High Intensity Interval Training is the absolute best way to train no matter your fitness level, age or type of cardio you plan on doing.
Here are 3 things you want to know about interval training.
1. Keep an eye on your heart rate according to your age. Remember to keep your heart rate below 220 minus your age. This is your max number. So if you are 50 keep it below 170bpm.
2. Here is a great guide: Simply find your age and keep your heart rate between 55-65% in your rest work. And between 75-85% in your hard (interval) work.
3. The time allotted to the interval can vary. Depending on how you feel that day do about a 3-5 minute warm up and then push it hard enough to get your heart rate up to that 75-85% rate for at least 30 seconds or longer. Keep it up for about 20 minutes, no longer than 30 minutes. There is a reason for this and I will blog about it here.
This is the best type of exercise for your heart because it gets the heart rate up and brings it down. By doing this you get oxygen flowing through your body better. This is ideal for so many reasons. One of the added benefits of this is you burn more calories. But think of it like this you will feel so good because of the oxygen flow. Get there, do it!