Resistance Training Terminology

Repetitions:
Repetition (rep) is defined as 'one complete movement of an exercise'. It is a cycle of muscular contractions, which for most exercises will be one concentric and one eccentric muscle action.

Repetition Maximum (RM):
This is the maximum number of repetitions at a given resistance that can be performed in a set with proper technique. 1RM means the maximum weight that can be lifted ONCE (effectively maximal muscular strength). A 10-15RM target means that momentary voluntary fatigue should sit in between the tenth and fifteenth repetitions. RM is usually used as a guide for the load or weight.

Intensity:
Intensity refers to how much effort is applied to an exercise, not the amount of fatigue encountered or how hard an exercise feels (relative intensity). In the case of resistance training, 1RM would equate to maximum intensity. Intensity of an exercise can be estimated as a percentage of the 1 RM. Unlike cardiovascular exercise, intensity in resistance training does not correlate with heart rate.

Volume:
Training volume can mean the total number of repetitions performed in a training session or the total amount of weight lifted (load) in a session. But it can also refer to as the total amount of work performed in a session, a week, a month, or some other time period. There is a strong relationship between the volume of training and goals, such as hypertrophy (bodybuilding).

Compound and isolation exercise:
Compound exercises are defined as multi-joint exercises, or those that involve more than one joint. Isolation exercises on the other hand involve only one joint. For example, the squat is a compound exercise that involves the hip, knee and ankle joint; the leg extension only involves the knee joint and therefore, is an isolation exercise.

Compound exercises rely on good neuromuscular co-ordination between agonists (= muscles that contract to produce and control movement), antagonists (= muscles that relax whilst the agonist is contracting), synergists (= muscles that assist the agonist by modifying the desired movement) and fixators (= muscles that fix another part of the body, usually a nearby joint, so that it remains stable). As more muscle groups are utilized during compound work, more weight can be lifted and functional movements can be more efficiently trained. This is especially valid for sports specific training and rehabilitation, as long as the correct technique is adhered to.

Delayed Onset Muscular Soreness (DOMS):
Hard exercise can induce DOMS, usually occurring 24-72 hours post-training. This seems to be caused by exercise-induced muscle damage followed by some inflammatory response, although the exact mechanisms are still not fully understood. It does seem that eccentric muscle actions cause the most DOMS. Excessive post-training muscular soreness, lasting up to 7-11 days after resistance training, is a prime example of excessive stimulus being applied.

Hypertrophy:
'Muscle mass', 'muscle bulk', building up', bodybuilding' are just a few of the layman's terms used to describe muscle hypertrophy. Hypertrophy is simply referring to muscular enlargement and is brought on predominantly by an increase in cross sectional area of the muscle fibres. Moderate loads and high volume training with short to moderate rest periods are required in order to achieve hypertrophy.

Anabolism and Catabolism:
Anabolism refers to all the 'building up' reactions occurring within the body, such as laying down more contractile protein as an adaptation to resistance training.
Catabolism refers to the 'breaking down' reactions occurring within the body, such as the breakdown of triglycerides and glycogen during sustained endurance training.

Types of Resistance:
There are a number of methods that can be used in order to apply resistance for resistance training:

	Free-weights (Barbells, Dumbbells, Medicine Balls etc)
	Resistance machines (Fixed-path machines or cables)
	Body weight
	Manual resistance (applied by a partner or an opposing limb)
	Rubber bands / Dynabands
	Water (Hydrotherapy)

Each of these modes has a place with benefits and drawbacks to each.
Free weights are proprioceptively enriched, and encourage balanced training between agonist, synergists and fixators. However, learning techniques can be difficult, and beginners need to be constantly monitored and checked for technical faults.

Breathing:
Breathing patterns during exercise are sometimes over-emphasised to the detriment of good exercise technique. There is little need to instruct on breathing, as it should occur naturally. For many exercises you should exhale on exertion (on contraction of the muscle being trained); however, this is not always the case. In the example of a lateral pulldown, it can benefit the technique to breathe in, and lift the chest, during the exertion phase (pulling the bar down). Hyperventilation during resistance training can cause dizziness and should be avoided. For the most part, as long as you are not holding your breath, this can be left until the technique of the exercise is learnt.

In the case of breath holding during resistance exercise, there are some instances when this is advocated. Advanced weight lifters will use the Valsalva manoeuvre, which is an expiratory effort made against a closed glottis, for many exercises such as squats and deadlifts. This will increase their stability around the abdomen, thus protecting the back and increasing overall strength. Unfortunately, this will also increase blood pressure and decrease the volume of blood going to the brain, and returning to the heart. It is therefore, extremely dangerous for individuals who have chronic heart disease or high
blood pressure. Exercises and intensities requiring the use of the Valsalva manoeuvre should, therefore, not be advocated for these groups.