Question

I would like to know if working out on an eliptical machine between 45-60 minutes at about 6.0-7.5 miles per hour would be considered a high intensity workout comparable to Jogging or running or biking?

Answer

There is a lot of misinformation in the workout world about intensity. So in order to answer this question, and have it mean anything, first the word intensity needs to be defined.

Intensity = The level of demand that a given activity places on the body.

Trying to determine if using an elliptical trainer at 6-7 miles per hour is as intense as using an exercise bike or treadmill is irrelevant. The question you need to answer is this, "What is your goal while exercising?" If you know your goal, figuring out what intensity you need to be working at is easy.

Are you trying to increase your aerobic capacity? Are you training to lose body fat? Do you need to increase your time in short length sprints?

Train with your goal in mind and with some direction from someone who knows what they're talking about.  An aerobic conditioning plan should be structured around the following factors:

• your aerobic base
• your VO2 max
• your anaerobic threshold

I don't have time to get into all the finer points of cardio training here, but suffice it to say you need to be training with a heart rate monitor so you don't have to speculate about your intensity level, you'll know it instantly by looking at your wrist.  Don't ever rely on a subjective measurement like speed or incline or you're doomed to failure.