By Dr. Mercola
Many people gravitate toward exercise because it can bring on welcome changes to your physical appearance – weight loss, firmer muscles, more toned legs, and less body fat, for instance.
But there are many more benefits from exercise that you can't see. These "invisible" benefits are just as important, if not more so, than the strictly aesthetic ones.
In fact, one study found that while many people started an exercise program to lose weight and improve their appearance, they continued to exercise because of the benefits to their well-being!1 How does exercise improve your life in ways you can feel but not necessarily see?
7 'Invisible' Exercise Benefits
1. Lessen Your Anxiety
Exercise has undeniable effects on your mood, with anxiety reduction key among them. A study by Princeton University researchers revealed that exercising creates new, excitable neurons along with new neurons designed to release the GABA neurotransmitter.
GABA inhibits excessive neuronal firing, helping to induce a natural state of calm.2 Commonly prescribed anti-anxiety drugs like Ativan, Xanax, and Valium actually exert a calming effect in this same manner, by boosting the action of GABA. The mood-boosting benefits of exercise occur both immediately after a workout and continue on in the long term.
In addition to the creation of new neurons, including those that release the calming neurotransmitter GABA, exercise boosts levels of potent brain chemicals like serotonin, dopamine, and norepinephrine, which may help buffer some of the effects of stress. Exercise is also one of the most effective prevention and treatment strategies for depression.
2. Boost Your Immune Function
When you exercise, you increase your circulation and your blood flow throughout your body. The components of your immune system are also better circulated, which means your immune system has a better chance of finding an illness before it spreads. This includes (but is certainly not limited to) seasonal colds and influenza.
According to a survey by the London School of Hygiene and Tropical Medicine, exercising vigorously for at least 2.5 hours each week can reduce your chances of catching the flu.3 The survey suggested that 100 cases of flu per 1,000 people could be prevented each year this way.
Other studies have also shown that regular exercise will help prevent the common cold. In one such study, women who exercised regularly were found to have half the risk of colds of those who didn't work out.4
And the ability of moderate exercise to ward off colds seemed to grow the longer it was used. The enhanced immunity was strongest in the final quarter of the year-long exercise program, suggesting that it is important to stick with exercise long term to get the full effects.
3. Sleep Better
If you're having trouble sleeping, an exercise program may be the solution. Research shows that regular exercisers report sleeping better, including falling asleep faster and having a decreased need for sleeping pills, than they did prior to the start of their exercise program.5
4. Reduce Symptoms of PMS
Women who exercise even report that their symptoms of PMS, including feeling irritable and bloated, improve. In fact, exercise was helpful for improving PMS symptoms in over 80 percent of those who tried it.6
5. Boost Your Sexual Health
Exercise is an important component of keeping your sex life alive, largely because it significantly lowers the risk of erectile dysfunction in men (and those who are the most active have the most benefit with better reported erections).
This works because exercise helps open your arteries, increasing blood flow throughout your body, including to the penis.7 Additionally, exercise helps with stress relief, improves your stamina and boosts your body image – all of which are conducive to a healthy sex drive.
6. Strengthen Your Brain
The increased blood flow that results from exercise also benefits your brain, allowing it to function better almost immediately. As a result, you tend to feel more focused after a workout.
Furthermore, exercising regularly will promote the growth of new brain cells. In your hippocampus, these new brain cells help boost memory and learning. As stated by the Huffington Post:8
"When you work out regularly, your brain gets used to this frequent surge of blood and adapts by turning certain genes on or off. Many of these changes boost brain cell function and protect from diseases such as Alzheimer's, Parkinson's or even stroke, and ward off age-related decline."
Exercise also encourages your brain to work at optimum capacity by causing your nerve cells to multiply, strengthening their interconnections and protecting them from damage.
There are multiple mechanisms at play here, but the rejuvenating role of brain-derived neurotrophic factor (BDNF) is one of them. BDNF activates brain stem cells to convert into new neurons. It also triggers numerous other chemicals that promote neural health.
7. Boost Your Body Image
Exercise helps your body to tone up and become leaner, but this benefit may pale in comparison to what it does for your body image. A meta-analysis of 57 studies found that exercise improves the way people feel about their bodies.9
Exercise Is One of the Best Preventive Medicines
A key health benefit of exercise is that it helps normalize your glucose, insulin, and leptin levels by optimizing insulin and leptin receptor sensitivity. This is a crucial factor for optimizing your overall health and preventing chronic disease, and may explain why exercise is such a potent preventive medicine. In fact, researchers recently suggested that exercise is "the best preventive drug" for many common ailments, from psychiatric disorders to heart disease, diabetes, and cancer.10 According to Jordan Metzl, a sports-medicine physician at New York City's Hospital for Special Surgery and author of The Exercise Cure:
"Exercise is the best preventive drug we have, and everybody needs to take that medicine."
Indeed, after reviewing 40 papers published between 2006 and 2010, researchers found that exercise reduces the risk of about two dozen health conditions, ranging from cancer and heart disease to type 2 diabetes, stroke, dementia, and depression. Exercise also slows down the rate of aging itself, providing perhaps the closest example of a real life fountain of youth as we will ever find. Besides optimizing insulin/leptin receptor sensitivity, other beneficial biochemical changes also occur during exercise, including alterations in more than 20 different metabolites involved in fat burning and metabolism, among other things. This includes changes in your:
- Muscles, which use glucose and ATP for contraction and movement. Tiny tears in your muscles make them grow bigger and stronger as they heal. Gaining more muscle through resistance exercises has many benefits, from losing excess fat to maintaining healthy bone mass and preventing age-related muscle loss as you age. The intensity of your resistance training can achieve a number of beneficial changes on the molecular, enzymatic, hormonal, and chemical level in your body.
- Lungs. As your muscles call for more oxygen, your breathing rate increases. The higher your VO2 max—your maximum capacity of oxygen use—the fitter you are.
- Heart. Your heart rate increases with physical activity to supply more oxygenated blood to your muscles. The fitter you are, the more efficiently your heart can do this, allowing you to work out longer and harder. Your blood pressure will also decrease as a result of new blood vessels forming.
- Joints and Bones. Exercise can place as much as five or six times more than your body weight on them. Weight-bearing exercise is one of the most effective remedies against osteoporosis, as your bones are very porous and soft, and as you get older, your bones can easily become less dense and hence, more brittle -- especially if you are inactive.
Have You Tired Peak Fitness Yet?
Compelling and ever-mounting research shows that the ideal form of exercise is short bursts of high-intensity exercise that I call Peak Fitness. Not only does it beat conventional cardio as the most effective and efficient form of exercise, it also provides health benefits you simply cannot get from regular aerobics, such as a tremendous boost in human growth hormone (HGH), aka the "fitness hormone." Plus, it takes only a fraction of the time of conventional workouts.
High-intensity interval training (HIIT) is key for reaping optimal results from exercise. There are many versions of HIIT, but the core premise involves maximum exertion followed by a quick rest period for a set of intervals. My Peak Fitness routine uses a set of eight 30-second sprints, each followed by 90 seconds of recovery, as taught by Phil Campbell who is a pioneer in this field. Also, while I typically recommend using an elliptical machine or recumbent bike, you can just as easily perform a high intensity routine without any equipment at all. The health benefits of high-intensity interval training are well-established at this point, and include:
Significantly improving your insulin sensitivity, especially if you're on a low-processed food, low-sugar/low-grain diet
Optimizing your cholesterol ratios, when combined with a proper diet
Boosting fat metabolism and optimizing your body fat percentage (as a result of improved conservation of sugar and glycogen in your muscles)
Virtually eliminating type 2 diabetes and high blood pressure
Naturally boosting your levels of human growth hormone (HGH)
Increasing your aerobic capacity
My Top Exercise 'Prescription' for Good Health
If you're ready to start exercising or want to make sure your program is allowing you to reap maximum benefits, both aesthetic and otherwise, please read my exercise guidance below. Ideally, you'll want to strive for a varied and well-rounded fitness program that incorporates other types of exercise as well, including "intermittent movement" during work hours to counteract the ill effects of prolonged sitting. I recommend incorporating the following types of exercise into your program in order to truly optimize your results:
- Avoid Sitting for More Than 15 Minutes. I usually set a timer for 15 minutes while sitting, and then stand up and do one-legged squats, jump squats or lunges when the timer goes off. The key is that you need to be moving all day long, even in non-exercise, or as I now like to call them, intermittent movement activities.
- High-Intensity Interval Training (HIIT): As mentioned, this is when you alternate short bursts of high-intensity exercise with gentle recovery periods.
- Core Exercises: Your body has 29 core muscles located mostly in your back, abdomen, and pelvis. This group of muscles provides the foundation for movement throughout your entire body, and strengthening them can help protect and support your back, make your spine and body less prone to injury and help you gain greater balance and stability.
- Stretching: My favorite type of stretching is active isolated stretches developed by Aaron Mattes. With Active Isolated Stretching, you hold each stretch for only two seconds, which works with your body's natural physiological makeup to improve circulation and increase the elasticity of muscle joints. This technique also allows your body to repair itself and prepare for daily activity. You can also use devices like the Power Plate to help you stretch.
- Strength Training: Rounding out your exercise program with a one-set strength training routine will ensure that you're really optimizing the possible health benefits of a regular exercise program. You can also "up" the intensity by slowing it down. For more information about using super slow weight training as a form of high intensity interval exercise, please see my interview with Dr. Doug McGuff.