The word hypertrophy simply means;
“The enlargement of an organ or tissue from the increase in size of its cells”
So, in terms of hypertrophy training, the main focus is to increase and build muscle mass. Although strength gains will be a bi-product of hypertrophy training, this type of training isn’t solely geared towards hitting new strength goals. There are many other factors that contribute to the increase in muscle mass, such as signalling pathways in the muscle, hormones, and oxygen and nitric oxide levels. This article will focus purely on the training needed to induce muscle hypertrophy.
The main factors in hypertrophy training are:
Mechanical Tension – This is purely the movement in which you are lifting a weight. Instead of just feeling the weight and doing anything you can to lift it up then back down, really focus on the movement and practice correct form. Research has found that taking more time on the eccentric part of the movement has found to induce more muscle hypertrophy. For example, when executing a bicep curl, the part of the exercise where the bicep is brought up to the shoulder should be fairly explosive (1-3 seconds), this is the concentric movement. And the part of the exercise which brings the arm back down is known as the eccentric movement, this should be 2-4 seconds.
Muscle Damage – This means that we are putting our muscle fibres under enough stress in order to ‘tear’. The fibres need to undergo enough damage to repair in order to grow. It’s no good continuously doing 16 reps of a weight that isn’t causing damage to the muscle. Our bodies are smart, if we don’t give the body a reason to gain more muscle, it simply won’t.
Metabolic Stress – Although not as important as the above two, metabolic stress still plays a secondary role in muscle hypertrophy. The metabolic stress that resistance and weight training causes manifests itself in the accumulation of metabolites. Metabolites are the bi-products of nutrient breakdown and provide the body with the type of fuel used during resistance training that causes the hypertrophic response.
Training Intensity – The intensity at which you train seems to have one of the most important roles for stimulating muscle growth. High rep ranges (15+) have been found to be inferior in increasing muscle hypertrophy and anything below 65% of your 1 rep max is not considered sufficient to promote substantial muscle growth. It’s been found that a rep range between 6-12 reps has shown the most significant increase in hypertrophic response.
Volume – Volume means the amount of reps, sets and the load performed in a training session. It’s been found that more volume positively correlates to increased muscle hypertrophy. This means more reps and sets. So instead of lifting 90% of your 1 rep max for 5 reps then resting for say 3 minutes, lifting 75% of your 1 rep max for 10 reps and resting for 2 has been shown to increase muscle hypertrophy more than the first mode of training. The volume should be increased over time in order for hypertrophy to be maximised, this means adding a few more reps, sets or increasing load. This can be done by incorporating super-sets and drop sets into your regime.
So, as an example, a typical hypertrophy training workout could consist of 5 exercises on whatever body part you are training (let’s say chest as an example). Each exercise is performed to 75% of your one rep max for 3 sets of 10 reps, remember to focus on the movement of each exercise really feeling the muscle do the work and making sure the eccentric part of the exercise is slower than the concentric. After a few sessions, your body will adapt to the weight and the volume so in order to continuously grow muscle there must be change. You could then either slightly higher the repetitions (12 reps per set) or add on another set completely. You can then look to increase the load. To really tax the muscle, you could incorporate 2 exercises at the same time, this is known as a super-set.
Hopefully this article has given you a bit more insight into the mechanisms of building muscle and what type of training is required to do so.