Timing

When I design training programs I play with sets, reps, load, tempo, rest intervals, just like I hope every other trainer or trainee does, whether aware of it or not. Becoming truly aware of those components is what will distinguish a brilliant working plan from a plan that will just work, compared to no plan.
It's been long since I sat and thought of that specifically, but I've had exceptionally great workouts in the past few days thanks to my new toy, the Timex Ironman Triathlon.
The manual was too long for the technically challenged, so I went to the good part that explained laps and split timing and I was done! I easily figured out that little girly watch can time 100 laps,remember 50 of them and make all the right noises! Funny enough, seems like time goes by faster! Talk about time perception and distortion!
Unlike loads and sets and reps, rest intervals and tempo are often overlooked. You never hear anyone say: oh yeah and I rested for 30 seconds between sets of squats and pull ups today! Most trainees will brag about their numbers and will rest until they are done talking, reading, switching songs on their i pods or when they feel like it's time to start. And that's absolutely fine, unless you are actually training for something.
Rest will always be based on your primary goal, whether it's strength, energy hypertrophy, or different types of endurance. Then rest will be based on your loads and the primary requirements of your sport or event. You won't take 30 second breaks preparing for a maximum lift, nor will you take 5 minute breaks getting ready for a kick boxing match.

Here is a quick recap of major RI schemes:

reps 1><3><6><10=><12=>12 = 30'-60' RI
Energy System Training = maximum rest interval equals max length of maximum effort, try to decrease RI each training micro-cycle.

Learning to time your rest intervals is just as crucial for training success as are reading the numbers on the weight plates and learning proper form. If you are not doing it, start doing it today. Match your goals to your rest intervals, then time, then adjust accordingly the next time you plan a change in your training program.