Want to get stronger? Start with these 6 muscle-building exercises

This story is adapted from Life Kit's Guide to Building Strength, a five-day email series. Sign up for the special newsletter here.

There are innumerable ways to shape a workout routine for building muscle and strength, what's known as resistance training.

Over the years, I've experimented a bunch — hopping from one program to the next in search of the perfect formula. If it had some trendy-sounding name, even better.

Sure, this kept things interesting. But the consistent message from some of the leading experts in the world is that your workout doesn't need to be complicated.

If you want to tap into the many benefits of resistance training — for your cardiovascular health, metabolism, longevity and so on — the researchers who spoke with NPR all recommend prioritizing just a handful of exercises, at least when you're starting off.

These are called "multi-joint exercises," or "compound lifts," because they recruit one or more major muscle groups at the same time and involve at least two joints.

Nothing wrong with doing more targeted work like a bicep curl, which is an example of a "single-joint" exercise. But these can take extra time and may not be necessary, according to research.

6 essential muscle-building exercises 

Below, you'll find six recommended multi-joint exercises. Consider this a simple and efficient template for building your own workout routine. If these were all you did — and you did them consistently — you'd be all set.

Of course, you can add to that. "But 90% of what you need is that foundation," says Keith Baar, a muscle and tendon researcher at the University of California, Davis.

Our guide on form and technique is Mallory Mostov. She has coached strength and conditioning for nearly two decades and is one of the owners of Loft Fitness in Seattle.

She is using dumbbells, which tend to be easier and safer than barbells when you're new. You can also try variations of exercises with machines at the gym, if you prefer.

Scroll down for guidance on how much weight to lift, how many repetitions to do and how often to do these exercises.

1. Goblet squat

How to: Stand with your feet shoulder-width apart and your toes slightly out. Hold a dumbbell close to your chest. Take a deep breath and engage your core. Push your hips back and squat down while keeping your weight in your heels. Try to get your hips at or below your knee height. Push your heels into the floor, and squeeze your butt as you stand up.

Form tips: Keep your back extended, not rounded. Avoid shifting your weight into your toes. If your heels lift when you squat, bring your feet wider apart, or don't squat as low.

Variants:

• Bodyweight: squat with no dumbbell. 
• Machine option: seated leg press. 

2. Split squat

How to: Hold a dumbbell in each hand. Step one foot back, lifting the heel so you're on the toes. Drop the back knee down, tapping it on the floor (or on some other object like a yoga block if you can't reach). Lift that knee up vertically, keeping your hamstrings and glutes engaged. Do a set on each side.

Form tips: Keep your legs shoulder-width apart. If you feel it mostly in your back leg, lean your torso forward slightly to load the glute in your front leg.

Variants: 

• Bodyweight: Omit dumbbells 
• More advanced: Bulgarian split squat
• Machine option: single leg press

3. Row

How to: Rest one knee and one hand on a bench. Hold a dumbbell in your other hand, with your arm fully extended. Pull upward, squeezing the lat muscle in your upper back at the top. Lower slowly back down.

Form tips: Don't round your lower back — keep it lengthened and your core engaged. Think about pulling the dumbbell toward your belly button, with your elbows close to your sides.

Variants:

• Bodyweight: rows with towels and a door 
• Machine option: seated row

4. Bench press

How to: Lie on the bench with your feet on the ground. Start with a dumbbell in each hand, at your sternum level. Lift them up; extend your arms fully. Lower them back down with control.

Form tips: Don't let your shoulders crumple inward — lightly squeeze the shoulder blades together.

Variants:

• Bodyweight: pushups against a wall or while kneeling, or a full pushup
• Machine option: chest press 

5. Deadlift

How to: Stand with your feet at hip width. Hold dumbbells by your sides. Begin lowering the weights by pushing your butt out behind you as though you're closing a car door with it. Tap the weights to the floor. Push your hips forward as you rise up.

Form tips: Keep your back lengthened, with your neck in line with your spine. Keep your core engaged. As you stand up, push your heels through the floor. Don't let the weights drift out in front of you.

Variants:

• Bodyweight: glute bridge 
• Machine option: hamstring curl

6. Overhead press

How to: Sit on a bench, holding dumbbells by your shoulders. Push them both overhead, keeping your elbows close to your ears and your wrists stacked over your shoulders. With control, lower your arms back to your shoulders.

Form tips: Keep your lower ribs pulled in and your pelvis tucked. Avoid cranking your neck and looking up.

Variants: 

• Bodyweight: shoulder pushups 
• Machine: shoulder press 

A few notes: 

Correct form is paramount, especially to avoid injury. So if you're new to resistance training, take it slowly.

If you don't have dumbbells, try these with cans or other household objects. If you don't have a weight bench, use a sturdy chair, a coffee table or a piano bench.

How to pick your weights and reps 

Research shows you have lots of flexibility to use the weights and reps that make sense for you — provided you're pushing yourself enough.

Generally speaking, though, Brad Schoenfeld, a professor of exercise science at Lehman College in the Bronx, says aiming for roughly 8 to 12 reps of an exercise is a good starting point because it's efficient.

Don't hesitate to add or subtract reps to achieve the right amount of effort (more on that below).

How often to do this workout 

Even doing one set of each exercise once a week can be effective for the first three months of training. If you can, aim for two workouts and a total of 4 to 6 sets per exercise each week. (Note: Count the two squat variations as just one exercise since they're targeting the same muscle group.)

Take anywhere from 30 seconds to about 2 minutes of rest between sets. Stuart Phillips, a kinesiology professor at McMaster University in Canada, says you want to rest long enough that the next set feels productive and not rushed, but don't overthink it.

Go ahead, make an effort  

U.K.-based exercise scientist James Steele and other experts emphasize that effort is probably the "single most important determinant" in the muscle-building equation (along with actually showing up in the first place).

And this isn't some wishy-washy concept.

In resistance training, effort is usually measured by how close you are to failure, meaning the point where your muscles are so taxed they stall out and you have to stop to rest.

Studies find you don't need to go entirely to failure to get results, but you should be within a few reps or so.

Get stronger with Life Kit's 5-day newsletter series

There's a lot more you can do to personalize your routine based on these exercises, and evidence-based principles of how to build muscle and strength.

Sign up for Life Kit's 5-day email series, Guide to Building Strength, for more advice from fitness experts. Click here to join the newsletter now.

The digital story was edited by Malaka Gharib, Carmel Wroth and Meghan Keane, with art direction by Katie Hayes Luke. We'd love to hear from you. Leave us a voicemail at 202-216-9823, or email us at [email protected].

Listen to Life Kit on Apple Podcasts and Spotify, and sign up for our newsletter. Follow us on Instagram: @nprlifekit.