Building and maintaining muscle is necessary for all of us, especially as we age. And the earlier you start, the better. Most adults lose nearly a half-pound of muscle per year starting around age 25, mostly because they aren’t as active as they were when they were younger, according to the American Council on Exercise. And, of course, losing muscle at the same time that metabolism starts to slow down is a recipe for weight gain and the host of problems that come along with that.

Building stronger muscles isn’t just about vanity, either. Strength training not only helps with weight control, but it also stops bone loss and can even build new bone, reducing the risk of fractures from osteoporosis. It also improves balance and boosts energy levels.

Researchers seem to be constantly finding new reasons to do strength training. Some examples of recent findings include:

  • the more muscle men have, the lower their risk of death from cancer
  • that weight training strengthens bones, preventing bone loss and osteoporosis
  • weight training can improve long-term balance in older adults
  • weight training improves blood cholesterol levels
  • having muscle can improve insulin sensitivity and glucose tolerance

How much weight is best?

This depends on how many reps you're aiming for. You want to lift a heavy enough weight so that the last repetition is really tough — you feel like you couldn't do one more. Naturally, you'll need to use a heavier dumbbell for 6 reps than you will for 12, even though you're doing the same exercise. 

Which exercises are best?

The best exercises depend on your goals and how much time you have. You can do one exercise per body part, or you can do six. You can do exercises that focus on one muscle group or exercises that work several at the same time. The key is balance. It doesn't look too good to have a huge chest and weak back, and it’s also not healthy. When you work on one muscle, make sure you schedule a time to work on the opposing muscle.

All muscles are broken into antagonist pairs consisting of an extensor muscle and a flexor muscles. Some antagonist muscles pairs relevant to weight training are:

Muscles

Part of the Body

pectorals/lattismus dorsi

Chest/back

Anterior delts/posterior delts

Front of the shoulder/back of the shoulder

Trapezius/deltoids

Upper back/shoulder

Abdominus rectus/spinal erectors

Abdomen/lower back

Left and right external obliques

Left side of abdomen/right side of abdomen

Quadriceps/hamstrings

Front of thigh/back of thigh

Tibilias anterior/gastrocnemius

Shin/calf

Biceps/triceps

Top of upper arm/underside of upper arm

Beginners Workout

Here’s a workout designed for novices. All it takes is at least two half-hour sessions each week. Start with one set of eight to 12 repetitions for the first four weeks; when choosing weight, remember that the last two or three repetitions should be very difficult. Increase to 12–15 repetitions for the next four weeks. When performing 15 repetitions becomes easy, add a second set of reps (doing the same number of reps per set) or use a heavier weight. Be sure to take deep breaths while you are doing these exercises; always exhale during the exertion part (the “lifting” phase) of the move.  

Dumbbell chest fly (targets chest)

Lie on your back with a firm pillow under your head, shoulders, and upper back. Hold a dumbbell in each hand (start with 2–5 pounds). Push your arms straight up until your elbows are almost straight, palms facing each other. The weights should be directly above your shoulders. Inhale, and slowly lower your arms out to the sides, keeping your elbows slightly bent. Continue to lower until your elbows are slightly below your shoulders. Pause, exhale, and slowly close your arms back to the starting position.

Dumbbell overhead triceps extension (targets triceps)

Stand with your feet shoulder-width apart. Hold a dumbbell (start with 2–5 pounds) in each hand with your arms extended overhead. Without moving your elbows, slowly lower the right dumbbell behind your neck, pause, and then lift it to the starting position. Repeat with the left hand.  

Dumbbell shoulder press (targets shoulders)

Sit on a chair with back support, and put your feet flat on the floor. Hold a dumbbell in each hand (start with 2–5 pounds), and bend your arms so the weights lightly rest on your shoulders, palms facing forward. Push the weights up until your arms are straight, pause, and slowly return to the starting position.

Single-leg squat (targets buttocks, quadriceps, and calves)

Stand with your feet shoulder-width apart and your arms out to the side, raised to shoulder height. Lift your right leg out in front of you and slowly squat down, stopping when you feel like you’re losing your balance. (If you need help balancing, brace yourself by placing one hand on a wall.) Contract your leg and buttocks muscles to push yourself back to the starting position. Complete repetitions, switch legs, and repeat.

Safe and Effective Strength Training

People do the exact same routine in the exact same order for years. It can be comforting to master your program, but the problem is that your muscles adapt and get bored — and so will you. Every six to eight weeks you should tweak with the variables, including the sets and reps, the rest periods, the angles, the sequence, and the type of equipment. You should also keep the following tips in mind for a safer and more effective workout 

Never skip a warm up.

It's tempting to go straight from the locker room to the bench press, but you'll be able to lift more if you warm up your muscles with five minutes of aerobic exercise. Also, go easy on your first set of each strength-training exercise.

Don’t let momentum do the work.

When you lift weights too fast, you develop momentum, which can make the exercise too easy on your muscles. People are especially lax on the return phase of a lift — they'll hoist the dumbbells up slowly then let them come crashing down. Take at least two seconds to lift, pause for a second or two at the top of the movement, and take a full two seconds to return the weight to the starting position. 

Don’t hold your breath.

People forget to breathe when they lift, but you need as much oxygen as possible. Holding your breath or taking breaths that are too shallow can increase your blood pressure and zap your energy. Breathe through your mouth rather than your nose. For most exercises, exhale when you lift or press the weight, and inhale when you lower it. For exercises that expand your chest cavity, such as upright or seated rows, it's more natural to inhale as you lift and exhale as you release.  

Mix it up.

In order to keep making gains, you must vary your routine every six to eight weeks. For instance, increase the amount of weight you lift (increase by no more than 10 percent at a time), the number of repetitions, and reduce the rest time between sets from, say, 60 seconds to 15 or 30. How many repetitions is enough? You should be lifting heavy enough weight that the last two or three repetitions are very challenging; for most people that is in the 12-15 range.