Bodybuilding is great. Weight training is great. Crossfit, Pilates, plyometrics–they’re all great.

But some people just want to get stronger and fitter in a useful, “everyday life” kind of way. They don’t want to spend hours at the gym learning new exercisesand new routines.

If that’s you, here’s a foolproof workout plan that is guaranteed to work — as long as you stick with it.

The key is to focus on four basic exercises, and follow one simple principle.

First the exercises:

• squats;
• push-ups;
• dead lifts;
• pull-ups.

Squats increase leg and core strength. Push-ups increase chest, shoulder, and triceps strength. Dead lifts increase lower back, glute, and core strength (not to mention seemingly every other muscle in your body). And pull-ups increase back, shoulder, and arm strength (or you can reverse your grip and do chin-ups to engage your biceps more than your shoulders).

Do these four functional exercises and you’ll target the major muscle groups and build the kind of strength that makes everyday life easier. And, oh, yeah: Over time, you’ll not only be fitter, you’ll look fitter.

Now the guiding principle: Stick to just these exercises, and always do a little bit more each time you work out.

Why? Your body is superb at adapting. Do 100 push-ups a day for three weeks straight, and at first you will definitely get stronger, but eventually your body will decide that 100 push-ups a day is the new normal–and you’ll stop getting stronger. Do the same thing long enough and your body adapts. That’s why following the same routine, no matter what the routine, eventually results in a plateau.

To avoid a plateau, instead of changing exercises, the key is to change the loadyou put on your muscles.

Again: The best way to avoid a plateau is to follow a system that forces your body to adapt.

Let’s use push-ups as an example. Say you’ve been doing 10 sets of 10 push-ups, with a 45-second rest between each set. Next workout, increase one aspect: Do one more push-up per set, or rest for only 40 seconds between sets, or place a 10- or 25-pound plate across your back to add weight to the movement. Then, the next time you work out, do more push-ups per set, or maybe do one additional set of 10, or maybe rest even less. You get the point.

Just make sure you strategically change up the more. For example, you may start out doing seven pull-ups per set, then eight, then nine, then 10, but then, no matter how hard you try, you can’t do 11 pull-ups in a row.

No problem. Increase the load by doing fewer pull-ups per set while wearing a weight belt with a 10- or 20-pound plate attached to add resistance. Work on pulling up more weight for a week or two — and doing more reps each workout — and then go back to doing bodyweight-only pull-ups. I promise you’ll be able to do more than 10 reps per set because you will have forced your muscles to adapt and get stronger.

And while you may someday run into a wall that you just can’t overcome, that’s actually a good thing, because it means you’ve pushed your body close to its potential.

And then you can try doing some different exercises, and start the process all over again.

Try it: Do squats, push-ups, pull-ups, and dead lifts at least twice a week, preferably three times a week (until you’re doing so much that you need more time to recover). Stick to that schedule; if you don’t, your body won’t be forced to adapt.

In terms of reps, sets, and weight, begin however you want. If you start out too light or too easy, don’t worry–as time goes by and you add weight, reps, etc., your workouts will soon get hard.

Log each workout you complete, but more important, plan each workout ahead of time. Decide what you will do, and then do it. If you fail, fine. Try again next time. But don’t let “I’ll just do as much as I can today” be your plan. Decide exactly what you plan to do each workout. Then do it.

Think of it this way: Your long-term goal is to get stronger, but your immediate goal — your real commitment — is to complete every workout as planned, on schedule.