• Don't overdo. Notice we said overload, not overdo. You want to feel worked out by the end of every HIT session but not so tired and sore that you can't press the button for the elevator, let alone walk up a flight of stairs without the help of your friends. Two HIT sessions a week is more than sufficient to get the job done; any more than that may leave you feeling burned out and overtrained. Listen to your body. It will tell you if you've gone too far and need to back off.

•Form is everything. Though you're pushing hard, you never want to lose sight of the fact that form is the most important aspect of this or any other form of weight training. A helpful hint: If you hear a lot of clanging and banging or your body is arching, swinging or moving in places that have nothing to do with lifting the weight, you need to re-evaluate your technique. Try lightening the load, slowing down and sharpening your mental focus.

• Buddy up. HIT is best done with a partner for two reasons: You can encourage and motivate each other to work harder than you could working out alone, and since you're using fairly hefty weights, you're going to want someone watching out for your safety. Choose a partner you trust and one you know you can push -- and will help you push yourself -- to the max. Or try hiring a trainer for a session or two.

• Stick to the basics. Because the aim of the workout is to work very hard, there's no need to get fancy. Stick with traditional weight-training exercises that don't have a big learning curve or require a lot of extra skill and coordination to pull off. Here's our recommended HIT list for both gym and home workouts. Do them in the order listed. There's no reason you can't mix and match exercises from each of the lists so long as you include one move for each major muscle group.