The Shape of Your Life is not perfect. We'd like to think otherwise, but now's the time to admit that no single strategy can work perfectly for every person, every time. Nor should it. To keep this program fresh, you need to make it your own, and some days you need to break the rules—within reason. Below, you'll find the 25 most important training fundamentals that we uncovered during the formation of the SYL program. Adopt them as general guidelines, and then apply them to create your own smart, rut-busting workouts.

GETTING STARTED
1) Create a goal that's not a number (160 pounds) or a look (rock-solid abs), but a state of mind or an achievement.
2) Periodize. Work in preset phases of intensity and always go easier before going hardest.
3) Schedule recovery time or schedule burnout. Strength grows during recovery.
4) Break workouts up when you need to. Studies show that ten minutes, three times a day, equals 30 minutes at once.
5) Practice complete workouts. Warm up first, and cool down and stretch when you're finished.

ENDURANCE
6) Go easy (little more than half of your ability or 60 percent of your maximum heart rate). Building endurance requires the patience to go slow.
7) To boost endurance, use intervals (short bursts over 75 percent of your maximum heart rate).
8) Manage your interval training wisely. First increase the number of intervals per workout (up to six), then their length (up to ten minutes). Then shorten the rests in between.
9) Build slowly. When increasing the duration or distance of your workout, don't leap more than 10 percent from one week to the next.
10) Put in the miles. If you plan on racing, you need to be running, swimming, or cycling 75 percent as much as you will on race day one month beforehand.

STRENGTH
11) Train movements—front-to-back (lunges), vertical (squats), and rotational (medicine-ball chops)—not body parts.
12) Practice form first. Three lifts done with good form are more productive than 30 done sloppily.
13) If you're new to a lift—or to lifting altogether—one set of 10 to 12 reps is fine to start.
14) Use your body weight for resistance when starting out. Push-ups, pull-ups, and dips are all you need to get going.
15) When you're ready for free weights, use dumbbells. They're safer and more challenging than barbells.
16) Let weight down slowly. Lowering is just as important as lifting.
17) Whenever possible, perform lifts on your feet or on a Swiss ball.
18) Remember these numbers: 10 and 20. For muscle strength, lift enough weight to wipe you out after 10 reps. For muscle endurance, perform up to 20.

FINE-TUNING
19) Treat stretching—and specifically yoga—as a workout itself, not a wrap-up.
20) Learn the the Sun Salutation. Try to finish every workout with five repetitions.
21) Work slow, be slow: Do power lifts, plyometrics, and agility drills to supplement your slower-speed core strength and endurance work.
22) Perform Olympic lifts, plyometrics, and agility drills when you're fresh—not when you're dog-tired after an endurance workout.
23) Work out in the morning. Excuses to skip a workout will be less likely to pop up, and you'll invariably end up feeling great all day.
24) Find a buddy. Having someone to work out with will keep you on track.
25) Whenever possible, take it outdoors.