A crucial part of any well-rounded fitness program is the inclusion of cardiovascular work. Cardio gives numerous physiological benefits and should not be avoided.
The Cardio Routine
The first step for a good cardio workout is to obtain your maximum heart rate(MHR). This is done by taking the number 220 and subtracting your age. So let's say that you are 30 years old...
220 - 30 = 190
Your MHR is 190. Now, to ensure aerobic adaptations, you want to maintain a heart rate of about 70-85% of your MHR for at least 20 minutes.
190 * 0.70 = ~130
190 * 0.85 = ~160
For beginners, I recommend starting at 70% of MHR for 20 minutes, 3 days a week on the days you are not weight training. You want to gradually build up to 45 minutes of consistent cardio with your heart rate in the 70-85% MHR the entire time.
Note: some obese people should choose a lower impact machine other than treadmill. Something like the elliptical machine or recumbent bike will work well.
You can choose any machine you like, but the important thing is to maintain your 70-85% MHR for at least 20 minutes. This requires monitoring your heart rate. You can use the sensors on the machine of your choice or you can use a heart rate monitor watch. The ones made by Polar are excellent.
An Example of the Routine
So, using our 30 year old man as an example, let's walk through his cardio routine.
Figures his heart rate needs to be between 130-160 from the calculations above.
Jumps on treadmill or other machine.
Gradually warms up to speed that feels a little tough, around 5-6 on a scale of 1-10.
Checks heart rate: only at 115. Needs to increase speed or intensity.
After 2 minutes, checks it again: Now at 170. Too high, needs to reduce speed or intensity.
After 2 minutes, checks it again: Now at 145. Perfect. Maintain in this range for 20 minutes. Checks every 2 minutes to ensure that heart rate is where it needs to be.
After 20 minutes is up, lower speed significantly and cool down for 5 minutes.
Get off of machine.
Progression
Progression is simple enough. Every week simply add 1 minute to the time you are on the machine, up to a maximum of 45 minutes.
A Final Note
You don't have to do 20-45 minutes all at once. You could split up the workout so that you do 10 minutes at a time, 2-4 times a day. Just make sure that cumulatively, you have 20-45 minutes for the day of cardiovascular exercise at 70-85% MHR.
Next up I'll talk about basic nutrition and what you should be eating for maximum results.
Simple and concise.