A Collective Debunking Of Fitness Number Rules

Whether you source your health and wellness information from the Internet, your BFF, or even your local trainer or nutritionist, it can be difficult to differentiate fact from fiction – especially when it comes to specific, number-based claims. Because, while number rules certainly stand true in algebra class and engineering, some widely believed workout guidelines are actually fitness myths that trainers want people to stop following.

“You can find plenty of advice, recommendations, and tips and tricks out there, [but] it's important to be cautious and skeptical of anything that comes from a non-accredited source,” warns Annie Mulgrew, VP founding instructor of CITYROW. Believing common myths may be harmless in many cases, or even motivate you to get stronger on the fitness front, but some of them are simply not true — and can even be downright damaging to your health. Read on to hear experts debunk the top workout myths.

You Need To Get In 10,000 Steps A Day

At some point, 10,000 steps a day became the number to aim for in order to achieve ultimate health and longevity. However, according to experts — and science — that number isn’t necessarily a golden standard worth following. “This is not a one-size-fits-all approach,” says Sean Peden, M.D., an orthopedic surgeon and assistant professor at Yale School of Medicine. For most people, 10,000 steps a day ensures “reasonable activity, which is going to be good for mental and physical health,” he adds. But it might not be ideal for those with underlying conditions.

Mulgrew emphasizes that the most important goal should be simply moving your body. “Whether you get 10,000 steps or 5,000 steps in a day, the ultimate goal should simply be activity,” she explains. Of course, setting a goal of 10,000 steps a day is great if it’s achievable for you. “But you can also get the desired benefits from fewer steps as long as you are doing other forms of physical activity throughout the day,” says Mulgrew.

And if longevity is the goal, 7,000 steps per day will suffice, per a 2021 study published in JAMA Network Open, which found that middle-aged people who reached that goal were 50 to 70% less likely to pass on from any cause over the next decade in comparison to those who took fewer steps. Another study, conducted in 2019, found that women in their 70s who took just 4,400 steps a day improved their health when compared to those who took 2,700 or fewer steps a day.

Always Aim for 30 Minutes Of Cardio 5 Times Per Week

According to the U.S. Department of Health and Human Services’ Physical Activity Guidelines for Americans, 2nd edition, a minimum of 150 minutes per week of physical activity is recommended for maximum cardiovascular benefits. While most experts agree that this is a healthy goal, Mulgrew points out that not every cardio session needs to be a full-speed run on the treadmill. “Two or three of those days can be dedicated to higher intensities while the rest can simply be about staying active, like going for walks with the dog or weekend hikes with the family,” she explains.

You can categorize your physical activity by looking at your heart rate: During moderate-intensity activities, your target should be about 50-70% of your maximum heart rate, and 70-85% of your max during vigorous physical activity, according to the American Heart Association (AHA), which says your max heart rate is about 220 minus your age.

Examples of moderate-intensity aerobic activities per the AHA include brisk walking (at least 2.5 mph), water aerobics, dancing, gardening, tennis (doubles), and biking slower than 10 miles per hour, while vigorous can include things like uphill hiking, running, swimming laps, aerobic dancing, heavy yard work, cycling over 10 mph, tennis (singles), or jumping rope. So clearly you’ve got options when it comes to getting your cardio in. “People get very caught up in specifics, but I always want to encourage being more flexible when it comes to your exercise routine so that it feels doable and enjoyable rather than yet another thing on your to-do list,” says Mulgrew.

Drink At Least Eight Glasses Of Water Per Day

You’re told to drink water because, well, hydration brings numerous health benefits. “It dilutes toxins, improves digestive health, reduces headaches and muscle aches, improves athletic performance, and provides the necessary volume (liquid) for our organs to work properly,” explains Peden. That said, the widely held rule that one should drink eight glasses of water a day is a generalization that’s controversial, he says, because the exact amount needed for hydration and health purposes is determinant on a variety of factors.

“The amount of water necessary for each individual depends on their daily activity and sweat-loss volume,” says AKT master trainer Alissa Tucker. “It's important to consider how much you will be sweating on a given day and adjust your water intake accordingly. The more you sweat, the more water you need to consume.” An easy way to gauge hydration is by monitoring the color of your urine. “It should be clear or nearly clear. If it's on the darker side, you should consume more water,” says Tucker.

It’s important to note that those with specific health conditions or who are on particular medications may require more or less fluids, Peden points out. For example, congestive heart failure or kidney issues can cause your body to hold on to more moisture, resulting in overhydration, as can nonsteroidal anti-inflammatory medications. On the other hand, those with untreated diabetes or even a cold may be more prone to dehydration. There is such a thing as too much hydration. “Too much water can be damaging to the kidneys and could be dangerous,” adds Peden. Check with your doctor to see how much hydration is right for you.

A 60-Minute Workout Is More Effective Than a 10-Minute Workout

When it comes to exercise, does quantity always trump quality? According to Peden, it all depends on your health goals. For example, a daily 10-minute stretching or yoga routine could be better for back pain than a one-hour-long vigorous workout, he notes.

Tucker says that getting your heart rate up multiple times in a day via shorter workouts can be just as (and sometimes more) beneficial than one long workout. “In a shorter workout you may be able to push harder and get your heart rate higher than in a longer one,” she points out. “Multiple shorter workouts can help increase metabolism and burn more calories throughout the day.” This might also be a more realistic goal for some people who don’t have 60-minute chunks of their day to devote to exercise. “And any workout, even 10 minutes, is always better than no workout,” says Tucker.

If you can only do 10 minutes, Mulgrew recommends a HIIT workout so you can get the most out of that short amount of time. “Try doing a Tabata or EMOM (every minute on the minute) workout that requires you to work to a maximum intensity each round coupled with minimal rest,” she says.

Aim For A 2,000 Calorie Per Day Diet

The Dietary Guidelines for Americans recommends eating between 1,600 and 2,400 calories a day for women and 2,000 to 3,000 for men when on a healthy diet. However, caloric intake isn’t a one-size-fits-all number, according to Peden. He explains that how many calories you need in a day is dependent on a variety of factors, including your height, weight, and how many calories you are burning.

Also, Mulgrew notes that the quality of the food you are eating is more important than how many calories you’re intaking. “Once you figure out the right amount for you and your goals, make sure you are eating nourishing calories,” she points out. For instance, calories from organic proteins and vegetables and will have a much more beneficial effect on your long-term health, explains Mulgrew. The key, according to registered dietitian nutritionist Keri Gans, MS, RDN, CDN, is simply to make sure you eat enough to fuel your body so it performs optimally.

Studies referenced:

Jakicic, J. (2019). Association between Bout Duration of Physical Activity and Health: Systematic Review. Med Sci Sports Exerc. https://pubmed.ncbi.nlm.nih.gov/31095078/

Lee, I. (2019). Association of Step Volume and Intensity With All-Cause Mortality in Older Women. JAMA Intern Med. https://pubmed.ncbi.nlm.nih.gov/31141585/

Paluch, A. (2021). Steps per Day and All-Cause Mortality in Middle-aged Adults in the Coronary Artery Risk Development in Young Adults Study. JAMA Network Open. doi:10.1001/jamanetworkopen.2021.24516

Schmidt, W. D. (2001). Effects of long versus short bout exercise on fitness and weight loss in overweight females. J Am Coll Nutr. https://pubmed.ncbi.nlm.nih.gov/11601564/

Experts:

Sean Peden, M.D., orthopedic surgeon and assistant professor at Yale School of Medicine

Annie Mulgrew, VP founding instructor of CITYROW

Alissa Tucker, AKT master trainer

Keri Gans, MS, RDN, CDN, registered dietitian nutritionist