This guide covers weight training in detail, although at a level that should be accessible to new trainers and those with some experience as well. If you need more elementary information, try:
- Weight Training Primer - Before You Start
- Begin That First Weights Session (Gear etc)
- Where to Weight Train: Home or Gym
Definition. Weight training is organized exercise in which muscles of the body are forced to contract under tension using weights, bodyweight or other devices in order to stimulate growth, strength, power and endurance. Weight training is also called ‘resistance training’ and ‘strength training’.
The basis of weight training success is a combination of factors sometimes called FITT.
- Frequency of training - how often
- Intensity of training - how hard
- Time spent - session time
- Type of exercise - which exercises
Types of Muscle Contractions and Joint Movements
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 (concentric) and lengthens as you lower it (eccentric). Eccentric contractions are mainly what give you sore muscles.
Joint movements. Muscle contractions relate to joint movements. Four important joint movements are flexion and extension, abduction and adduction. Flexion is when you decrease the angle in the joint. An example is the upward movement of an arm curl which decreases the angle in the elbow joint. Extension is the opposite movement, that is, increasing the angle while lowering the weight.
Abduction is moving a body part away from the middle of the body in the side plane. An example is raising the legs out to the side of the body. Adduction is bringing them back again.
The main muscle groups of interest that make up the human body are the abdominals, adductors (inside thigh), dorsal muscles (middle back), shoulders, arm extensors, wrist extensors, gluteals (butt), arm flexors, wrist flexors, scapular fixers (shoulder blade), thigh flexors (hamstrings), lumbar muscles (lower back), surae (calves), pectorals (chest), quadriceps (front thigh) and trapezii (upper back).
Looking at it in less detail, the major muscle groups are the arms, shoulders, chest, back, legs, buttocks and abdomen. You can target all major muscle groups at a session with a range of exercises or you can split it up into separate sessions, or you can just do competition lifts and assists which tend to target the large muscle groups.
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 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 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. If you just 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 trainer recovers. It’s a bit 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 as well. 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 15-20 repetitions per set targets local muscle endurance rather than strength or hypertrophy. Again, doing this sort of muscle endurance training will provide some strength and hypertrophy compared to not training, and it can result in larger increases in aerobic conditioning than higher-intensity programs.
Muscle endurance training can use repetitions in the range 15-20 with a variable number of sets, but 3 is common. However, you have to ask yourself if training in a skill activity like running or swimming or biking is not more productive use of your time.
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 light 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.