In 2010, an economist and a psychologist teamed up to determine the salary that would bring maximum happiness. The much-touted number they came up with was $75,000: people’s contentment would rise along with their incomes but only up to that threshold, at which point it would plateau or drop.
Our question: Is there a fitness equivalent to that perfect salary? Our health improves the more we exercise, but is there a point at which we start to get diminishing returns?
We spoke with a half-dozen experts to find an answer. Turns out there is such a thing as the “perfect” number of workouts, and such a thing as “too fit.”
It’s a safe bet that if you add muscle mass, you will be healthier. Take one 2016 paper in the American Journal of Cardiology that found that subjects with higher muscle masses had lower risks of mortality, regardless of their body fat percentages.
Jason Zhao, the clinical director at Therapeutic Associates Physical Therapy in Corvallis, Oregon, agrees that a targeted strength regimen to build and maintain muscle mass is needed for full-body fitness. But “it’s entirely possible to damage your organs, muscles, and joints, through excessive workouts,” he says. “Quite a bit of my patients come to see me because of over-use injuries.”
When it comes to weight training, the calculus on how much you should be doing and when is pretty straightforward, regardless of gender, according to the guidelines from the American College of Sports Medicine. You should lift at least two days per week and rest each muscle group for 48 to 72 hours before training it again. Use free-weights or do body-weight routines, as both will engage your stabilizing muscles. Limit your workout to 10 exercises of between eight and 15 reps each, depending on your age—if you’re younger than 45, aim for 8-12, older than 45, aim for 10-15.
Don’t worry if you’re not losing weight or reducing body fat: numerous studies have linked volunteers’ muscle strength—not just size—to lower risks of type 2 diabetes, cancer, stroke, vascular disease and heart failure. Simply lifting is the key, and there’s a formula on how to do it right.
“There’s no ‘ideal’ amount of muscle mass,” says Zack Papalia, the supervisor of Penn State’s Center for Fitness and Wellness. “But essentially, getting stronger equals getting healthier.”
As long-distance runners and cyclists know, muscle mass is just one-half of proper fitness. “Endurance is that second part of the equation,” says Christopher Lang Sr., an exercise physiologist at the California Health and Longevity Institute. “VO2 max is probably the best predictor of aerobic fitness and longevity.”
The healthiest way to strengthen your heart and shed some weight in the process is through moderate-intensity cardio, not extreme dieting, says Paulette Lambert, director of Nutrition at California Health and Longevity Institute. That “moderate-intensity” bit is crucial: you want to aim for 85 percent of your max heart rate—the threshold where you see the most health benefits.
Again, as with weight lifting, the guidelines here are simple: 30 minutes of exercise a day, for five days every week. A 2011 ACSM report notes that all-cause mortality starts to drop significantly if you follow this cardio regimen, while a 2001 study in Medicine & Science, Sports & Exercise, pegged the risk reduction at 20 to 30 percent compared to not exercising at all.
Of course, that’s the bare minimum. You must hit 300 minutes per week to, for example, decrease your chances of getting colon or breast cancer. That’s why we recommend power-walking or jogging for anywhere between 150 to 420 minutes (2.5 to seven hours) per week to get the maximum aerobic benefits.
Go past that seven-hour limit and you risk burnout and injury. Or at the very least, wasted time. A 2012 Mayo Clinic study notes that “further exertion” beyond one hour of vigorous cardio per day “produces diminishing [health] returns.” In 2011, papers in The Lancet and the International Journal of Epidemiology also noted that trend, as did a 2009 article in the International Journal of Sports Medicine.
“You’re just not gaining many more health benefits beyond that point,” says M. Brennan Harris, an associate professor of kinesiology at the College of William & Mary. “The injury rate continues to rise the longer you work-out, so the logic is, ‘Why exercise more when the risks begin to outweigh the rewards?’”
Of note, the Mayo Clinic determined that chronic training beyond that hour-per-day threshold may “cause adverse cardiovascular effects in some individuals,” such as a thickening of the heart valves, and a 2012 article in the British Journal of Sports Medicine concluded that long-term endurance training can cause heart damage.
But really, the biggest danger of overtraining is missing out on other activities.
“Being truly healthy means having a life outside the gym,” says to Lisa Hayden, a psychologist at the California Health & Longevity Institute. “There are lots of ways to estimate ‘ideal fitness,’ but having a positive life-balance is one of the most important. Keep that in mind, because it’s easy to overlook.”
Going Paleo may sound cool, but the most authoritative studies on the subject all vouch for the Mediterranean diet’s efficacy. It could add years to your life.
A 2008 meta-analysis in The BMJ found that those who followed the diet had a nine percent lower risk of all-cause mortality. Other recent studies have found that devotees are less likely to develop breast cancer, diabetes, heart disease, dementia, anxiety and depression. Plus, it also lowers blood pressure and inflammation.
“The diet varies slightly from region to region,” says Lambert, “but it’s uniformly plant based, and much healthier than the [Western diet] most Americans follow.”
The staples of the Mediterranean diet are vegetables, fruits, whole grains, nuts, legumes, fish, herbs, olive oil, and red wine, though eating poultry and dairy now and then is fine. Whenever possible, buy whole foods.
Each day, try to eat at least six to seven servings of fruit and vegetables, one serving of legumes, five to six servings of whole grains, and one handful of nuts. Oh, and drink one glass of red wine. Limit yourself to one to two servings of fish per week, and less than one serving of any other meat. (Before you set a calorie goal, visit a nutritionist.)
Imagine walking one mile on a rugged trail, then another mile on a sidewalk. On average, you’d burn 28 percent more calories during that hiking bit. And, depending on the dose, getting out in nature will boost your mental stability and cognitive fitness, too.
Recent studies published in Environmental Health and Preventative Medicine and Environmental Studies & Technology suggest that taking a five-minute stroll in nature will boost your mood and self-esteem, and that after another 10 minutes, your blood pressure, pulse and cortisol levels will start to drop. At 35 minutes, your working memory will have improved. A 50-minute dose will help prevent depression. On the far end of the spectrum, spending three or four days immersed in nature—without any technological distractions—can temporarily boost your convergent creativity by 50 percent.
“Most of the studies in this field seem to suggest a correlation,” says Peter James, an assistant professor at Harvard Medical School’s Department of Population Medicine. “Causality hasn’t been proven, but I suspect that in the future, urban greenspaces will be a necessity, not a perk.”
For our recommendations, we defer to Florence Williams, author of The Nature Fix. She suggests incorporating the shorter doses into your day but notes that it’s imperative to get out in nature for at least five hours every month.
“Being in the moment—hearing, seeing, smelling, and touching your surroundings—that’s key,” Williams says. “You won’t get the same benefits if you’re listening to your iPod, talking on the phone, or are otherwise distracted.”
Find a park near your office where you can take walking breaks during the day and also eat lunch. Five times per week, jog or walk briskly outside, off city streets, for about an hour. Spend a few days camping, even just from your car, every few weekends.
A 2015 study in Perspectives on Psychological Science identified loneliness, social isolation, and living alone as factors that raise our chances of dying early by 26 percent, 29 percent, and 32 percent, respectively.
According to a 2008 study in Brain, Behavior and Immunity, that’s because your fight or flight response kicks in when you feel lonely, upping inflammation and reducing antibody production. In the long run, chronic loneliness can cause neuroendocrine disorders, heart disease, stroke, and dementia.
“There is no [optimum] dose of social contact, in the same way that there is no perfect dose of medication that suits everyone,” says Susan Pinker, author of The Village Effect. “[Yet] the need for in-person social interaction is universal, even if the amount is individually set.”
There is, however, a limit to how many friends you should have. The theorized “Dunbar number”—which is really a series of numbers—suggests that our brains can only maintain 150 or so interpersonal relationships at any given time in our lives, give or take a few dozen.
But even if you thrive on meeting new faces, make time for the people who truly comfort you, and vice versa. A 2016 study in PLOS ONE found that loneliness—not social circle size, closeness with friends, or frequency of contact—is the strongest predictor of health.
“Not all relationships are equal,” says Julianne Holt-Lunstad, a professor of psychology and neuroscience at Brigham Young University. “The quality of your social interactions are what really matter. If you want to be healthy, that’s one of the first things to focus on.”