By Myprotein Writer
Max Wilson M.S.c
Muscular hypertrophy is the one of the most common goals of those who weight train. In fact building muscle is arguably one of the most important consequences of weight training ,as its effects have wide spread ramifications in the fields of bodybuilding, physique contests, also given the close relationship between muscle size and strength (Kraemer and Ratamess, 2004), sports performance.
Whilst most weight training programs will result in some muscle growth, however information regarding how to maximise hypertrophy is conflicting. The principle of specificity suggests that some kinds of weight training will result in more hypertrophy than others (Schoenfeld, 2010). Research has found that with careful manipulation of the principles of training hypertrophy can be optimised (Kraemer and Ratamess, 2004).
Research has suggested that intensity is the most important training principle for the stimulation of hypertrophy (Fry, 2004). Intensity is the amount of weight lifted, generally defined as a percentage of the maximum amount of weight a person is able to lift.
Intensity and volume have an inverse relationship, therefore as the weight lifted increases the amount of reps possible decrease. Typically, rep ranges fall into one of three groups, High (15+ Endurance), moderate (6-12 Hypertrophy) and low (1-6 Strength), with each rep range having a maximum weight that can be lift for said number.
Research has found that each of these rep ranges are fuelled by different energy systems resulting in fatigue occurring at different rates, therefore stimulating a different anabolic response (Schoenfeld, 2010).
Studies have identified that using a moderate rep range stimulated a greater hypertrophic response (Kraemer and Ratamess, 2004) as it primarily uses anaerobic glycolysis to produce energy (Robergs et al., 2003), this results in an accumulation of waste products that stimulates an anabolic response.
Additionally, the higher loads associated with training using a moderate rep range may stimulate the mechanisms that result in hypertrophy through increased mechanical tension and muscle damage, resulting in a three pronged hypertrophic response.
This can be considered as the number of reps contained in a set or as the total amount of work performed (Schoenfeld, 2010).
Research has repeatedly shown that training consisting of a number of sets produces greater muscle growth than training consisting of single sets (kraemer and Ratamess, 2004).
This is suggested to result from increased testosterone and growth hormone secretion that occurs during multiset training (Kraemer et al., 1991).
Hypertrophy | Rest periods
Rest periods, like rep ranges, can be divided into long, moderate and short, and again like rep ranges each rest period has a different impact on hypertrophy (Wilardson, 2006).
Research has found that moderate rest periods (60-90s) produce a greater hypertrophic response when compared to short and long rest periods (Kraemer and Ratamess, 2004). This may be because this time duration allows for an accumulation of metabolic waste products which increase anabolic hormone secretion whilst allowing for the regeneration of muscular strength, which increases hypertrophy due to mechanical tension (Ratamess et al., 2007).
While it is beneficial to have sufficient rest between sets it is commonly believed that in order for maximal hypertrophy to occur muscular failure should occur. Muscular failure is the point at which a muscle can no longer produce the force needed to complete any more reps with a given load (Scheonfeld, 2010).
Although, research is conflicting on the actual benefits of training to muscular failure, it is thought that by taking a set to failure more motor units are recruited resulting in a greater hypertrophic response (Wilardson, 2007). Additionally, at muscular failure, it has been found that there is a greater accumulation of metabolites heightening metabolic stress resulting in a greater production of anabolic hormones (Linnemo et al., 2005).
It is worth remembering that training to failure increases the risk of over-training and subsequent muscle loss, therefore it is vital that training to muscular failure is done as part of a periodised training program.
Research has shown that a training plan consisting of both compound and single joint movements result in muscle growth than training with either compound of single joint exercises alone (Schoenfeld, 2010).
This may be because compound exercises utilise a greater number of muscles, resulting in an increased hypertrophic response. Kraemer et al. (1992) reported increased growth hormone levels post training, following compound exercises than using single joint movements alone.
However, single joint exercises provide a greater emphasis on the individual muscle being trained, allowing for differing neuromuscular activity, resulting in increased muscle growth.
✓ Muscle growth is stimulated by mechanical tension, muscle damage and metabolic stress.
✓ Use heavy weights (70-80 1RM).
✓ Utilise a moderate rep range (6-12) over multiple sets.
✓ Train using both compound and single joint exercises.
✓ Rest between each set for 60-90 seconds.
✓ Periodise training to avoid over-training.
✓ Consult a doctor before begin any new training program.
Take home message
Whilst hypertrophy is the overall goal of most people who weight train, information regarding training methods to produce optimal muscle growth is conflicting.
Research has identified that weight training stimulates muscle growth through mechanical tension, muscle damage and metabolic stress.
Therefore with careful manipulation of training principles it is possible to stimulate all three hypertrophic mechanisms to optimise muscle growth.