Interval training consists in running fast and slow, repeatedly. Intervals helps you get in shape and run faster in next races. RunCalc can help you with this training, signaling when you should start running faster (single whistle sound) and when you can rest (double whistle sound). You set when to start interval training (e.g. after 1-mile warm-up) and determine interval and pause time. Then you can run 1 mile cooling down. RunCalc will continually measure time, distance and speed, and you will be able to analyze your achievements on graphs on RunCalc portal, all within one training session.

You can configure interval training in Intervals menu, where you set interval and pause time. You can do it whenever you want during your training. Click OK and from this moment on the app will be giving whistle sounds when you should start interval or rest.

You can put smartphone into your sachet and don't have to look at it - just listen. Earphones are not necessary - the sounds should be loud enough - whistles like PE teacher's in primary school - do you remember that? ;-)

When you forget to count intervals, you can check it on smartphone screen (intervals on the left, pauses on the right).

When you finish your interval training, go to Intervals again and click Reset. From now on the app will not whistle, but give sounds according to GPS autolap distance.

I recommend running intervals and using RunCalc to help with this :-)