This guide covers weight training in detail, at a level that should be accessible to new trainers and those with experience also. If you need even more basic information, try:
Definition. Weight training is organized exercise in which muscles of the body are forced to contract under resistance and tension using weights, bodyweight or other devices in order to stimulate growth, strength, power, or endurance. Weight training can also called ‘resistance training’ or ‘strength training,’ although these terms can have a more specific definition.
The basis of weight training success is a combination of factors based on the acronym FITT.
- Frequency of training - how often you train
- Intensity of training - how hard you train
- Time spent - elapsed time of a workout session
- Type of exercise - the type of exercises in your workout
Types of Muscle Contractions and Joint Movements
You should understand these basic movement definitions in order to follow more advanced training program instructions.
Isometric contractions: the muscle does not lengthen. An example of this is pushing against a wall.
Isotonic contractions: the muscle shortens and lengthens. The shortening phase is called a 'concentric' contraction and the lengthening phase is the 'eccentric' contraction. An example is a dumbbell arm curl where the muscle shortens as you raise the dumbbell by bending at the elbow (concentric) and lengthens as you lower it (eccentric). Slow eccentric contractions can increase post-workout muscle soreness (and perhaps accelerate muscle growth).
Joint movements. Muscle contractions relate to joint movements. Four important joint movements are flexion and extension, abduction and adduction. Flexion decreases the angle in the joint. An example is bending at the elbow in an arm curl which decreases the angle in the elbow joint. Extension is the opposite movement, that is, increasing the angle while straightening the arm and lowering the weight.
Abduction is moving a body part away from the middle of the body in the side plane. For the hip joint, an example is raising the legs out to the side of the body. Adduction is bringing them back again.
The main human muscle groups of weight training interest are the arms, shoulders, chest, back, legs, buttocks and abdomen. You can target all major muscle groups at a session with a range of compound (many muscle groups) and isolation exercises (single muscle group) or you can split it up into separate sessions for targeted body parts. Bodybuilders tend to utilize isolation exercises to define specific muscle groups. Sports and competition weight trainers tend to concentrate on compound exercises.
Strength, size and endurance of muscle is built by the overload principle. This entails lifting increasingly heavy weights or increasing the volume of work over time.
Strength, as distinguished from increased muscle size (called hypertrophy), is built by training the neuromuscular system and the interaction between the nerves and muscle, rather than muscle anatomy, the size and constitution of muscle fibers. Heavier weights with fewer repetitions and longer rest are employed to prioritize strength.
As a general rule, larger muscles will make you stronger, but probably not stronger than someone who trains for strength, all else being equal.
Strength training can involve loads in the range 3-6RM with higher loads of 1-3RM for more experienced lifters and a variable number of sets according to the program.
Hypertrophy training usually emphasizes more repetitions with lighter weight than strength training, often with shorter rest intervals between sets. This training enhances metabolic factors that result in muscle size increases.
You can get stronger training for hypertrophy, but your goals should be quite clear if you are interested in competition for bodybuilding or powerlifting, or explosive strength and power for sports. If you want a combination of strength and hypertrophy then you need to identify a weight training program that will provide a compromise, which is what most non-competition weight trainers are looking for.
One way muscle gets bigger is by a process of damage and repair at the micro level. Small tears, sometimes called micro-trauma, occur in muscle fibers under load and are repaired and rebuilt stronger when the muscle (and you) recovers. It’s a little like one step back and two steps forward at the cellular level.
There exists some disagreement over whether muscles get bigger by increased muscle fiber (cell) size or by splitting off and creating new cells. At the least, hypertrophy results from an increase in the contractile units called myofibrils and also from increased fluid in the cell called the sarcoplasm.
Hypertrophy training usually employs repetitions of 8-12RM with a variable number of sets but often in the range 2-5.
Building Muscle Endurance
Muscle endurance is trained at the higher end of the repetition spectrum. For example, doing 15-30 repetitions for 3 sets targets local muscle endurance rather than strength or hypertrophy. Doing this sort of muscle endurance training will provide some strength and hypertrophy compared to no training, and it can result in larger increases in aerobic conditioning than higher-intensity programs. There's no reason why you could not do 100 reps with a light weight but you would have to consider whether specific activity training like running, rowing, swimming or biking would not be more productive.
Power is the rate at which work is done; so power involves time. If you can lift the same weight faster than your friend then you have more power. Training for power involves increasing the speed of the lifts. The concept of power is useful in weight training for sports such as football where strength, bulk and speed are desirable.
Power training involves building strength first, then progressing to lighter loads performed at very fast or even explosive contraction velocity. Loads as light as 30-60% 1RM with rests of 2-3 minutes between sets are recommended by the American College of Sports Medicine.
Weight training, strength training or resistance training, builds the foundation for strength, power, bulk and muscle endurance for the following activities and sports.
- Bodybuilding, which specializes in body shaping and muscular definition, particularly for competition purposes. Hypertrophy programs predominate here.
- Sports-specific programs utilize exercises that support and enhance, as far as possible, the muscular actions of the sport. An example might be training swimmers to increase the strength of the pull through the water, by targeting shoulders, arms and back muscles. Strength-endurance and bulk and power programs are useful yet highly variable for particular sports and need to be designed so that they do not interfere with the skill set required for the sport. For example, you don't want to enhance bulk and strength at the expense of the speed and agility of a quarterback.
- Weight loss and fitness includes exercises that provide an all-round exercise program for adding muscle and losing body fat. Bodyshapers looking for the great beach body are included in this category.
- Olympic weightlifting is a specialty weightlifting sport that utilizes only two exercises, the clean and jerk, and the snatch, although there are assisting training exercises. Each lift is highly specialized and technical, requiring much training and practice.
- Powerlifting competition requires only three lifts -- the squat, bench press and deadlift. Again, strength and technique programs are the basis of Powerlifting.
Training Frequency and Overtraining
How often and how much you train depends on your goals, experience, age, health, fitness and other factors such as equipment accessibility and time available for training. A trainer or coach should take all of these factors into consideration when designing a plan that suits your circumstances and goals.
The fine balance in weight training is the balance between muscle and nervous system stimulation, adaptation and recovery. Too much intensity, volume and frequency too quickly, and overtraining syndrome can destroy your progress. Here are some signs of overtraining in men and women:
- Ongoing fatigue, poor performance
- Viral and bacterial infections
- Unintended loss of weight
- Regular musculoskeletal injury
- Cessation or irregularity of periods
- Hormonal imbalances
- Bone density loss
- Poor sleeping and eating patterns
Training three times per week is a sweet spot for optimum progression for beginners, although twice per seven-day week will suit some people better. A usual recommendation for novices is to allow at least 48 hours between weight sessions to allow for recovery. For experienced and professional trainers, six days a week training is not unusual, although split systems – training different muscle groups on different days – is often practiced. If you feel you're getting into trouble, back off and get some good advice.
Types of Exercises
Many hundreds of exercises exist to target many muscles and muscle groups and it can get more than a little confusing for the average beginner to choose. Exercise variations come with free weights, machines, racks and frames, body-only exercises, bands, balls and more.
Compound exercises. Compound exercises are those that involve more than one joint, and often several large muscle groups. Examples: squat, deadlift, seated cable row, lat pulldown.
Isolation exercises. An isolation exercise is one involving only one joint and which usually targets an isolated muscle group. Examples are the dumbbell arm curl for biceps and the leg extension machine for quadriceps.
Which Exercises Should I Do?
It’s not avoiding the question to say that it depends on your goals, the equipment and facilities you have available, your age, fitness, weights experience and commitment.
There is general agreement that the ‘big three’ lifts -- the powerlifting lifts -- squat, bench press and deadlift -- are the core lifts for building bulk and strength. They are technical, and perhaps even dangerous, done with free weights near the limit of your maximum, so guidance and a spotter are useful if not essential. Even so, the first rule is to start 'light' and build your strength and experience progressively so that early mistakes don't mean disaster.
If you’re training for a good balance of body composition and strength you could add additional back, abdomen and shoulder exercises and more specific work on the front of the arms. Consider the basic strength and muscle program. This includes squat, bench press, deadlift, arm curl, triceps pushdown, lat pulldown, seated cable row, crunch, overhead press and leg press.
Many more isolation and compound exercises are available for variety and specificity.
For the more experienced, total-body exercises like cleans, hang-cleans, power cleans, push-press, and thrusters would benefit.
In bodybuilding, where muscle definition of even the smaller muscles can be important, a wider range of isolation exercises is usually practiced.
A repetition (rep) is one completion of an exercise: one chin-up, one squat, one arm curl. A set is the selected number of repetitions before you rest -- for example, 10 repetitions to 1 set of arm curls. The rest interval is the time between sets. The 1RM or repetition maximum is your personal best or the most you can lift once in any exercise. So 12RM is the most you can lift for 12 repetitions. So if you see:
Barbell Arm Curl, 40 pounds 3 X 12 RM, 60 seconds
That would mean 3 sets of 12 maximum arm curls with a weight of 40 pounds with 60 seconds rest between sets. So how do you know how many reps, sets and rest time is best for you? Here’s how it works in broad terms. The finer details are for you and your trainer to work on.
- Strength training uses the most weight, least number of repetitions and longest rest.
- Hypertrophy or muscle size training utilizes lighter weights, more repetitions and less rest time.
- Strength endurance utilizes less weight again, with more repetitions and even less rest.
- Power training involves lighter weights and longer rests while concentrating on the speed of the lift.
These are general principles, and you can try various combinations of sets, reps, rest and exercise type to find the best combination for you.
Here’s how an exercise program for the bench press might look according to different goals starting from a theoretical personal best of 160 pounds (73 kilos):
Bench Press - 1RM = 160 pounds
- Strength. 140 pounds, 2 X 5, 180 seconds
- Hypertrophy. 120 pounds, 3 X 10, 60 seconds
- Strength Endurance. 80 pounds, 3 X 20, 45 seconds
- Power. 100 pounds, 3 X 8, 120 seconds
One point to note here is that it is mandatory to take adequate rest between heavy loaded sets in strength training in order to achieve best results. In power training, a sufficient rest interval is also important because each lift has to be done at high explosive velocity for best effect. So in strength and power training, make sure you get the required rest in between sets. In hypertrophy and strength endurance it’s not as crucial to use shorter rest intervals, although perhaps optimum.
Speed of Exercise Execution
Contraction velocity is the speed at which an exercise is performed and this also has an effect on training outcomes. Here are general guidelines for weight training goals.
- Strength -- 1-2 seconds concentric and eccentric
- Hypertrophy -- 2-5 seconds concentric and eccentric
- Endurance -- 1-2 seconds concentric and eccentric
- Power -- less than 1 second concentric, 1-2 seconds eccentric
According to the US National Strength and Conditioning Association, the theoretical distribution of repetitions against a percentage of 1RM, your maximum lift, is distributed as follows, using the bench press example:
- 100 % of 1RM -- 160 pounds -- 1 repetition
- 85% of 1RM -- 136 pounds -- 6 repetitions
- 67% of 1RM -- 107 pounds -- 12 repetitions
- 65% of 1RM -- 104 pounds -- 15 repetitions
- 60% of 1RM -- 96 pounds -- warmup reps
(Based on: Baechle and Earle, NSCA’s Essentials of Personal Training, 371, 2004.)
This means that you should be able to do 1 lift at your personal best, 6 lifts at 85 percent of your personal best and 15 lifts at 65 percent of your 1RM personal best – and with proportional percentages for any lift in between, and probably below.
Don’t consider this an absolute reference; it’s only a guide and a basis from which to choose appropriate weights for working out. You can see how you can estimate your personal best or 1RM from your 12 RM -- multiply 107 by 100 divided by 67.
A training ‘program’, is a schedule of frequency, intensity, volume, and type of exercise, whether for weight training or any other fitness training. In weight training, various methods and techniques are used.
Here are the variables that can be adjusted in any weight training program. Almost unlimited combinations are possible, most of which will be functional at some level but not necessarily optimum.
- Exercise selection
- Weight or resistance
- Number of repetitions
- Number of sets
- Velocity of movement
- Interval between sets
- Interval between sessions (training days/week)
- Interval between periodization cycles
Here are some prominent applications and techniques in weight training and bodybuilding programming.
- Full body training. Training all major muscle groups in a session. You choose a series of lifts, perhaps up to ten, ensuring that all major muscle groups are exercised at some level
- Split system. Alternating sessions for major muscle groups. Training, say, arms, shoulders and back one session, then legs buttocks, abdominals the next session.
- Periodization could be described as progressing or cycling phases of training over a set time in order to achieve results at a scheduled time. Dividing a yearly program into different training phases with different sequential goals is an example. This is common in sport-specific programs and in competition forms of weightlifting. For example: off-season maintenance, pre-season strength, early season hypertrophy and power, active season maintenance, post-season recovery.
- Supersets. Supersetting is the practice of exercising two opposing muscle groups in quick succession for the purpose of stimulating muscle growth and providing rest in either group alternately. Leg extension and leg curl for quadriceps and hamstrings is an example.
- Compound sets. Rather than alternate different muscle groups, compound sets alternates different exercises or equipment for the same muscle group. An example is following the triceps kickback with triceps pushdown -- the idea being to push the muscle far enough so that it recruits additional motor units, perhaps with the aid of alternate, assisting muscles.
- Pyramid. This type of program includes sets that progress from lighter to heavy weights of the same exercise, or even the reverse from heavy to light depending on the program. The number of sets is specified. For example, dumbbell curl:
-- 20 pounds X 10 repetitions
-- 30 pounds X 8 repetitions
-- 40 pounds X 6 repetitions
- Drop sets are like a reverse pyramid and there are many variations. In one example you lift to failure regardless of the number of reps in the second and third sets. Start with a heavy weight and do a calculated number of repetitions; reduce the weight by, say 20 percent, perform the next set to failure; then reduce again and go to failure again with little interval rest. This is very high intensity training. An example is the dumbbell curl as follows:
-- 40 pounds X 8 repetitions
-- 30 pounds X failure
-- 20 pounds X failure
- Superslow. Superslow encompasses the idea of slow and measured concentric and eccentric contractions. The proposed advantages of this are disputed by many. Superslow enthusiasts recommend more or less 10 seconds for each phase of the lift.
- Eccentric training. This emphasizes the return or muscle lengthening action of any lift on the basis that this produces better hypertrophy because more muscle damage and fiber recruitment is achieved. Arm curls are a good example.
- Sport specific programs are designed to enhance performance in particular sports by strengthening muscle fitness specific to those sports, especially through periodized weight training.
Diet, Nutrition and Supplements
Appropriate diet and nutrition are very important in maximizing results from any athletic training program, and weight training is certainly no exception. Read the article: The Weight Trainer's Bodybuilding Diet for detailed information. Subscribe to the About.com Weight Training newsletter for regular updates.
Med Sci Sports Exerc. 2009 Mar;41(3):687-708. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. American College of Sports Medicine.