interval training????

I lost 20 pounds a few summers ago with just the first four weeks of Couch to 5K. It's great.
http://www.coolrunning.com/engine/2/2_3/181.shtml
It really eases you into running which is awesome cause when I started I couldn't even run for 30 seconds straight now I can go for five minutes at a fast pace easily and repeat it multiple times. There are tons of mobile apps that tell you when to walk/run too which you can use with your music.

It consists of doing easy work (Your max Heart Rate zone in the 50-60% category) for 3 minutes followed by starting from 1 minute (leading up to 3 minutes) of heavy work (so that you can barely breathe). Then repeat, over and over. I do 45 minutes of this twice a week. I do this on the recumbent bike. Other people do it running. On 3 of the days you are not doing this, you do say 5 miles running, or for me, 1 hr on the recumbent bike at easy pace. On the last day, you do a longer easy pace of 9 miles running or 90 min on the recumbent for me. Then you take a rest day. Be sure and space everything out accordingly. It is the best workout you can do to lose weight and it has worked tremendous results for me. This was told to me by my personal fitness trainer, who has a PhD. She knows what she's talking about! If you need help with the calculating of your max heart rate, it is 227 minus how old you are for women and 220 for men (minus how old they are). An app you can download will help you keep track of your heart rate and lead you through some interval training at an extra cost of $20 per year is Endomondo.

The only cardio I do is interval. I don't know how people can do 45-minutes of interval, that's amazing. I'm usually done after 15-20 minutes. :P

My treadmill interval is a 5-minute progressive warm-up. From 2.0mph to 4.0mph (increasing every 20-30 seconds) on an incline of 2.5 or 3.0. Then I run at 6.5mph for a minute. Then I drop down to 3.0mph for 90 seconds. Then I increase it back up to 6.5mph for a minute, then drop down to 3.0mph for 90 seconds. As I get better conditioned, I'll be able to do 45 seconds on, 45 seconds off. And I'll gradually increase the incline and my top speed.

A heart rate monitor is a good investment for interval. I use the Polar FT4 (youtube videos are helpful in seeing reviews/tutorials on how to use one).

I think if you incorporate 2 days of strength training (30-40 minutes) and 2 days of this interval cardio, you'll see some good results. You'll build lean muscle for toning and burn body fat.

Hope this helps! Good luck to you!

I do my internval training on the treadmill. It changes the incline and speed throughout the workout, they last from 20-30 min. I wasn't a big fan of using the treadmill before but I enjoy it with this traning in the winter. Good luck finding what is best for you.

I do my HIIT on a crosstrainer elliptical and it works great! Every two weeks I will increase the incline and the resistance and my intervals are 2 mins on and 30 secs on, and I do 14 intervals which comes out to be 35 mins flat. The elliptical lets you go as fast as you want, I try to keep it in the range on 300-320 rpms on the machine while I do my HIIT, which will definitely get me to my max heart rate. I found it really difficult to use a treadmill at my gym just because you have to do everything manually.