Every week, we’re bringing you a roundup of the latest health and wellness news to hit the wire. This week, we analyze whether 10,000 steps is a sound goal, the best sport for a longer life, and what a high-fat diet does to your brain.

Is 10,000 steps a good goal?

Millions of people around the world check their tracker daily, hoping to get in 10,000 steps. But is this number really the holy grail of health that it’s made out to be?

This article in The Guardian discusses the surprising and somewhat arbitrary origins of that number, which has since been adopted as the daily activity recommendation by the World Health Organization, the American Heart Foundation, and the U.S. Department of Health and Human Services.

Interestingly enough, that number came from a Japanese ad campaign tied to the 1964 Tokyo Olympics for a pedometer called a “manpo-kei,” or 10,000-step meter. There was no evidence for that level of activity at the time, says professor David Bassett, Ph.D., head of kinesiology, recreation and sports studies at the University of Tennessee. “They just felt that was a number that was indicative of an active lifestyle and should be healthy.”

Since that time, different studies have been conducted trying to determine whether 10,000 steps is optimal. But those studies have compared 10,000 steps with far lower numbers like 3,000 or 5,000 rather than 8,000 or 12,000 steps, which could be just as good or better than a daily 10K.

The question we should be asking, says one researcher interviewed, is how many steps are too few? With some studies suggesting that 6,000 to 8,000 steps have a protective effect against chronic illness, could a lower guideline do more to get people moving and improve public health?

Swing a racket, live longer?

Exercising solo is great, but if you want to live longer, team sports should be in the mix, according to the results of a study published in Mayo Clinic Proceedings, with tennis, badminton and soccer all better for longevity than cycling, swimming, jogging or time pumping iron.

It all boils down to the social aspect, study co-author Dr. James O’Keefe, a cardiologist at Saint Luke’s Mid America Heart Institute told Time. “If you’re interested in exercising for health and longevity and well-being, perhaps the most important feature of your exercise regimen is that it should involve a play date,” he says.

The study was based on data from 8,500 Danish adults who were questioned about their physical activity and asked to designate their primary form of exercise. They were monitored for about 25 years. The study found that compared to sedentary individuals, those who played tennis as their primary activity added 9.7 years to their life span, followed by badminton (6.2), soccer (4.7), cycling (3.7), swimming (3.4), jogging (3.2) and calisthenics (3.1).

Tennis likely took the top spot because it’s “highly interactive,” O’Keefe says, with players talking throughout. It’s a great way to foster connections, he says, which is turning out to be just as important to longevity as good cardiovascular health.

Why you’re still hungry on the keto diet

You’ve probably seen everyone from Halle Berry to LeBron James to Tim Tebow extolling the virtues of a high-fat, low-carb keto diet for weight loss, but new research mentioned in this Men’s Health story points to a potential problem—its ability to generate big cravings.

The research, published in the journal Science Translational Medicine, found that when mice were fed a high-fat diet, they were more likely to overeat. That’s because they had started producing a hormone called MMP-2, which blocked leptin (the satiety hormone responsible for telling you that you’re full) from binding to its receptors.

Of course, it was mice and not people studied, but researchers say this could point to why some people struggle with these types of diets, and it could help scientists one day formulate a pill that would block the troublesome MMP-2 so leptin-resistant dieters could feel full while losing weight.

Photo credit: Oliver Sjostrom, Unsplash