By Dr. Mercola
On average, Olympic medalists live longer than the rest of the population, although generally only by about three years. This was true irrespective of country, medal or sport, which makes sense since exercise is well known to extend longevity.
However, I've often described exercise as a drug that needs to be taken in the ideal dosage to impart the optimal benefit. Too little, and you won't get any benefit. Too much, and you could do harm.
Two recent studies in the British Medical Journal echoed these sentiments and found that, even among Olympic athletes, there can be too much of a "good thing."
Overly Strenuous Exercise is Not Necessarily Better
In the first study, which looked at the lives of over 15,000 Olympic medalists since 1896, researchers found that about 13 percent more athletes who competed in endurance sports (running, cycling) or mixed sports (cricket, golf, croquet) were alive 30 years after winning their medal, compared to non-Olympians of the same age and region.1
This was significantly more than among medalists in power sports (weight lifting and hammer throw), of which just 5 percent more were alive 30 years later compared to the control group.
Likewise, the second study, which included both Olympic participants and medalists, found that athletes in more strenuous sports (rowers, runners) lived similar lifespans to those who competed in less intense sports (golf, cricket).2 Furthermore, those who engaged in the most extreme contact sports, such as rugby or bobsledding (which involves frequent crashes), had shorter lifespans than other athletes.
So if you want to live as long as an Olympian, the most important factor seems to be the dedication to exercise, first and foremost. Engaging in the most strenuous types of exercise did not yield greater benefits in terms of lifespan, and in some cases, such as with power sports or contact sports, even shortened it. Researchers noted:
"Among former Olympic athletes, engagement in disciplines with high intensity exercise did not bring a survival benefit compared with disciplines with low intensity exercise. Those who engaged in disciplines with high levels of physical contact had higher mortality than other Olympians later in life."
When Exercise Causes More Harm Than Good …
Your body is meant to be active throughout the day, and it's also designed for intense, vigorous activity – although the latter appears best limited to short intervals instead of long, strenuous workouts.
Extreme endurance cardio, such as marathon running, actually damages your heart, and can negate the health benefits you'd otherwise reap from a regular fitness program. In the TED talk above, Dr. James O'Keefe, a research cardiologist and a former elite athlete, discusses the fact that extreme cardio can actually do more harm than good ...
As Dr. O'Keefe describes, extended extreme cardio sets in motion inflammatory mechanisms that damage your heart. So while your heart is indeed designed to work very hard, and will be strengthened from doing so, it's only designed to do so intermittently, and for short periods — not for an hour or more at a time. Repeatedly and consistently overwhelming the heart by long distance marathon running, for example, actually prematurely ages your heart.
Veteran endurance athletes have a five-fold increased risk of atrial fibrillation, a dangerous irregular heart rhythm. Worse yet, some endurance athletes also present ventricular tachycardia (a heart rhythm faster than 100-120 beats per minute), which can lead to ventricular fibrillation — a leading cause of sudden cardiac death.
According to a study presented at the Canadian Cardiovascular Congress 2010 in Montreal, regular exercise reduces cardiovascular risk by a factor of two or three. But the extended vigorous exercise performed during a marathon raises cardiac risk by seven-fold!3 Researchers found that during a marathon more than half of the segments in your heart lose function due to an increase in inflammation and a decrease in blood flow, and this temporary heart damage may play a role in marathon deaths.
Research by Dr. Arthur Siegel, director of Internal Medicine at Harvard's McLean Hospital, also found that long-distance running leads to high levels of inflammation that may trigger cardiac events,4 and a separate study published in Circulation found that running a marathon lead to abnormalities in how blood was pumped into the heart.5
Exercising in the "Goldilocks Zone" is Key
Too much of something that is normally good for you can have the reverse effect, actually causing harm in lieu of benefits. This is definitely true of exercise, and Dr. O'Keefe summarized the premise nicely in relation to runners. As he said, runners do live longer — in general, nearly 20 percent longer than non-runners. However, he described new research that found that, to optimize the health benefits from running, you'll want to run 5-20 miles per week — the ideal amount being 10-15 miles per week. Once you reach 25 miles or more per week, the benefits actually disappear!
Also, if you run too fast — over eight miles an hour — the benefits tend to go away (note we're talking about speed in long distance endurance running here, not interval sprinting). It won't make your health worse than a non-runner, but as Dr. O'Keefe says, if you put in that much effort, surely you'd want to get some benefit from it!
In order to obtain the health benefits and increased longevity from long distance running efforts, it seems best to limit your pace to six to seven miles per hour (about a ten-minute mile). Lastly, if you run seven days a week, the benefits also seem to disappear. The ideal amount was found to be between two to five days of exercise a week. Instead of trying to figure out the narrow window of therapeutic potential from long-distance running, a better alternative may be what's known as high-intensity interval training.
High-Intensity Interval Training: The Most Benefits in the Shortest Amount of Time
An accumulating body of clinical research now suggests that the best fitness regimen is actually one that mimics the movements of our hunter-gatherer ancestors, which included short bursts of high-intensity activities, but not long-distance running such as is required to complete a marathon. The idea behind "hunter-gatherer fitness" is to closely emulate the actions that ancient man took on a daily basis. This is what your body is hard-wired for, after all, and includes such attributes as:
- A variety of exercises performed regularly (weight training, cardio, stretching, etc.)
- Alternate difficult days with easier days
- Interval training sessions performed once or twice a week
- Weight training at least twice a week
- Ample time for rest after physical exertion
Your exercise program should be challenging, as it was for our ancestors, but it should not be excessive and it should be paired with ample time for recovery. Just as too much strenuous exercise can hurt your heart, too little will not be enough to give you the benefits. The good news is, the most recent research shows that relatively short bursts of intense exercise — even if done only a total of 20 minutes twice each week — can deliver many of the health and fitness benefits you get from doing hours of conventional 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." According to fitness expert Phil Campbell and author of Ready Set Go, getting cardiovascular benefits actually requires working all three types of muscle fibers and their associated energy systems -- and this cannot be done with traditional cardio. Here's a quick review:
- Slow twitch (red muscle): Activated by traditional strength training and cardio exercises
- Fast twitch (white muscle): Activated by high-intensity interval exercises (sprints)
- Super-fast (white muscle): Consists of fast twitch AND super-fast fibers, activated by high intensity interval exercises
Unfortunately, most traditional cardio and strength training exercises work only red muscle fibers, completely missing your white muscle fibers, which then atrophy. If your fitness routine doesn't work your white muscle, you aren't really working your heart in the most beneficial way. Your heart has two different metabolic processes: the aerobic, which requires oxygen for fuel, and the anaerobic, which does not require any oxygen.
Traditional strength training and cardio exercises work primarily the aerobic process and the slow twitch (red) muscle fibers. On the other hand, high-intensity interval exercises work your aerobic AND your anaerobic processes, which is what you need for optimal cardiovascular benefit. This is why you may not see the results you desire even when you're spending an hour on the treadmill several times a week. You're only working HALF of your muscle fibers!
In the case of these kinds of Peak Fitness exercises, less is more, as you can get all the benefits you need in just a 20-minute session performed twice a week. In fact, you should not do these exercises more than three times a week, as if you do it more frequently than that you may actually do more harm than good -- similar to running marathons or engaging in the more strenuous Olympic sports.
Simple Tips to Exercise for Maximum Longevity
If you are using exercise equipment, I recommend using a recumbent bicycle or an elliptical machine for your high-intensity interval training, although you certainly can use a treadmill, or sprint anywhere outdoors. Just beware that if you sprint outside, you must be very careful about stretching prior to sprinting. Also, unless you are already an athlete, I would strongly advise against sprinting outdoors, as several people I know became injured doing it the first time that way. For a demonstration using an elliptical machine, please see the video above. Here are the core principles:
- Warm up for three minutes
- Exercise as hard and fast as you can for 30 seconds. You should be gasping for breath and feel like you couldn't possibly go on another few seconds. It is better to use lower resistance and higher repetitions to increase your heart rate
- Recover for 90 seconds, still moving, but at slower pace and decreased resistance
- Repeat the high-intensity exercise and recovery 7 more times. (When you're first starting out, depending on your level of fitness, you may only be able to do two or three repetitions of the high-intensity intervals. As you get fitter, just keep adding repetitions until you're doing eight during your 20-minute session)
- Cool down for a few minutes afterward by cutting down your intensity by 50-80 percent
In addition to doing high-intensity interval exercises a couple of times a week, it's wise to alternate a wide variety of exercises in order to truly optimize your health. Without variety, your body will quickly adapt and the benefits will begin to plateau. Along with high-intensity interval training, I also recommend strength training, core exercises and stretching (especially active isolated stretches).