By Dr. Mercola
Exercise is one of the "golden tickets" to preventing disease and slowing the aging process. One reason for this is because exercise is one of the most effective ways to regain insulin and leptin sensitivity and reverse insulin and leptin-resistance, which is a key to staying healthy as you get older.
But another reason why exercise is sometimes regarded as a real-life fountain of youth is because, when done intensely, it boosts your body's natural production of human growth hormone (HGH), a synergistic, foundational biochemical that addresses the serious muscle loss and atrophy that typically occurs with aging.
Intermittent fasting has many of the same benefits, including dramatically boosting HGH and optimizing insulin- and leptin sensitivity, which I'll discuss more toward the end of this article.
Recent research1 also shows that ingesting carbohydrates (sucrose) with added whey protein isolate during short-term recovery from 90 minutes of treadmill running increases the growth hormone response to a second exhaustive exercise bout of similar duration.
However, I've previously discussed the issue of implementing an exercise and diet plan based on your desired goal, either:
- Athletic performance, or
- Health, longevity and reproductive success
If you are seeking to optimize competitive athletics, then carb-loading as used in the featured study can be useful. However it is not a wise strategy if you're seeking long-term optimal health, as that requires a different approach. Avoiding carbs then becomes paramount, along with making sure you're using only high quality protein sources. (Clearly, competitive athletes could also improve if they used high quality organic, grass-fed whey rather than the far inferior whey protein isolate.)
Interestingly, in the wake of Lance Armstrong being stripped of his seven titles and banned from cycling for life after being found guilty of doping, one study known as the "Goldman Dilemma", showed that more than half of Olympic-level athletes would gladly use a drug that would kill them within five years as long as it guaranteed them a gold medal.2
To most people, however, this would be an unacceptable exchange. The featured approach clearly will not kill you in five years, and I suspect most of the adverse longevity consequences are reversible, but in my opinion carb-loading is not ideal for long-term health.
Why Carb-Loading is Not Recommended if You Exercise for Longevity
The idea behind carb-loading is to saturate yourself with carbs so your muscles will have plenty of glycogen to go on while you exercise. This works fine for really fit athletes that have an intense workout regimen. They also have the muscle mass that could accommodate large glucose surges as muscles can rapidly utilize glucose. Additionally most athletes have optimized insulin and leptin signaling and are exercising which also allows them to better use the carbs.
However, I believe it is totally inappropriate for the vast majority of non-athletes that exercise casually, or just to get healthy as their muscle mass isn't as well developed and their insulin and leptin signaling is typically impaired. Another point to consider in this study is that, while whey is great for stimulating muscle protein synthesis, I disagree with the use of whey protein isolate as whey protein concentrates are clearly superior.
As I'll discuss below, the focus on carbs is one of the most detrimental pieces of advice that is still widely promoted to athletes and non-athletes alike, and there are FAR better ways to boost HGH production than what was tested in the featured study, in which participants ran for 90 minutes with a four-hour long break in between repeated session.
First, it's important to remember that what you eat can either add to or detract from your exercise benefits, and if you're devoting the time to exercise for health and longevity, you'd be well advised to harness your meals to support your goals, not detract from them.
First and foremost, contrary to popular advice, to maximize the benefits of exercise you'll want to avoid fructose and other sugars unless you are engaged in intensive and prolonged cardio exercises that will allow you to burn these sugars, especially fructose, and not store them as fat.
However, exercise, which in and of itself improves insulin and leptin sensitivity, will NOT completely compensate for excessive use of fructose. This means that most casual exercisers and those seeking to improve their body composition and optimize health and fitness rather than boost athletic performance or competitiveness, need to ditch the energy drinks, sports drinks, most energy bars and even "healthy" drinks like vitamin water, as these will effectively sabotage your exercise benefits.
Fructose, which is found primarily in the form of high fructose corn syrup, is particularly detrimental as it tricks your body into gaining weight by turning off your body's appetite-control system. This happens because fructose does not appropriately stimulate insulin, which in turn does not suppress ghrelin (the "hunger hormone") and doesn't stimulate leptin (the "satiety hormone").
The end result is that you end up eating more, causing uncontrolled accumulation of sugar metabolites in your liver, which then leads to insulin resistance. Fructose also rapidly leads to decreased HDL ("good" cholesterol), increased LDL ("bad" cholesterol), elevated triglycerides, elevated blood sugar, and high blood pressure – i.e. classic metabolic syndrome. And if that's not bad enough, fructose has shown to increase the levels of TNF-α, a pro-inflammatory cytokine known to inhibit fat burning and promote muscle wasting.
Eating Whey Protein During Your Exercise Recovery May Boost HGH
Your production of vital human growth hormone increases by up to 771 percent during a high-intensity, interval workout like Peak Fitness because you are stimulating your fast twitch muscle fibers, which are rarely used during most exercise programs. The higher your levels of HGH, the healthier and stronger you will be.
Once you hit the age of 30, you enter what's called "somatopause," at which point your levels of HGH begin to drop off quite dramatically. This decline of HGH is part of what drives your aging process, so maintaining your HGH levels gets increasingly important with age.
Some athletes choose to inject HGH for its performance enhancing potential, though it is a banned substance in nearly every professional sport. I do not recommend injecting HGH however, due to the potential side effects, the cost and, more importantly, its potential to cause more long-term harm than good. Besides, as we now know, taking such risks is unnecessary because if you eat and exercise correctly, you will naturally optimize your HGH.
What You Eat in the Two to Three Hours After You Exercise is Extremely Important
After an intense workout, there's an exercise recovery phase of two to three hours during which you have to be somewhat careful about what foods you choose to eat. Specifically, in order to promote HGH release, you do need to restrict sugar intake post-exercise (although carbs can benefit those more interested in fast recovery, such as professional athletes). Fitness veteran Phil Campbell explains:
"What we recommend... is to get 25 grams of protein afterwards within that 30-minute golden window. There is a lot of research to support that, but there's also some research done by Dr. John Ivy of the University of Texas, a great researcher on a young cyclist who made recovery. They're not looking at growth hormone or maximizing growth hormone. They're trying to get to recover as quickly as possible so they can cycle several days in a row.
They showed that getting a ratio of 4:1 carbs to protein is better for recovery... 4:1 starts recovery faster. If you're going after recovery, that's the best strategy... [if] you're not looking for growth hormone, that is.
But on the other side, if your goal like most middle-aged adults and older is to maximize growth hormone, and to get this wonderful hormone circulating for that full two hours in the surging window for going after body fat (just about like you're doing cardio for two hours), you can do that. ...if you throw too many carbohydrates in... then that releases the hormones called somatostatin. That, for whatever reason, just shuts down growth hormone. That's clear in the research."
So it's important to avoid carbs, especially sugar or fructose-containing foods, in the two hours after your workout, and this includes sports drinks, to be sure you're getting the full HGH benefits. Consuming whey protein, however, appears to be nearly ideal, as it is a protein that assimilates very quickly, and will get to your muscles within 10-15 minutes of swallowing it, supplying your muscles with the right food at the right time to stop the catabolic process in your muscle and shift the process toward repair and growth.
Whey Helps With Muscle-Building, Too
An important review found that consumption of ~20–25 grams of a rapidly absorbed protein, such as whey protein, may serve to maximally stimulate muscle building after resistance exercise in young healthy individuals;3 high-quality leucine-rich proteins, such as whey, may be particularly important for the elderly to maximize muscle protein synthesis as well. Further, consuming whey not only immediately following your workout but also for up to 48 hours after resistance exercise may still offer some benefit:4
"...since resistance exercise increases MPS for up to ~48 h [hours] consumption of dietary amino acids 24-48 h post-exercise recovery would also likely convey the same synergistic effects on MPS [muscle protein synthesis] as those that are observed when amino acids are provided immediately after resistance exercise. The synergistic enhancement of pre-existing resistance exercise-induced elevations in MPS by protein provision is greatest immediately post-exercise and wanes over time, but may still be present up to 48 h later.
We have recently shown that feeding 15 g of whey protein, a less than optimally effective dose of protein for maximizing MPS, ~24 h after acute resistance exercise results in a greater stimulation of ...protein synthesis than the same dose provided at rest. ...We propose that there is, at least in young individuals, an extended 'window of anabolic opportunity' beyond the immediate post-exercise period that persists for at least 24 h..."
A recent study published in the journal Medicine and Science in Sports & Exercise demonstrated that consuming whey protein (20g protein / serving) 30 minutes before resistance training also boosts your body's metabolism for as much as 24 hours after your workout.5 In practical terms, consuming 20 grams of whey protein before exercise and another serving afterward will most likely yield the double benefit of increasing both fat burning and muscle build-up at the same time.
Intermittent Fasting: Another Way to Boost HGH Naturally
Just as combining whey protein with high-intensity exercise appears to work together synergistically to boost HGH production, so too does exercising while in a fasted state. Research has found that fasting raised HGH by 1,300 percent in women and 2,000 percent in men!6 And the combination of fasting and exercising maximizes the impact of cellular factors and catalysts (cyclic AMP and AMP Kinases), which force the breakdown of fat and glycogen for energy.
It's important to realize that this fitness-enhancing strategy is more about the timing of meals, as opposed to those fad plans where you essentially "starve" yourself for several days in a row.
On intermittent fasting, the longest time you'll ever abstain from food is 36 hours, although 14-18 hours is more common. You can also opt to simply delay eating. For example, skipping breakfast may be just the step to get you off a plateau in your fitness routine. Personally, I've revised my own eating schedule to eliminate breakfast and restrict the time I eat food to a period of about six to seven hours each day, which is typically from noon to 6 or 7 pm.
Intermittent Fasting for General Health and Longevity
There's plenty of research showing that fasting has a beneficial impact on longevity in animals. There are a number of mechanisms contributing to this effect. Normalizing insulin sensitivity is a major one as insulin sensitivity is critical for the activation of the mTOR pathway, which along with IGF-1 plays an important part in repairing and regenerating your tissues including your muscles and thereby counteracting the aging process. The fact that it improves a number of potent disease markers also contributes to fasting's overall beneficial effects on general health.
Even if you take the exercise component out, modern science has confirmed there are many good reasons for fasting, including:
- Normalizing your insulin sensitivity, which is key for optimal health as insulin resistance (which is what you get when after prolonged periods of over-secreted and elevated insulin) is a primary contributing factor to nearly all chronic disease, from diabetes to heart disease and even cancer
- Normalizing ghrelin levels, also known as "the hunger hormone"
- Promoting human growth hormone (HGH) production, which plays an important part in health, fitness and slowing the aging process
- Lowering triglyceride levels
- Reducing inflammation and lessening free radical damage
Tying it All Together
Whether you seek to optimize your athletic performance or health and longevity, incorporating 1-3 sessions of high-intensity exercises per week will help you achieve your aims by significantly boosting HGH production. Adding intermittent fasting can kick it up another notch. The same cannot be said for your diet, however.
Whereas carb-loading can be useful for professional athletes, those seeking health and longevity will not benefit from this strategy. On the contrary, severely limiting sugars and grains is part and parcel of any diet designed to optimize overall health and prevent chronic disease. Furthermore, it's important to note that consuming fructose within two hours prior to or after high-intensity exercise will nullify HGH production... So carb-loading while doing Peak Exercises will amount to wasted effort.