williamw30 saidHi Guys. I had a great workout this morning. I used the elliptical machine for about 20 mins and kept my heart rate at my max of 170 bpm. Question- how long should I stay at my max for good cardio training?
Depends on your age and how much weight you want to lose, but I do believe 20 minutes per session is at best a minimum for getting anything meaningful out of cardio.
I've lost about 65 lbs in the last 7 months, and to do that I've used the Karvonen method of figuring out the correct range I should be working in.
So because I'm 34 and have a resting heart rate of 53 bpm, my min/max training heart rate is 133-159 bpm. When I'm on the elliptical, I aim to be between 140 and 150 bpm for a good 40-45 minutes, and it's worked so far!
(Here's a Karvonen calculator for you -- http://www.polar-heartrate-monitors.com/heart_rate_calculator.asp
Even though you're 30, 170 bpm seems a little high to me, and 20 minutes seems a little brief, but you've probably got less weight to lose than me. If the minimum for cardio is 20 minutes in your training range, I always like to go above the minimum, so maybe 30 minutes would be good for you. You should also be aiming for a range, not a set number, because you'll never be able to hit the same exact number every day. It's just the way the body works.
Also, were you on the elliptical for 20 minutes total, or did you maintain a heart rate of 170 bpm for at least 20 minutes in addition to any warmup and cooldown time? Any cardio time below your target range doesn't count!
I'm also curious as to whether you're using a personal heart rate monitor or the one on the machine, because the monitors built into the machines are crap. Once I got my own monitor with a chest strap, I saw how wildly inaccurate the machine's monitor can be. So if this is something you're serious about, I'd recommend plunking down the cash for a decent heart rate monitor.