Intervals are good for performance reasons, but I've heard they may also help with weight loss. You burn a lot of calories, although very few of them come from stored fat, and you add muscle tissue, which helps change your metabolism over time. One study found that you might burn 36 % more fat per hour, after interval training. So, I'm wondering if this is something other Clydes and Athenas do?
Basically, interval training means going as hard as you can for a little while, then resting for a while - either by stopping all together, or pedaling gently for a bit. After that, you go all out again, then take another rest, repeat and rinse. As hard as you can should translate to your heart beating at 80+ % of its max, so this isn't for everyone. There are no rules on how long "a while" and "a bit" are, but the idea is that if you can do five minutes of high intensity pedaling without a break, you can do twenty with judicious resting during the same workout.
So, that's what I know about them. I'm hoping I can learn a bit more from other cyclist's experience to get the most out of my time on the bike. And to see how the stuff I do compares to the other Clydes and Athenas on the roads and trailways.
My answer is that I do these informally. I love to take long rides and rack lots of miles up, but I also enjoy Silly Commuter Racing ... and this works the heart. I ran an errand on the ride home on Tuesday, and challenged a few roadies. The ride included 16 minutes of aerobic exercise, 16 minutes of anaerobic, and 2 mins 30 seconds of red-line. But I didn't try to punctuate short bursts of work with short rests; I rode as hard as I could. After keeping my heart at 175 bmp for a while, I'd get exhausted and it would drop to "only" 160, but then I'd push harder after "resting" and make it up to 180 bmp. This guaranteed that there was no leap-frogging in any race. Yesterday, I did 10 more minutes at a very high intensity, and today I'll probably go kayaking and work my arms.