HIIT
When I was younger I used to do hill sprints to prepare for soccer and basketball season. I didn't know it then, but I was doing High Intensity Interval Training. I would sprint all out up the steepest hill I could find, maybe a tenth of a mile. I would then jog or walk down to recover, tag a telephone pole at the bottom, and sprint back up. Over the summer, I would gradually increase the number of reps. I might not have known what I was doing but I sure loved the results! By the time basketball season rolled around I was dunking with ease. Even though I barely touched a barbell as a teenager, these sprints gave me the best vertical jump of my life!
There is a lot you can accomplish with HIIT. When I look at videos on the web, mostly they're talking about fat burning and weight loss. To be honest, I don't much care. Fat/weight loss is more of a mathematical calculation of calories burned > calories consumed. Your diet and the things you do the other 23 hours you're not in the gym have more to do with that than the hour you spend training.
To me HIIT is the best way to train because I enjoy sports (basketball, soccer, hockey) that require maximal bursts of effort interspersed with relative rest. A game of basketball with its fast breaks and defensive slides broken up with free throws and time outs is like a long session of HIIT.
Now that I'm older and lazier, I've stopped those all out sprints up a hill and replaced it with less than maximum effort exercise interspersed with lighter effort and thought I was doing HIIT. Well, I"m not. I need to get back to the all out sprint sessions to train better for my sports, basketball.
So yeah, I've been doing it wrong....
Turns out what I thought was HIIT was really more like working at 75-85% of max capacity followed by some active rest. HIIT really needs to be all out 100% maximum effort until your lungs and muscles are burning, then rest enough until you can do it again. What I needed to do was reach that anaerobic stage where my muscles are generating lactic acid.
Not exercising to fatigue. Exercising to failure.
This probably can't be done very effectively in a gym. A good example of this would be a sprint/jog interval. Not something you could do on a treadmill. Stair sprints, like the hill climbs could push you into lactic acidosis until you descended for your rest. Burpees and jump rope might be able to get you there, but I don't feel like I'm pushing to 100% when I'm doing these exercises.
Make sure you are absolutely pushing yourself to the max during the high-intensity intervals (around 30 sec) for with rest periods long enough to recover (prob over 1 min). If you're not going all out then you're just doing sub-maximal high intensity interval training which is S.H.I.I.T. Here are some examples of HIIT programs.
Airdyne
Stair sprints
Bike sprints
I think the exercises need to be continuous motion, not staged like a burpee. Sure you can get your heart rate up, but you really want to be building up that lactic acid and pushing beyond your aerobic threshold.
