Many bodybuilders do cardio only by the clock. They know they have to hop on the treadmill and knock out 30 or 45 minutes' worth of plugging away, and they're done. Some more educated bodybuilders will occasionally attempt to tailor their program, opting for custom incline/intensity levels or perhaps keeping an eye on calories burned. The most intelligent bodybuilders will take heart rate into consideration when completing their cardio, in order to garner the most effective results.

Bodybuilders should be training at their optimal heart rate, which is 50 to 60 percent of their maximum heart rate. There are several steps to calculating this number.

- First, find your maximum heart rate (MHR). This is easy. Subtract your age from the number 220. If you are 30 years old, then your maximum heart rate is 220 minus 30, or 190

- Next, multiply your MHR by .50, and write down this number. This is you're your optimal minimum.

- Next, multiply your MHR by .60, and write down this number. This number is your optimal maximum.

Now, as you complete your cardio, try to keep your heart rate between your optimal minimum and optimal maximum. It's that easy!

In bodybuilding, "the more the better!" axiom often rings true. The more weight you lift, the bigger your muscles become. The more food you eat, the bigger you get. The more sleep you get, the better rested you become. However, in the case of cardio training intensity, more is not necessarily better. Training at heart rates of 70% or more will lead to the body consuming muscle to keep up with such an intense workload, instead of utilizing carbohydrates in the body or fat stores.

Training at levels of 50 to 60 percent is perfect for bodybuilders. If you find that 30 minutes at 50-60% is not leading to desired loss of body fat, raise the duration to 45 minutes, or use a split session (one in the morning and one following your weight training). If this additional cardio training does not help, it's time to re-evaluate your current diet and supplementation program. Cut daily calories by 300-500, add ECA or Tridenosen, and you should be on your way to a leaner physique.