Bodybuilders worship the post workout meal. In fact, the meal is an institution all by itself and it’s a part of every lifter’s diet. Hordes of bodybuilders swear by this magical timeframe as the foundation of a proper weightlifting regimen.
The post workout meal – meticulously consumed within 30 minutes after your workout – even has a special name, it’s the “anabolic window of opportunity.”
Sound grandiose, right? Bestowed with such a title, you’d think that this particular meal trumps all other meals.
And you’d be right. After all, a properly timed post workout meal purportedly diminishes soreness and fatigue, replenishes glycogen levels, and ramps up protein synthesis while post workout breakdown.
With so many benefits, it’d be foolish not to have a meal right after your workout.
It’s easy to get carried away as we chase our ideal bodies, and with that pursuit comes the urge to squeeze out any possible advantage – nutritional timing included.
But is it really any more beneficial to have a meal immediately after your workout, as opposed to some time later?
An immediately post workout followed meal is supposed to have three main benefits; protein breakdown prevention, glycogen repletion, and muscle protein synthesis.
Glycogen repletion immediately after exercise is an established part of the post workout meal benefit trifecta.
As blood glucose levels fill up, it’s converted into glycogen and stored in the liver and muscles. Once your body has sufficient energy levels in the form of glucose it stores it for future use as glycogen.
Consequently, glycogen fuels your workouts. So it’s imperative to keep your muscle replete with the empowering substance.
In fact, as one recent study1 suggests, just 3 sets of 12 reps performed to failure resulted in a “26.1% reduction of glycogen stores … while 6 sets at the same intensity led to a 38% decrease.”
Hence, emphasizing glycogen levels as crucial to working out is a valid and justified position. Especially when considering that glycogen availability has been shown2 to also mediate post workout muscle protein breakdown.
However, even though it’s clear that glycogen confers benefits during the workout, it doesn’t mean that we must replenish it immediately after one.
In fact, only frequent – less than 24 hours apart – workout sessions of the same muscle warrant immediate post workout glycogen re-synthesis. to mitigate the “double dip” effect.
To emphasize the point, the Victoria University of Technology conducted a study3 which “compared the immediate post-exercise ingestion of 5 high-glycemic carbohydrate meals with a 2-hour wait before beginning the recovery feedings,” and found “no significant between-group differences were seen in glycogen levels at 8 hours and 24 hours post-exercise.”
Weight Lifting Versus Endurance
There’s another important distinction, glycogen repletion is important for a narrow subset of endurance sports. This is especially true when there are less than 8 hours between the glycogen depleting events.
Hence, glycogen repletion is substantially more crucial after endurance type exercise. One possible reasonis the type of exercise and training that endurance athletes experience.
Specifically, endurance sports – unlike resistance training – require high volume and high frequency training bouts.
Consequently, these exercises drain glycogen reserves more than the typical high volume but low frequency weight lifting workout, and require immediate repletion.
Protein Breakdown Prevention
The ‘anabolic window of opportunity’ has another supposed benefit; it spikes insulin, thereby preventing muscle protein breakdown.
Here’s a little background; a University of Nottingham study4 found that “a rise in muscle protein breakdown occurs immediately after a workout.” Naturally then, insulin’s intrinsic anti-catabolic5 6 7 properties are supposed to counteract the breakdown.
On the surface, the logic checks out. Your body breaks down muscle after a workout, so you combat the effect by having a meal that spikes your insulin, an anti-catabolic hormone.
It turns out, however, that a pre workout meal renders the insulin spike superfluous!
Therefore, obtaining the desired insulinogenic effect is easy with mixed meals which include amino acids.
Hence, the post workout insulin boost is redundant because a good pre workout meal elevates your insulin levels long enough to aid your workout and the period right after.
The Pre Workout Cure
Researchers examined the boost by conducting a study10 to determine metabolic effects during a 5 hour period after ingesting “a solid meal comprised of 75 grams of carbohydrates, 37 grams of protein, and 17 grams of fat.”
As a result, the meal raised “insulin 3 levels about baseline within 30 minutes of consumption. At the 1 hour mark, insulin was 5 times greater than fasting, and at the 5 hour mark, insulin was still double the fasting levels.”
To put the findings into context, a pre workout meal not only boosts insulin levels, but it at least doubles them for longer than five hours. Consequently, your insulin levels are well elevated during and after workout.
Another study11 determined that a pre workout consisting of protein alone – a 45 g dose of whey protein isolate – kept insulin elevated for 2 hours.
Consequently, it’s clear that the including carbohydrates in your pre workout meal keeps insulin levels elevated post workout.
Muscle Protein Synthesis
Last but not least, meticulous nutritional timing purportedly enhances.
Unfortunately, the evidence that a post workout meal positively affects muscle protein synthesis, is even less conclusive.
As we read over all the available research, a singular pattern emerged; there’s no pattern.
The fitness community often criticizes studies for their contradictory results, when it comes muscle protein synthesis, it may be right.
To Carb or not to Carb
The incongruent results show up in many aspects. It’s not only the nutritional timing but also the nutritional content that science can’t reach a consensus on.
There’s perennial debate over mixing carbs with protein. Some bodybuilders even swear by a post workout stick of pixie dust for maximum recovery and carbohydrate delivery.
Unfortunately, the research on post workout carbohydrates isn’t conclusive, so you might have to load up on pixie powder.
For example, a study12 found that “the combined effect on net muscle protein synthesis of carbohydrate and amino acids are given together after resistance exercise is roughly equivalent to the sum of the independent effects of either given alone.”
While these studies 13 14 concluded that “co-ingestion of carbohydrate during recovery does not further stimulate post exercise muscle protein synthesis when ample protein is ingested,” and that “insulin is not additive or synergistic to rates of MPS or MPB when CHO is co-ingested with a dose of protein that maximally stimulates rates of MPS” respectively.
It’s worth mentioning that the aforementioned contradictory studies pertain to muscle protein to synthesis rates after a workout and don’t invalidate the research results from the muscle protein breakdown data referenced above.
Good Old Protein
Nutritional Timing and Muscle Protein Synthesis
So we can’t agree on what dietary combination maximizes post workout muscle protein synthesis, but is the timing just as debated?
On one hand, a Vanderbilt University study19 found that “early postexercise ingestion of a nutrient supplement enhances accretion of whole body and leg protein, suggesting a common mechanism of exercise-induced insulin action.”
In fact, the authors found that a meal right after your workout increases muscle protein synthesis by three times, “when compared to just 12% after delayed consumption.”
Conversely, a University of Texas at Galveston study20 found that “ essential amino acids with carbohydrates stimulate muscle protein anabolism by increasing muscle protein synthesis when ingested 1 or 3 h after resistance exercise.”
Hence, the University of Texas study didn’t replicate Vanderbilt study’s “drop off” effect.
So Where Does That Leave Us?
The data is inconsistent. As mentioned earlier, there are multiple studies that contradict each other. However, there is some consensus.
Specifically, a pre workout meal will carry over into the post workout recovery period.
A University of Texas at Galveston study21 solidified the pre workout effect. The authors concluded that taking 20 grams of whey protein right before exercise kept amino acid levels elevated to “4.4 times pre-exercise resting levels … and did not return to baseline until 3 hours post exercise.”
A 2017 article22 from the University of California at Northridge reinforced the findings, citing in part, “our findings refute the contention of a narrow post-exercise anabolic window to maximize the muscular response and instead lends support to the theory that the interval for protein intake may be as wide as several hours or perhaps more after a training bout depending on when the pre-workout meal was consumed.”
Hence, a well composed and timed pre workout meal effectively eliminates any need for post workout protein or amino acids.
Most research glosses over one important detail when considering post workout meals; whether you’re exercising in a fasted or fed state.
The majority of science referenced above places an emphasis on the pre workout meal. Consuming ample nutrients before exercise is enough to carry you through and after.
However, there is some evidence that fasted exercise increases the rate of muscle protein breakdown. Consequently, thefitness regimen can cause negative post workout amino acid balance levels.
Hence, besides endurance training, fasted state weight lifting also warrants a meal right after your workout.
In this instance, the nutrients will counteract any further amino acid depletion carried over from your fast.
Taking in all the findings here’s the best recommendation, take ample protein before and after exercise.
How much protein is a whole other topic of debate. But the safe bet is around .5 g/kg of LBM (lean body mass) pre and post exercise.
Inconsistent data makes carbohydrate recommendations more difficult. However, the most prudent recommendation is hitting your daily goal, and worrying about specific timing or frequency.
Even if the research is inconsistent, it doesn’t mean you can’t experiment yourself. Try different nutritional and timing combinations and see what works for you.