Do the Brain Benefits of Exercise Last?

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March 22, 2013 • 44,043 views

Story at-a-glance

  • Two new studies have revealed that the brain benefits of exercise appear to quickly fade if your exercise program stops
  • In previously active rats, the brain benefits (both mood- and memory-related) started to fade within one to six weeks of not exercising
  • The results suggest that your body is designed for regular exercise, not sporadic or infrequent activity, and engaging in exercise throughout your life is likely to lead to the greatest gains
  • If you exercise regularly, you are not only supporting your brain health but also preventing and reducing chronic disease processes throughout your entire life

By Dr. Mercola

One of the many perks of exercising is that it is well known to support your brain health through BDNF (brain-derived neurotropic factor). This even spurs the creation of new brain cells (a process called neurogenesis).

Exercise boosts brain health through multiple pathways, including improving your hormone levels, increasing blood flow to your brain,reducing stress, and many others likely yet to be discovered.

The benefits of exercise can be felt rather quickly, which is great for motivation… but what happens if you stop exercising? As you might suspect, new research suggests your brain may quickly revert back to its pre-exercise state…

Move It or Lose It: You've Got to Keep Exercising to Sustain the Brain Benefits

If you work out religiously for three months, then suddenly stop for an extended period, your muscle tone will definitely suffer. This is one of the more obvious examples that your body is designed for regular exercise, not sporadic or infrequent activity.

Likewise, two new studies presented at the 2012 annual meeting of the Society for Neuroscience also revealed that the brain benefits of exercise also quickly fade if your exercise program stops.

In the first study, active rats that had a week of inactivity were pitted against completely inactive rats while performing memory tests. The previously active rats completed the tests much faster and had at least twice as many new neurons in the hippocampus region (the "memory center") of their brains. But remember, this was after just one week of inactivity.

At three weeks of inactivity, their new neurons began to decrease, as did their performance on the memory test. After six weeks of no activity, the neurons declined even more, as did their memory test scores, leading the study authors to suggest the "exercise-induced benefits may be transient."1

In the second study, rats that were active for 10 weeks, followed by three weeks of inactivity, had brains that were nearly identical to those of rats that had been completely inactive. In prior studies, it was shown that exercise had a favorable effect on the animals' moods, making them less anxious and more resilient to stress. However, the new research suggests that such benefits "wear off quickly." As the first study's senior author noted:2

"Brain changes are not maintained when regular physical exercise is interrupted… though our observations are restricted to rats, indirect evidence suggests that the same phenomenon occurs in human beings."

It's Not Too Late to Get Moving!

While the benefits of exercise might fade fast, they can also be achieved relatively quickly. Exercising – even briefly – can change your DNA in a way that readies your body for increased muscle strength and fat burning. It also boosts your natural human growth hormone (HGH) production, which is important for maintaining muscle mass as you age. If you're approaching middle-age or beyond, you might be thinking that it's too late for you to get in shape, but this is not the case.

Remember, you are never too old to start exercising.

In fact, exercise gets even more important with advancing age. Research shows that, no matter your age, you stand to gain significant improvements in strength, range of motion, balance, bone density and mental clarity through exercise. It's also been revealed that if you're fit at 50, you're much more likely to be healthy into your 70s and 80s.

According to new research, men and women who'd been the least fit in their 40s and 50s developed the most chronic conditions early in the aging process, including heart disease, type 2 diabetes, Alzheimer's, COPD, kidney disease, and lung or colon cancer.3

Essentially, being physically fit "compresses the time" you are likely to spend being debilitated during old age. Clearly, exercising throughout your lifespan is highly beneficial, and the earlier you start, the more profound the benefits will be. It makes sense, then, that if you exercise regularly, you are preventing and reducing chronic disease processes throughout your entire life. This will make a major difference in your quality of life at all ages …

More Exercise Isn't Necessarily Better

One of the most common reasons why people give up on exercise, and therefore lose out on all of its priceless benefits, is a lack of time. So if you think you need to spend an hour pounding the treadmill every day in order to be fit, then you'll be pleased to learn this is an outdated myth.

Research has disproven it many times in recent years, such as in one study that found those who spent 30 minutes per day exercising lost more weight than those who spent a full hour at it every day.4 While it may be counterintuitive, the results showed moderate exercisers got more for their effort – they lost more weight in half the time.5

So it really is possible, and imperative, to fit regular exercise into virtually any schedule. Previous research has shown that just 20 minutes of high-intensity interval training, two to three times a week, can yield greater results than slow and steady conventional aerobics performed five times a week.

A Fitness Plan to Live By

The more active you stay, the better your brain (and overall health) is likely to be. This includes not only specifically engaging in exercise and other physically demanding activities but also making an effort to sit less. To get all the benefits exercise has to offer, you'll want to strive for a varied and well-rounded fitness program that incorporates a variety of exercises. As a general rule, as soon as an exercise becomes easy to complete, you need to increase the intensity and/or try another exercise to keep challenging your body. I recommend incorporating the following types of exercise into your program:

  1. High-Intensity Interval (Anaerobic) Training: This is when you alternate short bursts of high-intensity exercise with gentle recovery periods. In the video below, you can see a demonstration of this in action using Peak Fitness.
  2. Strength Training: Rounding out your exercise program with a 1-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 below.
  3. Download Interview Transcript

  4. 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.
  5. You need enough repetitions to exhaust your muscles. The weight should be heavy enough that this can be done in fewer than 12 repetitions, yet light enough to do a minimum of four repetitions. It is also important NOT to exercise the same muscle groups every day. They need at least two days of rest to recover, repair and rebuild. Exercise programs like Pilates and yoga are also great for strengthening your core muscles, as are specific exercises you can learn from a personal trainer.

  6. 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.
  7. Foundation Exercises: One of the things I do to compensate for the time I spend sitting each day is to regularly do Foundation exercises developed by a brilliant chiropractor, Eric Goodman. These exercises are used by many professional and elite athletes, but more importantly can easily address the root cause of most low back pain, which is related to weakness and imbalance among your posterior chain of muscles. It is easily argued that these imbalances are primarily related to sitting.

[+]Sources and References [-]Sources and References

  • Studies presented at the 2012 annual meeting of the Society for Neuroscience, October 13-17, 2012 New Orleans, LA
  • NYTimes.com January 9, 2013
  • 1 NYTimes.com January 9, 2013
  • 2 NYTimes.com January 9, 2013
  • 3 Arch Intern Med August 27, 2012
  • 4 Am J PhysiolRegulIntegrPhysiol August 1, 2012
  • 5 The Atlantic August 27, 2012