The Post-Workout Supplement Window: What You Need & When You Need It

Post-workout nutrition is essential and will produce better strength, body composition, and endurance results, according to your training goal.

However, there’s much confusion and debate as to what you need to consume and when you need it. This tip will tell you what we know for sure based on the research, and provide additional pointers from practical experience for best results.

A review of post-workout nutrition studies published in the Journal of the International Society of Sports Nutrition makes the following points:

1) Theoretically, there is a post-workout window of opportunity in which trainees need to consume nutrients immediately after training to achieve optimal rebuilding of damaged tissue and restoration of energy reserves. A supercompensation effect means that body composition and exercise performance will be enhanced if the proper ratio of nutrients are consumed during the “window.”

The importance and existence of the “window” depends on a variety of factors including training status (trained or untrained), age, volume and intensity of training, workout mode (aerobic vs. anaerobic), and training fasted or fed, among other things. Therefore, there’s no universal answer, but there are basics that

shouldn’t be ignored.

2) Muscle glycogen is a source of energy during resistance training: Studies show that a moderate volume can reduce muscle glycogen by between 12 to 38 percent.

But there’s also evidence that high-intensity resistance training with low muscle glycogen doesn’t impair anabolic signaling or muscle protein synthesis during the post-workout recovery period. This suggests that if you’re trying to lose fat, or improve your body’s ability to burn fat for energy, training in a glycogen-depleted state may not be a bad thing.

But, if you are training twice a day, whether in endurance sports or strength training, you should definitely take carbohydrates post-workout to replenish glycogen stores.

Additionally, if you are very lean and your goal is strength and muscle development, using carbs in the post-workout window is a good idea because research shown that glycogen is replenished faster during the first two hours after training. Best results come from taking carbs with protein.

3) High-intensity training with moderate volume (6 to 9 sets per muscle group) has been shown to reduce glycogen by up to 39 percent. But, this or greater volume typically requires decreased training frequency that permits for the replenishment of glycogen without urgent post-workout carb feeding. If you train exhaustively with recovery of less than 24 hours, carbs are called for, otherwise, they aren’t required for the purpose of replenishing glycogen.

4) Muscle protein breakdown is best prevented by eating a high-quality protein meal pre-workout, and then supplementing with protein after training. The authors suggest that the classical post-exercise objective to quickly reverse catabolic processes to promote recovery and growth may only be applicable in the absence of a properly constructed pre-exercise meal. Don’t train on an empty stomach!

5) The key here is that acute muscle breakdown and protein synthesis both contribute to long-term muscle and strength gains, so you have to consider how nutrition affects the pair and look at what you get from proper nutrition over the long-term.

Taking protein right after training leads to greater muscle development in old and young subjects and in the trained and untrained. For example, a study that compared taking protein and carbs immediately after lifting or two hours after showed that elderly untrained men had greater growth in the quad muscles when supplementing immediately after training. Male body builders also benefited more from taking protein, carbs, and creatine pre- and post-workout than taking the same supplement in the morning and evening.

6) For advanced trainees and the elderly, utilizing the “window” appears most important. For advanced trainees, protein synthesis happens more in the myofibrillar component than mitochondrial, meaning immediate feeding with a high concentration of the amino acid leucine and whey protein are needed.

The elderly also benefit from a large dose of leucine and an overall large amount of protein—one study showed greater protein synthesis in the elderly from 40 grams of whey immediately after training compared to 20 grams.

Take away the following points:

Don’t train on an empty stomach. Eat protein and healthy fat and avoid fast-digesting carbs before lifting.

Always take whey protein or amino acids post-workout to support protein synthesis and muscle development.

Based on practical experience, you should consider taking branched-chain amino acids during training to prevent protein breakdown.

If your goal is fat loss, avoid carbs post-workout. Otherwise, use them wisely—if your goal is glycogen replenishment and muscle building, a conservative approach is to consume a supplement containing carb and protein in a 3:1 or 4:1 ratio within 30 minutes following exercise. This translates to 1.2 to 1.5 g/kg of simple carbs (dextrose, sucrose) with 0.3 to 0.5 g/kg of a quality protein containing essential amino acids.