Bodybuilding/Muscle Building is the process of utilising specific nutrition and training techniques in order to strengthen and enlarge muscles. The increase in muscle size (muscle hypertrophy) occurs through an increase in the size of individual muscle cells. Muscular hypertrophy occurs from a number of factors;
1) An increase in the volume of Sarcoplasm within a muscle fibre
2) An increase in the contractile proteins actin and myosin
3) An increase in the amount of capillaries per muscle fibre (Capillary density)
4) A possible increase in the total number of muscle fibres (hyperplasia)
Muscle hypertrophy is normally stimulated through specific strength/resistance training using free weights, resistance machines, resistance bands and bodyweight exercises. In order to maximize muscle hypertrophy following strength training it is important that the optimum intensity, volume and rest intervals are utilised.
Training Intensity/Training Load and Muscle Building
The training intensity relates to the percentage of 1 repetition maximum (1RM) – the amount of weight that can be lifted in one maximum effort. Typically muscle building routines involve training at between 65 and 90% of 1RM (Medium to High Intensity) which equates to around 4-15 repetitions. Recent research suggests that training at lower intensities may also be beneficial for muscle hypertrophy when performed to failure.
Training Volume and Muscle Building
The training volume relates to the amount of work performed during a workout – number of sets and repetitions. Training volume plays a key role in muscle hypertrophy with lower volumes required for untrained/inexperienced bodybuilders and higher volumes required for more experienced individuals.
Rest intervals between sets
Bodybuilding/muscle building programmes utilize shorter rest intervals (30-60 seconds) than training plans targeting strength development. Shorter rest intervals enhance the anabolic response to training, allow a greater volume to be completed in a set time period, and allow a greater average training intensity to be completed due to a greater work to rest ratio.