By Dr. Mercola
Your post-workout meal can influence the overall health effects of exercise, so what to eat after your workout is an important consideration. For example, research1 has shown that minimizing carbohydrates after exercise can enhance your insulin sensitivity, compared to simply reducing your calorie intake, and optimizing your insulin sensitivity is key for maintaining good health.
That said, it’s important to realize that optimizing your health is not the same as optimizing your performance. These two goals actually have conflicting end points, and require different strategies. In other words, you cannot optimize your athletic performance and longevity simultaneously — you need to decide which of these goals you’re trying to accomplish.
If your goal is general health and longevity, then the post-workout recommendations for strength training and cardio or high-intensity interval training (HIIT) are identical, and involve eating plenty of protein and avoiding starchy carbs. I’ll review this in greater detail below.
Competitive athletes engaged in explosive types of exercise, however, whose focus is on maximizing physical performance, need plenty of starchy carbohydrates (although not refined sugar) in their post-workout meal.
So, as you read on, keep in mind that the recommendations discussed below are primarily directed at those focused on enhancing their health and longevity, not athletic, explosive performance.
TIME-RESTRICTED EATING HELPS ACTIVATE AUTOPHAGY
To begin with the basics, ideally, you’ll want to fast for as long as you can before your morning workout. I recommend a time-restricted eating schedule where you’re fasting 14 to 18 hours each day, which means you eat all of your meals for the day within six to eight hours.
Exercising in a fasted state, whether you’re doing strength training or cardio/HIIT, will maximize autophagy — a self-cleaning process in which your body digests damaged cells, which in turn encourages the proliferation of new, healthy cells. The harder your workout, the more autophagy you will activate.
Then, shortly after you finish your workout, have your largest meal of the day with plenty of high-quality protein and nonstarchy vegetable carbs, making sure you get several grams of leucine and arginine, both of which are potent mTOR stimulators.
AUTOPHAGY AND MTOR NEED TO BE CYCLICALLY ACTIVATED
Optimizing autophagy is a key strategy for general health and longevity. However, it’s important to realize that you don’t want to keep autophagy activated all the time.
It’s important to avoid the mistake I made, which is to fear mTOR activation. Like yin and yang, mTOR activation is the necessary counterpart to autophagy. It’s needed to increase muscle mass and build fat for your cell membranes and nucleotides for your DNA. It also activates massively vital molecules such as:
- PGC-1 alpha that increases mitochondrial biogenesis
- HIF-1 alpha that increases your microcirculation
- NADPH that recharges your antioxidants
- FOXO-3 that activates the production of antioxidants when needed
For more details, David Sabatini wrote an excellent review paper two weeks ago2 “mTOR at the Nexus of Nutrition, Growth, Ageing and Disease,” published in my favorite science journal, Nature Reviews Molecular Cell Biology. As explained in this paper:
“Over the past two and a half decades, mapping of the mTOR signaling landscape has revealed that mTOR controls biomass accumulation and metabolism by modulating key cellular processes, including protein synthesis and autophagy.
Given the pathway’s central role in maintaining cellular and physiological homeostasis, dysregulation of mTOR signaling has been implicated in metabolic disorders, neurodegeneration, cancer and ageing.”
So, to summarize, fasting activates autophagy, allowing your body to clean out damaged subcellular parts. Exercising while fasted maximizes autophagy even further. In fact, exercising while you are fasting for more than 14 to 18 hours likely activates as much autophagy as if you were fasting for two to three days. It does this by increasing AMPK, increasing NAD+ and inhibiting mTOR.
Refeeding with protein after your fasted workout then activates mTOR, thus shutting down autophagy and starting the rebuilding process. These two processes need to be cyclically activated to optimize your health and avoid problems.
BENEFITS OF FASTED EXERCISE
While longevity is one significant benefit of fasted exercise, there are also more immediate benefits. For example:
|Research3 published in 2015 found women who skipped breakfast and worked out on an empty stomach had better working memory in midafternoon and reported less mental fatigue and tension later in the day than those who ate breakfast (in this case a cereal-based meal) before exercising. Other research has also shown fasted exercise can help boost your cognitive function.4|
|Fasted exercise has been shown to be particularly helpful for fat loss, as it essentially forces your body to shed fat. The reason for this is because your body’s fat burning processes are controlled by your sympathetic nervous system (SNS), and your SNS is activated by exercise and lack of food.
The combination of fasting and exercising maximizes the impact of cellular factors and catalysts (cyclic AMP and AMP kinases) that force the breakdown of fat and glycogen for energy.
A 2012 study5 confirmed that aerobic training in a fasted state lowered both total body weight and body fat percentage, while exercising in a fed state decreased body weight only.
Research6,7 published in the August 2019 issue of The Journal of Nutrition also found that fasted exercise helps curb food intake for the remainder of the day, resulting in an overall energy deficit — in this case averaging 400 calories per day, which can also contribute to weight loss.
|Exercise and fasting together also yields acute oxidative stress which, paradoxically, benefits your muscle. As explained in a 2015 study,8 reactive oxygen species (ROS) produced during exercise actually increase your body’s expression of antioxidants that help neutralize the free radicals created. According to this paper, “ROS also seem to be involved in the exercise-induced adaptation of the muscle phenotype.”|
|Fasted exercise also helps keep your brain, neuromotors and muscle fibers biologically young by triggering brain-derived neurotropic factor (BDNF) and myogenic regulatory factors (MRFs). BDNF controls neurogenesis, signaling your brain stem cells to convert into new neurons,9 while MRFs are instrumental in muscle development and regeneration.10|
|Research11 published in the October 2019 issue of The Journal of Clinical Endocrinology & Metabolism found that the timing of your meal when exercising impacts “acute metabolic responses to exercise.” Specifically, fasted exercise improved glucose and insulin sensitivity, resulting in lower insulin levels after eating.
Autophagy also facilitates muscle growth, and since your muscles are the largest sink for glucose in your body, having more muscle mass means you’ll have less glucose circulating in your blood (as it’s being stored in your muscle), and this too helps lower your insulin resistance.
|Strength training while fasted is also a simple and effective way to optimize stem cell renewal. As mentioned, tissue regeneration occurs during the refeeding phase. That’s when your body starts rebuilding and replacing all those damaged cells that were cleared out during the fasting (autophagy) phase.
Fasted strength training can further optimize tissue regeneration because, during fasting, your growth hormone level rises,12,13 and growth hormone activates genes involved in the healing of damaged tissue.14
In a sense, fasting can in some ways be likened to getting a growth hormone injection and a stem cell transplant, and by incorporating strength training at the right time, just before refeeding, you optimize all these regenerative benefits.
|The combined effect of time-restricted eating and short but intense exercise has also been sown to boost your testosterone level15,16 and help prevent depression.17,18|
IDEAL POST-EXERCISE NUTRIENTS
Generally speaking, after exercise your body is nitrogen-poor and your muscles have been broken down. Providing your body with the correct nutrients after your workout is therefore crucial to stop the catabolic process in your muscles and shift the recycling process toward repair and growth. Amino acids from high-quality animal proteins are essential for this process. Healthy sources include:
- Whey protein (minimally processed and derived from organic, grass fed, nonhormonally treated cows)
- Organic free-range eggs
- Grass fed bison, lamb or beef
As mentioned, you’ll want to make sure you’re getting several grams of leucine and arginine (mTOR stimulators) in this meal. The richest source of leucine (which helps regulate the turnover of protein in your muscle), by far, is whey protein. In fact, it can be difficult to obtain sufficient amounts of leucine from other sources.
The typical requirement for leucine to maintain body protein is 1 to 3 grams daily. However, to optimize its anabolic pathway, research shows19 you need somewhere between 8 and 16 grams of leucine per day, in divided doses.20,21
To reach the 8-gram minimum, you’d have to eat nearly 15 eggs.22 Whey, on the other hand, contains about 10% leucine (10 grams of leucine per 100 grams of protein).23 So, 80 grams of whey protein will give you 8 grams of leucine.
Arginine is a precursor to nitric oxide that also activates mTOR24 and enhances protein synthesis and muscle development. It is found in pumpkin seeds, turkey, chicken, beef and eggs. Vegetable carbs (not grains and sugars) are also an important part of your recovery meal. Beneficial sources of nonstarchy carbs include:
- Virtually any vegetable (limiting carrots and beets, which are high in sugar)
- Dark green, leafy vegetables
- Low fructose fruits like lemon, limes, passion fruit, apricots, plums, cantaloupe and raspberries. Avoid high fructose fruits like apples, watermelons and pears.
TIME YOUR POST-EXERCISE MEAL PROPERLY
Keep in mind that when you eat is just as important as what you eat. If you fail to feed your muscles at the right time after exercise, the catabolic process can go too far, potentially damaging your muscles.
After a cardio or HIIT session, wait 45 to 60 minutes and then consume a high-quality protein and vegetable-type carbohydrate. An example would be a spinach salad and some chicken, along with a serving of whey protein.
After a resistance workout, the ideal time to consume your post-workout meal is 15 to 30 minutes after finishing your session, in order to help repair your damaged muscles.
COLLAGEN BOOSTS NADPH AND QUELLS OXIDATIVE DAMAGE
Another really valuable recovery food is collagen. It helps repair soft tissue injuries, tendons, ligaments, cartilage, and fascia.
While a muscle injury is fairly easy to fix and recover from, connective tissues require very specific raw materials, namely animal-based collagen such as gelatin and bone broth. This collagen material is amino acids that get incorporated into your body to become this matrix of connective tissue.
Collagen is high in glycine, proline, and hydroxyproline while being relatively low in branched-chain amino acids. For this reason, collagen will not significantly stimulate mTOR, so you can take it at high amounts without risking overdosing on protein. Sisson recommends taking about 40 grams a day if you have a soft tissue injury, and this will not count toward your protein intake.
Collagen also helps quell oxidative damage by inhibiting NOX superoxide production and boosting NADPH. NADPH is used as a reductive reservoir of electrons to recharge antioxidants once they become oxidized. NADPH is also necessary to make your steroid hormones and fats.
Fill a small blender halfway with ice cubes, then add two organic free-range egg yolks, one whole avocado, one-half ounce raw cacao butter (not nibs), 1 to 5 tablespoons of MCT oil (optional; start low, like 1 teaspoon, and work your way up if using it), one-half teaspoon hydroxy methylbutyrate (HMB, a leucine metabolite that works just like leucine) and 2 to 3 scoops of collagen protein. Fill the blender with purified water. Blend well and eat with a spoon.
SOURCES AND REFERENCES
- 1 Journal of Applied Physiology March 2010;108(3):554-560
- 2, 24 Nat Rev Mol Cell Biol January 14, 2020 DOI: 10.1038/s41580-019-0199-y
- 3 Nutrients 2015 Jul; 7(7): 5712–5732
- 4 HRPlab.org June 28, 2014
- 5 International Journal of Sport Nutrition and Exercise Metabolism February 2012; 22(1): 11-18
- 6 The Journal of Nutrition August 2019; 149(8): 1326-1334
- 7 New York Times May 22, 2019
- 8 Biomolecules 2015 Jun; 5(2): 356–377
- 9 Archives of Medical Science 2015 Dec 10; 11(6): 1164–1178
- 10 Semin Cell Dev Biol. 2017 Dec;72:10-18
- 11 The Journal of Clinical Endocrinology & Metabolism October 19, 2019, DOI: 10.1210/clinem/dgz104
- 12 J Clin Invest. 1988 Apr;81(4):968-75
- 13 J Clin Endocrinol Metab. 1992 Apr;74(4):757-65
- 14 Science Daily December 4, 2003
- 15 Piedmont Healthcare, Best Exercises to Increase Testosterone
- 16 Triple Your T, Intermittent Fasting and Testosterone: The Ultimate Guide
- 17 Curr Neuropharmacol. 2015 Jul; 13(4): 536–542
- 18 Harvard Medical School, April 30, 2018
- 19, 23 Nutrition Express, Leucine Triggers Muscle Growth
- 20 American Journal of Clinical Nutrition, July 2017 Media Alert (PDF)
- 21 American Journal of Clinical Nutrition July 2017;106(1):12-13
- 22 Whey Protein Institute, Leucine Content in Common Foods (PDF)