If you simply increase your speed and stay there, while your body may,
overall burn some more calories, it won’t get that jolt.
Also bear in mind that interval training can indeed last longer than 30
seconds or a minute.
Some experts suggest that you can use interval training for 30-40 minutes,
depending on your state of health and what your overall exercise regimen
looks like.
The reason we’re focusing on 30 seconds to 1 minute is simply to give you
a clear understanding that interval training is a kind of mini training
within a training program.
And, as always, don’t overdo it with your interval training. Your goal here
is to become healthier and stronger, and lose weight in that process.
You gain nothing if you run so fast or bike so hard during interval training
that you hurt yourself. You will actually undermine your own health, and
possibly have to stop exercising while torn muscles or other ailments heal.
Variety
They say that variety is the spice of life, and this is indeed quite true. But
despite this awareness, many people don’t spice up their exercise
program; which is surprising, since doing so often leads to valuable
metabolism-boosting benefits.