Why Exercising Harder Isn't Always Better
A well-balanced exercise regimen is the key to optimal health
Of all the factors that go into a workout, exercise intensity can be the trickiest to get right.
If you don’t push yourself a little bit, you won’t burn many calories and you’ll miss out on the biggest potential health benefits.
But if you overdo it, you could increase your risk for injury. Recent studies have even found that exercising at a high intensity too often can have negative long-term health consequences.
Slow and Steady Wins the Race
Danish researchers conducting the Copenhagen City Heart Study kept track of more than 5,000 healthy individuals since 2001 to see what impact various lifestyle behaviors had on mortality rates.
The research results, published in the Journal of the American College of Cardiology this past February, found a U-shaped relationship between the dose of jogging to mortality rates. Put simply, those who jogged frequently for longer periods of time and at higher intensities were about as likely to die as those who didn’t jog at all. But the individuals who jogged only two or three times per week, for 30 to 45 minutes, at slow speeds of around 5.0 mph had the lowest mortality rates.
Other research also supports a philosophy of moderation where strength training is concerned. Scientists writing for the American Society of Exercise Physiologists published research earlier this year showing that among middle-aged men, two strength training sessions per week were as effective as four when it came to producing strength gains.
Meanwhile, researchers in the UK found that the time of recovery needed between intense bouts of exercise increases as we age. The younger men in their study needed only three days to recover from an intense workout, while the older men required five days.
Not an Excuse for Slouching
Please do not take the information above to mean that you should exercise less—the opposite is true!
While a recent 15-year study concluded that certain health benefits can be realized from as little as five minutes of jogging per day, the overwhelming health problems facing our nation are due in large part to our sedentary lifestyles. The vast majority of Americans over 50 do not meet the minimum healthy standards for frequency, duration or intensity of exercise.
The point I’m trying to drive home here is that a well-balanced exercise regimen that includes some high-intensity exercise and lots of moderate-intensity activity appears to be the key to living a longer, healthier life.
What’s the Right Balance?
The one thing that is clear from all of the research on exercise, health and longevity is that consistency is key. Doing some activity nearly every day is necessary to maintain good health and functionality.
Fortunately, that activity doesn’t have to eat up a large chunk of your time. Accumulating 30 to 45 minutes of moderate-intensity exercise in bouts as short as 5 to 10 minutes is adequate.
For generally healthy adults over 50, a well-rounded program should include lots of moderate-intensity aerobic activity, a regular routine that promotes flexibility and range of motion, and some resistance training in order to maintain strength and muscle mass. A whole body strength training circuit that targets all the major muscle groups performed twice per week is adequate.
If you aren’t familiar with strength training exercises, it’s imperative that you take a class or hire a trainer to get started. In terms of flexibility and mobility training, yoga, tai chi, qi gong and traditional static stretching exercises are all good options.
Get Off the Chair
While an exercise habit is very important, it’s even more critical that you reduce the amount of time you spend sitting each day. A recent study published in the Annals of Internal Medicine found that sitting for prolonged periods has serious negative metabolic consequences that you can’t undo even if you exercise every day. So set an alarm, wear an activity tracker, get rid of all the chairs in your house - do whatever you have to do to stop sitting so much!
When to Up the Intensity
Finally, if you are healthy enough for it, working a little bit of high-intensity exercise into your weekly regimen can pay off in a big way. In a paper published by the American College of Sports Medicine last year, Norwegian researchers found a direct positive correlation between cardiorespiratory fitness (as measured by VO2Max, or maximal oxygen uptake) and longevity. And there’s no better way to boost VO2Max than by pumping up the intensity of your workouts once in a while. Research has found that High-Intensity Interval Training (HIIT) is more effective for improving cardiorespiratory fitness than continuous moderate exercise.
A HIIT workout involves alternating short bouts of very high-intensity exercise, such as sprinting, with longer bouts of very low-intensity exercise, such as slow walking, within the same workout. The key is to keep the work intervals very short (30 seconds or less), the rest intervals relatively long (1 - 5 minutes) and to limit the frequency of HIIT workouts to one or two per week. It’s also important to note that HIIT workouts usually require a higher-impact activity, such as running or jumping, and an adequate fitness level to begin with, so they are not for everyone. You should consult with your doctor before incorporating HIIT into your exercise regimen.