A guide to the free fitness app sports scientists just called the best

A little over a year ago, I picked out a selection of phone apps that would help someone get in shape, with apps designed to help facilitate exercise, meditation, healthy behavior, and good sleeping habits.

There's only one app on the list that I'm still using, and it's a free fitness app called Sworkit Lite (there's a paid version too).

It may seem like picking one fitness app to recommend out of the more than 100,000 health-related apps is an arbitrary decision, but it turns out my personal preference is backed by science: A team of sports scientists recently analyzed 30 popular free fitness apps and found that Sworkit Lite was the most closely aligned with the American College of Sports Medicine's training guidelines.

Those guidelines say a workout should include aerobic, strength and resistance, and flexibility components; it should follow evidence-based guidelines for frequency, intensity, and types of workouts; and it should include safety measures to help make sure beginners start at a safe point.

No app was perfect, the analysis found (and most were terrible). People with different goals will have different needs, and of course the best workout is whichever one you actually do. Other apps may be better, in fact, at motivating people to move.

But for me, Sworkit makes exercising easy and fun. It's basically like a playlist for fitness that you can just follow along. And now we know that its routines are expert-approved.

Here's how it works - and why I've stuck with it.