In the Milky Way, about 1 in 5 stars that are like our sun in size, color and age have planets that are roughly Earth's size and are in the habitable zone where life-crucial water can be liquid, according to intricate calculations based on four years of observations from NASA's now-crippled Kepler telescope.
Varying Incline. Varying the incline is another option for interval training using a good treadmill. Exercisers that want to vary the incline for interval training should still start with a warm up period, which should be a walk or slow jog at an incline of 1.0.
Interval workouts are a fun way to work on your speed. You can do track workouts, such as 400m (one lap around the track) repeats. After a five- to 10-minute warm-up, alternate between running one 400m at your 5K pace and jogging one slow, easy recovery lap.