Reference Guide to Strength Training
An In-Depth Look
By Jen Mueller and Nicole Nichols, Fitness Experts
SparkPeople’s Exercise Reference Guides offer an in-depth look at the principles of fitness.
Every movement we make—from walking to driving—involves our muscles. Muscles are unique. They have the ability to relax, contract, and produce force. They are metabolically active, meaning that the more muscle you have, the more calories your body uses at rest and during exercise. Your muscles are highly responsive to strength training, which helps them to become larger and stronger.
But if you don’t know anything about strength training, where do you start? Right here! This guide will tell you everything you need to know to begin and even offer a few tips for experienced exercisers as well.
What is Strength Training?
Strength training is the process of exercising with progressively heavier resistance for the purpose of strengthening the musculoskeletal system. It is also referred to as weight lifting, weight training, body sculpting, toning, body building, and resistance training.
What are the Benefits of Strength Training?
Regular strength training increases the size and strength of the muscle fibers. It also strengthens the tendons, ligaments, and bones. All of these changes have a positive impact on your physical fitness, appearance, and metabolism, while reducing the risk of injury and decreasing joint and muscle pain.
Muscle is metabolically-active tissue. This means that the more muscle you have, the faster your metabolism is while at rest. So, strength training is an important component of weight loss and weight maintenance.
Without consistent strength training, muscle size and strength decline with age. An inactive person loses half a pound of muscle every year after age 20. After age 60, this rate of loss doubles. But, muscle loss is not inevitable. With regular strength training, muscle mass can be preserved throughout the lifespan, and the muscle lost can also be rebuilt.
4 Principles of Strength Training
The four principles of strength training are guidelines that will help you strength train safely and effectively to reach your goals.
1. The Tension Principle: The key to developing strength is creating tension within a muscle (or group of muscles). Tension is created by resistance. Resistance can come from weights (like dumbbells), specially-designed strength training machines, resistance bands, or the weight of your own body. There are three methods of resistance:
Calisthenics (your own body weight): You can use the weight of your own body to develop muscle, but using body weight alone is less effective for developing larger muscles and greater strength. However, calisthenics adequately improve general muscular fitness and are sufficient to improve muscle tone and maintain one’s current level of muscular strength. Examples include: pushups, crunches, dips, pull ups, lunges, and squats, just to name a few.
Fixed Resistance: This method of resistance provides a constant amount of resistance throughout the full range of motion (ROM) of a strength training exercise. This means that the amount of resistance/weight you are lifting does not change during the movement. For example, during a 10-pound curl, you are lifting 10 pounds throughout the motion. Fixed resistance helps to strengthen all the major muscle groups in the body. Examples include: Exercises that use dumbbells (free weights), resistance bands and tubes, and some machines.
Variable Resistance: During exercises with variable resistance, the amount of resistance changes as you move through the range of motion. This creates a more consistent effort of exertion throughout the entire exercise. For example, when lifting weights, it is harder to lift up against gravity and easier to lower the weight down with gravity. Specially-designed machines (like Nautilus and Hammer Strength brands) take the angle, movement, and gravity into account so that the release of a biceps curl feels just as hard as the lifting phase of the curl.
2. The Overload Principle: In order to build strength, your muscles must work harder than they are accustomed to. This “overload” will result in increased strength as the body adapts to the stress placed upon it. Everyone begins at a certain level of strength. To become stronger, you must regularly increase the tension (weight or resistance) that your muscles work against, causing them to adapt to a new level. As the muscles respond to an overload, they will grow in size and strength. There are two types of strength overloads:
Isometric means “same length.” This is a high-intensity contraction of the muscle with no change in the length of the muscle. In other words, your muscles are working hard but the muscle itself remains static. Isometric exercises are good for variety and some strength maintenance, but they don’t challenge your body enough to build much strength. Learn more about isometric exercise here.
Isotonic means “same tension.” When you lift weights or use resistance bands, your muscles are shortening and lengthening against the resistance. This challenges your muscles throughout the entire range of motion. However, the amount of force the muscle generates will change throughout the movement (Force is greater at full contraction/shortening of the muscle). Unlike isometric exercises, this type of contraction does help build strength.
3. The Specificity of Training Principle: This refers to the fact that only the muscle or muscle group you exercise will respond to the demands placed upon it. By regularly doing bicep curls, for example, the muscles involved (biceps) will become larger and stronger, but curls will have no effect on the muscles that are not being trained (such as your legs). Therefore, when strength training, it is important to strengthen all of the major muscle groups.
4. The Detraining Principle: After consistent strength training stops, you will eventually lose the strength that you built up. Without overload or maintenance, muscles will weaken in two weeks or less! This is the basis behind why individuals lose muscle mass as they age—because they are detraining by exercising less frequently.
How Much Strength Training Should You Do?
When considering the guidelines for aerobic exercise, keep the FITT principles in mind (Frequency, (Intensity, Time and Type).
Frequency: Number of strength training sessions per week Aim to train each muscle group at least two times per week, and up to three if you have the time or are more advanced. One day per week may help you maintain your current level of strength, but in most cases, it will not be enough to build muscle. It is important to rest 1-2 days in between working the same muscle(s) again. Rest days give the muscles time to repair themselves from small tears that occur during strength training, and this is how you get stronger. For example, if you do a full body routine on Monday, do not lift again until Wednesday or Thursday (1-2 days). If you decide to split up your strength training (due to time, schedule or personal preference), and do upper body exercises on Monday and lower body exercises on Tuesday, it’s okay to lift two days in a row—because you are working different muscles. You wouldn’t lift upper body again until Wednesday or Thursday, or lower body again until Thursday or Friday.
Intensity: How much weight or resistance you should lift This is a tricky one—and if you’re new to exercise, it will take some trial and error. The intensity of the resistance you lift should challenge you. It should be high enough that as you approach your last repetition, you feel muscle exhaustion. Exhaustion means your muscle is so tired that you can’t do another full repetition in good form. Many people do not lift to exhaustion, mostly because they don’t know that they are supposed to. They tend to just lift the number of reps that they have subscribed to and stop.
For example, if you are going to do 10 reps of biceps curls, don’t merely stop on that 10th rep if you haven’t reached muscle exhaustion. You could either continue doing reps until you do reach exhaustion, or take this as a sign that the weight you are lifting is too light. Increase your weight until you do feel exhausted on the 10th rep. How much weight/resistance you lift will work hand in hand with the number of reps you do (see Time below).
Time: Number of reps and sets you should do Going from the starting position, through the action and back to the starting position counts as one rep. Most people lift somewhere between 8 and 15 reps, which equals one set. Most people do 1-3 sets with rest in between each set.
How many reps should you do? Most experts recommend between 8 and 15 reps per set. If your goal is to build strength and muscle size, then aim for fewer reps (like 8-10). Because you are doing fewer reps, you will need a heavier weight to reach muscle exhaustion in each set, so that’s where the words “heavy weight, low reps” come from. If your goal is general fitness or endurance, then aim for more reps (like 10-15). Because you are doing so many, you’ll need a lighter weight.
No matter what your goal, be sure to lift resistance that is heavy enough to exhaust you at the end of your set. So, while you may be able to curl 20 pounds and feel exhaustion in 8 reps, you may only be able to lift 12 or 15 pounds if you are doing 15 reps.
The ideal number of sets has been debated about for years. A good rule of thumb is 1-3 sets. Research studies have shown that performing 2 sets is not significantly better than one. And performing 3 sets is not significantly better than doing 2. The only significant difference is between 1 and 3 sets. As long as you are working to the point of exhaustion, you can maintain and even build strength by doing only 1 set. But unless you are crunched for time, most beginners start with 2 sets of each exercise.
Make sure you rest 30-90 seconds between sets. You can use this time to stretch the muscle you are working and catch your breath or get a drink of water. The longer you rest, the more strength you will have to finish out your next set just as strongly as the previous one—which will aid in your strength development.
Type: Activities that count as strength training Perform exercises to target every major muscle group when strength training: your arms (biceps and triceps), shoulders, chest, back, core (abs, obliques and lower back), and legs (quads, hamstrings, glutes and calves). Make sure you work opposing muscles, not just the ones you see when you look in the mirror (biceps, chest, abs, quads). The opposing muscles are the ones that work in opposition to those (in this case, the triceps, back, lower back, and hamstrings). Also be sure to work the sides of your body: obliques, hips, abductors and adductors (outer and inner thigh). The idea is to achieve balance. The same goes for the upper and lower body. Don’t neglect one or the other just because one is more important to you. This can create imbalance and set you up for injury and pain.
Strength training can be done with a variety of equipment such as resistance bands, stability ball, hand weights, machines, or body weight. The Fitness Resource Center has numerous examples of exercises and workouts for you to choose from.
Get the Most Out of Your Strength Training Workouts
These tips will help you get started on the right foot!
Check with your doctor before starting an exercise program. Get more about exercise safety tips for beginners.
Always warm up for at least 5-10 minutes before strength training.
Proper form is essential for safety and effectiveness. Start with light weights as you perfect your form and get accustomed to strength training. Gradually increase the amount of weight you lift over time, by no more than 10% each week.
Always cool down at least 5-10 minutes at the end of your workout.
Vary your exercise program to avoid boredom and plateaus. Changing your routine every 6-8 weeks is crucial to keeping your body/muscles surprised and constantly adapting. They'll have to work harder, you'll be challenged, and you'll burn more calories and build more lean muscle in the process. Learn how to change your exercise routine to avoid plateaus.
Drink plenty of water before, during and after exercise to stay hydrated.
Machines are best for beginners. They usually have detailed instructions and a picture on them, plus they show which muscles you are working. They are set up to put your body in proper form and isolate the right muscles. They are usually grouped together (upper body, chest, arms, legs, etc) in a weight room, so that you can easily move through them and target every major muscle group.
Free weights are more advanced. After you’ve had a good foundation with machines (or body weight exercises) you can move into free weights. When using free weights, form becomes even more important because there is nothing to support you or make you do it properly. Lift in front of a mirror and use the proper benches for support. Always watch the alignment of the joints and their relationships: shoulders, hips, knees, and ankles should be aligned. Your back should remain flat and your abs should be contracted to help support the lower back. Have a trainer assist you and have someone there to spot you if you are lifting heavy weights. Use tools such as the Exercise Demos to help you achieve proper form.
Don’t hold your breath, which can be dangerous (it increases blood pressure and can cause lightheadedness, for example). Exhale fully and forcefully on the exertion phase—usually the phase where you are lifting the weight. Inhale deeply on the easier phase—usually when returning to the starting position. Try to keep this rhythm throughout every set. In the beginning, it will take some concentration, but after a while, it will become habit.