Whether you are an avid runner or just beginning, it is more than likely that you may want to take your cardio to the next level. And with the winter months approaching, you will most definitely want to stay indoors to do so.

Although there is much discussion as to whether running outdoors or indoors is essentially "better" for you, I have found that running inside on a treadmill has always proved to be more convenient, especially on my exercise equipment at home. And while the beautiful scenery remains outdoors, the incline changes that make for great cardio workouts may not exist right outside your door. However, they do on a treadmill.

So, if you are choosing to stay indoors, what are the best, most effective treadmill workouts?

One word: Intervals.

In order to burn fat during a cardio workout, you want your heart rate to speed up and slow down. For a treadmill workout, this happens when you spend a certain amount of time at one speed, then either increase or decrease it, and vice versa.

Here is an example of a beginner interval workout, where your highest speed reaches 7.2:

Minutes

Speed

1-3

3

3-5

3.5

5-8

6.5

8-9

7

9-10

3.5

10-13

6.7

13-14

7.2

14-15

3.5

15-18

7

18-19

6.5

19-20

3.5

You can see how the speed changes are sometimes a little drastic, but that is exactly what your body needs to get that heart rate going and blast those calories. And when you feel comfortable enough, you can gradually "up" the speeds listed in the chart, making your workout a little more challenging.

You also always want to keep your treadmill incline at least at "1"; this way, you are taking one extra step to challenge yourself (before you're ready to tackle the hill workouts, that is!). An interval workout can also be done by increasing or decreasing the incline, as well.

Another suggestion that I once came across for a good treadmill interval workout is to put together a treadmill playlist, and speed up or slow down according to the music. In this sense, you are paying less attention to what you are doing and more attention to what you are hearing.They have actually done studies that show this (Check Video)

All in all, a workout indoors or outdoors is beneficial to you. But personally, I like the control that a treadmill allows for me - the speed, incline, and if you're using a Yowza treadmill, such as the Daytona, it can even remember your workout for the next time you hop back on - (check it out in this USA-home-gym review). That way, you're not the one who needs to keep track of your progress - you just get to see the results.