Strength Training: What It Is, Its Benefits and How to Start

In short

Strength training is any exercise where your muscles work against resistance, such as dumbbells, a barbell, machines, resistance bands or your own body weight, to build strength, muscle and endurance. Research links it to stronger muscles, better physical function, stronger bones in some groups and fewer symptoms of depression and anxiety. To start, train your whole body two or three days a week, do 2 to 3 sets of 8 to 12 reps per exercise, and add a little weight or a rep when the last set gets easier.

Dreaming of a muscular, lean body? Do you want to reduce body fat, build muscle and use more energy through the day? Strength and resistance training can support all of these goals; for fat loss, your eating matters most. Besides building a muscular body, resistance training has many health and mental benefits.

In this guide I explain what it is, what the research says about its benefits, how its main principles work, and how you can start this week, at the gym or at home. Let's start with the question: what is strength training?

What is strength training?

The general definition of strength training is any physical movement in which you use your body weight or equipment (for example, dumbbells or resistance bands) to build muscle mass, strength and endurance. Strength training is also known as weight training, resistance training and muscle training.

Common forms include:

• Free weights: dumbbells, barbells and kettlebells.
• Machines: such as the leg press, the chest press or the cable station.
• Body-weight exercises: push-ups, pull-ups, dips, squats, planks and more.
• Bands and suspension straps: resistance bands and TRX straps.

First, let's start with the benefits.

The benefits of strength training

Strengthening the body and building muscle mass

The body becomes much stronger because of weight training. Everyday tasks get easier: lifting heavy objects, carrying heavy groceries and even playing with the kids.

This benefit is the obvious one, but it should not be ignored, especially as we get older and naturally begin to lose strength and muscle mass. The 2026 position stand of the American College of Sports Medicine (ACSM) reviewed 137 systematic reviews with more than 30,000 healthy adults. Compared with no exercise, resistance training clearly improved muscle strength, muscle size, power, endurance, walking speed, balance and several measures of physical function.

When you lift weights, your muscles work against a load they are not used to, and the body adapts by building muscle tissue, a process called hypertrophy. It means an increase in muscle mass over time.

Strength training raises self-confidence

Many people start training just to build self-confidence. Strength training can give a significant boost to self-confidence.

Training helps us overcome challenges, develop self-discipline and work toward a goal. In addition, it can increase your sense of self-efficacy: the belief that you are able to succeed at difficult tasks.

Improves mood, reduces symptoms of depression and helps with anxiety

Many people start weight training mainly to look better, but they stay with it for the mental and emotional benefits. A 2018 meta-analysis in JAMA Psychiatry pooled 33 randomized trials with 1,877 adults. Resistance training was linked to a moderate drop in depressive symptoms, whether or not the participants were healthy, and whether or not their strength improved much. The authors noted that trials with blinded assessment showed smaller effects and called for better-quality trials.

A 2017 meta-analysis of 16 studies (922 adults) by the same research group found that resistance training also reduced anxiety symptoms, with a small effect overall and a larger one in healthy participants.

Your body uses a little more energy

The more muscle mass you build, the easier it gets to manage your body fat. The reason is simple: muscle tissue burns more calories than fat tissue, so more muscle raises the energy your body uses at rest. A 2010 study of 131 healthy adults, which measured organ and tissue sizes with MRI, confirmed the commonly used estimates: at rest, skeletal muscle uses about 13 calories per kilogram per day, and fat tissue about 4.5 (slightly less after age 50).

Keep that difference in proportion: 2 kg (about 4.4 lb) of new muscle adds only about 26 calories a day at rest. The bigger effect comes from the training itself and from staying active. Losing fat still depends mainly on eating fewer calories than your body uses.

Strengthens bones and joints

Yes, it's true: lifting weights doesn't only strengthen the muscles. It also helps improve bone and joint health. Physical activity is immensely important for fighting the natural weakening of the bones that happens with age.

Strength exercises put temporary stress on the bones, and send a message to the bone-building cells to start strengthening the bones so they adapt to the load. Strong bones reduce the risk of osteoporosis (loss of calcium and thinning of the bone), fractures and falls, especially as you get older.

In the LIFTMOR trial, 101 postmenopausal women with low bone mass did either 8 months of supervised, heavy strength and impact training (twice a week, 30 minutes) or a light home program. Compared with the light program, the heavy training group (5 sets of 5 reps above 85% of their one-rep max) had better bone density results in the lower spine and at the hip, and did better on every physical function test. It was closely supervised, and it was one group of women, so it is not a template for lifting that heavy on your own.

What the health guidelines say

The World Health Organization's 2020 guidelines recommend that adults do muscle-strengthening activities at a moderate or greater intensity, working all major muscle groups, on 2 or more days a week, in addition to their aerobic activity (150 to 300 minutes of moderate activity or 75 to 150 minutes of vigorous activity a week). The same guidelines link regular physical activity in adults to a lower risk of death from cardiovascular disease and fewer new cases of high blood pressure.

The 4 principles of strength training

1. Overload

The basic principle of strength training is repeatedly overloading a muscle group. Usually you do it by contracting the muscles against heavy resistance and returning to the starting position for a number of repetitions until failure (the point where you can't do another good rep).

During strength training, microscopic (really tiny) tears can occur in the muscle fibers. After training, the muscles want to adapt to the load, so the body repairs the tears, and the muscles grow and become stronger. A 2018 review argued that muscle damage is not what drives growth: what matters is a challenging load that grows over time as you get stronger. This is called progressive overload.

Most professional bodybuilders don't like to reach failure, because it takes a long time to recover when the body gets there. They usually get close to failure. The ACSM 2026 position stand supports this: training to momentary muscle fatigue did not consistently change the results.

2. Intensity

When we talk about the intensity of training, we mean the amount of work required to achieve an effective workout for a particular person. Training intensity varies between people, according to their level of physical fitness.

It can be expressed in working weights, training volume and training frequency.

3. Volume

Training volume is the number of sets and repetitions a person does for a muscle group in a workout. Different goals require different rep ranges. These are the common guidelines for the number of repetitions in each set:

• Building strength: 1 to 5 repetitions
• Building muscle mass (hypertrophy): 8 to 12 repetitions
• Building endurance: 15 or more repetitions

These ranges are guidelines, not hard borders. In one small study, 18 trained young men did 3 sets of 7 exercises, three times a week, for 8 weeks, with either 8 to 12 or 25 to 35 reps per set, taking every set to failure. Both groups built similar muscle. The heavier group gained more squat strength, and the lighter group gained more muscular endurance. The ACSM 2026 position stand points the same way: heavier loads (80% of your one-rep max or more) built more strength, and 10 or more sets per muscle group per week built more muscle.

4. Training frequency

Here I measure training frequency by the number of days between training a certain muscle and the next workout of that same muscle. For example, if you train your chest only on Mondays, your training frequency for chest is once a week.

The more advanced you become, the more the training frequency goes up. This happens because you will need more time to recover. Research gives you room to choose: a 2019 review of 25 studies found that when the weekly sets were equal, training a muscle more often made little difference to muscle growth. For strength, the ACSM 2026 position stand found better results with at least two sessions a week.

How to start strength training as a beginner

Step 1: Choose your days

Start with two or three full body workouts a week, with at least one rest day between them. Two days already meet the WHO minimum. My full body workout plan gives you a ready plan, and the guide on how to make a workout plan explains when to move to a split.

Step 2: Cover the main movements

Pick one exercise for each basic movement:

• Squat: a goblet squat or a body-weight squat.
• Hinge (bending at the hips): a Romanian deadlift with dumbbells.
• Push: push-ups (on your knees or against a bench if needed) or a dumbbell press.
• Pull: a dumbbell row or a lat pulldown.
• Core: a plank.

Step 3: Set your sets, reps, effort and rest

Before your first exercise, warm up for about five minutes (brisk walking, cycling or easy movements), then do one light set of your first exercise. Start with a light weight until the movement feels steady, control the weight on the way down as well as on the way up, and breathe out as you push or pull.

Step 4: A sample beginner week

Alternate workout A and workout B: for example A on Monday, B on Wednesday and A on Friday, then B, A, B the next week. In your first week or two, do 1 to 2 sets of each exercise, then move to the sets shown.

Step 5: Progress a little at a time

Use a simple rule. Pick a rep range, for example 8 to 12. When you reach 12 reps on every set with good form, add the smallest weight step you have next time, and work back up. With body-weight exercises, add reps first, then make the exercise harder (for example, from knee push-ups to full push-ups). Here is an example log for a dumbbell row once you are doing 3 sets:

Log every workout. A bad day happens; look at the trend over several weeks. Once you train with heavier weights, a one-rep max calculator can help you follow your strength in your main lifts.

Strength training vs aerobic training

When it comes to specific types of physical activity, you can't really compare one to another. Each type of activity has different goals and achieves different results. Aerobic training has other benefits, for example:

• Improves lung function and endurance.
• Improves heart and blood vessel function and reduces the risk of heart disease.
• Reduces resting heart rate and lowers blood pressure.

If your goal is building muscle mass, you must do resistance training. In addition, you can combine aerobic training once in a while. If you enjoy it and it suits you, it's the right thing for you. For general health, the WHO recommends both.

Common myths

Myth 1: To do strength training you must train in a gym

This is a very common myth, that strength exercises can only be done in a gym. Of course this is not true, there are plenty of options for resistance training. You can do bodyweight workouts and do strength exercises like push-ups, pull-ups, dips, planks and more.

In addition, you can train with resistance bands, loop bands or TRX straps. You can do a home strength workout, and it's even free. Here is how the options compare:

For ideas, see my guide to home workout exercises. In a 2015 study of 30 trained students, push-ups with elastic bands and the bench press, done at comparable muscle activity, built similar strength over 5 weeks. It was one short study in young trained people, but it shows that bands can be a real training tool.

Myth 2: Strength training for women will make them big and bulky

This is perhaps the most common myth there is when it comes to strength training for women. You can hear so many people who think this way. Many times, this is the reason women don't want to train with heavy weights.

It's true that on social media you can see female bodybuilders who are very muscular, but they get there in a particular way. It takes many years of dedicated training and nutrition, and in competitive bodybuilding some athletes also use performance-enhancing drugs, to reach the very large physique seen on competitors.

A woman's body naturally produces much lower levels of testosterone than a man's, and that makes building very large muscles much harder. A 2020 meta-analysis of studies in young and middle-aged adults found that women and men gain muscle at a similar rate relative to where they start, and that women gained relatively more upper-body strength. Because most women start with less muscle, the change in absolute size is usually modest. Women who train and eat well can build a strong, fit body and enjoy all the health benefits that resistance training has to offer.

Myth 3: A high number of repetitions is good for getting lean

Nothing could be further from the truth. Light weights can be useful for improving muscle strength and endurance. But if you want to get lean, you need to lose fat. There is one way to do that: you need to eat fewer calories than your body uses. A BMR calculator gives you a starting estimate of your energy needs, and my guide to bodybuilding nutrition gives you 9 simple rules to build on. The training itself should still be challenging, whatever your rep range.

What to eat before and after strength training?

A very common question is what to eat before and after strength training. There are a lot of myths on the subject, but a meal before and after training helps many people. To get the most out of a strength workout, it is important to get the right nutrients into your body before training: carbohydrates and protein.

Carbohydrates help the body fill the glycogen stores (the energy store in the muscle). Eating protein helps improve protein absorption in the muscle, and so supports the recovery process.

Before training

You can eat anywhere from three hours to 30 minutes before training. If you eat 2 to 3 hours before, you can have a large meal with complex carbohydrates and protein, for example:

• Rice and chicken
• Pasta and meat
• Sweet potatoes and fish

If you eat closer to the workout, eat a little. Try to eat foods that digest easily, such as fruit and a protein shake. You can also drink coffee half an hour before training; many people find that it gives them more energy for the workout.

After training

After training you can eat fruit to fill the glycogen stores quickly, and this way you will avoid excessive fatigue after training. In addition, a common guideline is to eat about 20 to 30 grams of protein after training. It is very important to make sure to eat after training, especially if you didn't get to eat protein two hours before the workout.

You eat the serving of protein in order to help the body switch from a state in which the muscle is breaking down to a state in which it repairs itself. It is better to eat a fast-digesting protein such as whey protein, which is found in protein powder. Sleep and rest days are part of the program too.

Safety

Start lighter than you think you need to, and let the weight earn its way up: add a little only when you reach the top of your rep range with good form. Control the weight on the way down, and keep your rest days, since muscles get stronger while you recover. Stop a set when your form starts to slip, even if you planned more reps, because a clean rep counts for more than an extra messy one. On a day you are tired or sleeping badly, go lighter or do fewer sets instead of pushing through. With heavy barbell lifts such as the squat or bench press, use safety arms or a spotter, and when you change the weight or the exercise, build back up with a lighter warm-up set first.

Bottom line

Beyond building a fit, muscular body, strength and resistance training has many health and mental benefits. And the beauty is that they suit almost everyone.

Many people miss out on the benefits of strength training in favor of aerobic training, especially women. Some women are afraid that strength exercises will build them big, massive muscles. Of course this is not true and you have nothing to worry about: very large muscles take years of dedicated training, and the research above shows that women gain at a similar relative rate to men, starting from less muscle.

Over time, with steady training, most people notice an improvement in strength and muscle mass. As your muscle mass goes up, you will likely be able to lift more weight, which helps you keep building muscle. When you are ready for a full plan, read my guide on how to make a workout plan, and if your main goal is muscle size, continue with hypertrophy training.

Frequently asked questions

Is resistance training the same as strength training?

In everyday use, yes. The terms overlap: "resistance training" describes the method (muscles working against a load), and "strength training" often describes the goal of getting stronger.

How often should a beginner do strength training?

Two or three full body workouts a week, with a rest day between them. The WHO recommends at least two days a week for adults.

How many sets and reps should a beginner do?

Start with 1 to 2 sets in your first weeks, then 2 to 3 sets of 8 to 12 reps per exercise, stopping when you could still do 2 to 3 good reps.

What are the benefits of strength training?

Research links it to more strength and muscle, better physical function and balance, stronger bones in some groups, and fewer symptoms of depression and anxiety.

Can I do strength training at home?

Yes. Body-weight exercises, dumbbells and resistance bands all work. Make the exercises harder as you get stronger.

How long until I see results from strength training?

Beginners often feel stronger within a few weeks, partly because they learn the movements. Visible changes in muscle usually take longer, often a few months of steady training, and they vary a lot between people.

Does strength training help with weight loss?

Weight loss depends mainly on eating fewer calories than you use. Strength training adds strength and muscle, so many people keep it up while they lose weight.

Is strength training safe for older adults?

The WHO recommends muscle-strengthening activity for all age groups, including older adults. For older adults, the WHO also recommends balance and strength activities on 3 or more days a week. Start light and learn the movements first.