufficient to covers your bases. (19) Going over this amount would have little if any harm, but undershooting could be less than optimal.
If you have longer strength training sessions that can last 90-120 minutes like I often do and you time your pre and post-workout meals an hour to an hour and a half before and after exercise you can keep your timing in line with maximizing muscle-protein synthesis from nutrient timing and cover pre and post-workout nutrition, whether it’s important or not. Pre-workout is where I really like to utilize whey protein because it’s an easy way to get your protein and BCAA’s in and it’s easy on the stomach so you don’t have to worry about eating anything heavy and trying to train with it digesting. Add to that whichever carb source you like (I like a banana and/or a whole wheat bagel) and you should be primed for a good workout and be set for maximizing protein synthesis. Post-workout nutrition and timing is also up to you. I personally just like to eat a meal around an hour after my workout but I definitely won’t worry if it goes longer, nor should you.