Strength training is the process of building and maintaining muscles in the body by using progressively heavier weights (or resistance). It is also called resistance training, weight lifting, toning, and body building.

Strength training is very important for maintaining muscle mass throughout your lifetime. Muscle is metabolically active, which means it does the work of creating energy for your body by burning the calories you eat from food. When you maintain and build muscle, you’re letting your body do some of the hard work of maintaining your weight.

• Strength training increases the size and strength of muscles. The more muscle you have, the more calories you burn at rest. So, strength training is an important part of weight maintenance and weight loss.
• Strength training helps strengthen tendons, ligaments, and bones. This helps prevent injury during activities of daily living or physical activities.
• As we get older, muscle size and strength decline with age. But strength training exercises can rebuild and preserve muscles.
• Strength training also helps improves balance.
• Strength training can have a positive impact on your appearance.

The FITT principle can help you incorporate strength training exercise into your physical activity plan.

Frequency (how often you are physically active in a week)

It is recommended that you strength train your muscles at least two times per week. Rest at least one to two days in between working the same muscle groups again. For example, if you work your arm muscles on Monday, wait until Wednesday or Thursday to work them again. Small tears in the muscles occur during strength training. Rest is needed to allow the muscles to repair themselves, which is how they become bigger and stronger.

Intensity (how hard you work each time you are physically active)

If you’re new to exercise, figuring out how much weight to lift for each muscle group can be difficult.  It is a matter of trying different amounts and adjusting as needed. Start slowly, but keep in mind the weight should be high enough so that as you approach your last repetition, you feel muscle “exhaustion.”  This is when it is not possible to do even one more repetition with good form because the muscle is too tired. If you make sure you reach muscle exhaustion, your exercise will be more productive. 

Time (the duration or how long your physical activity lasts)

Aim to lift each weight for 8 to 15 repetitions (or “reps”), which equals one set. In general, more reps (about 10 to 15), and therefore lighter weights, are needed for general fitness and endurance. To build strength and muscle mass, aim for fewer reps (about 8 to 10) and use heavier weights.

If you are just beginning, try doing one set for each exercise. Most people work up to two sets at a time, with a 30- to 90-minute rest in between. While resting, catch your breath, stretch the muscle you are working, or get a drink of water.

No matter how many reps or sets, it is most important to lift to muscle exhaustion, which is when your muscles can’t possibly do one more rep. This helps build your muscles more efficiently during your work out.

Type (the kind of physical activity you are doing) 

Many types of exercises count as strength training. For example:

• Calisthenics use your own body as resistance to build strength. This is a great way for beginners to begin to build strength. Sit-ups, push-ups, arm dips, leg lunges, leg squats are examples of how to use your body weight as its own resistance.
• Resistance bands, which are large rubber bands that are used in various positions to work muscle groups, are another easy way to begin strength training exercises.
• Weight machines are also great for beginners. They usually have instructions and pictures, which show the muscle groups they are working. They are grouped together in a weight room and using each one ensures you work all muscle groups. They also provide structure for your body to be in good form while performing the exercise.
• Free weights are more advanced, but with guidance can sometimes be used for beginners if weight machines are not available.
• Whatever type of strength training you choose to do, don’t hold your breath. This is dangerous and may cause an increase in blood pressure. Exhale fully when you are lifting the weight. Inhale deeply when returning to the starting position, which is the easier phase.

It is most important to target all major muscles of the body, including the following:

• your arms (biceps and triceps)
• shoulders,
• chest and back,
• core (abs, obliques and lower back)
• legs (quads and hamstrings, glutes and calves)
• abductors and adductors (outer and inner thigh).

It is also especially important to work opposing muscle groups. For example, if you only work quads in the front of the thighs, and not the hamstrings in the back, then this may create imbalance and lead to injury or pain.