Interval training has become very popular these days, thanks to high-intensity interval training, or HIIT. Proponents of this type of exercise say it delivers many of the benefits of a much longer workout in a short, sharp burst.

The great thing about intervals is that you can do them with pretty much any type of exercise, including running, swimming and cycling. Interval training is also ideal for indoor workouts, like the cardio machines at your local gym. Or you can get creative and mix things up with a jump rope or weights.

Want to give it a go? If so, Apple Watch is the perfect workout companion for interval training.

The Activity Rings on your Apple Watch don’t provide a complete picture of your fitness. There is one important ring missing: Strength. The Rock didn’t get ripped just by standing up once an hour. And both the Exercise and Move rings essentially measure the same thing: cardio.

As any fitness expert will tell you, an effective workout program should combine cardio with strength training. Here’s why strength is currently Apple Watch’s weakness, and how you can use third-party apps to make sure it isn’t yours as well.

Millions of people go running with their iPhone or Apple Watch every day. Logging runs is one of the main features of just about every fitness gadget on the market.

So should you join the sweaty masses and start using a running app? Not so fast. Not everyone is suited to running, and it won’t develop all aspects of your fitness. Plus, there are loads of other kinds of exercise you could be doing instead. What makes running so special?