If you are one of the people who has avoided strength training because of a fear of getting too muscly or bulky, read on and learn why this may not happen to you, and ways you can reduce the odds that you will get bulky.
- Lift quickly - one of the biggest contributors to building bulky muscle is something called time under tension (TUT). In short, the main theory is that the longer the TUT, the greater the hypertrophy, or muscle growth. In part, this happens because moving weights slowly increases the engagement of slow twitch fibres, and the increase in cross-sectional area (CSA) of these fibres adds to bulk. To avoid this, reduce the TUT by learning to move quickly. This approach increases the engagement of fast twitch muscle fibres, which have less of a propensity to increase in CSA. A quick point has to be made here though - an increase in muscle CSA is actually required to increase strength. In fact, one of the first things that has to happen for strength to develop is for muscle CSA to increase. The increase in CSA changes the angle of the muscle fibres relative to connective tissue, and this change helps to produce the forces required to lift heavier weights. But putting all that aside, lift quickly and you'll reduce the chances of getting too bulky.
- Avoid excess calories - to build additional muscle requires surplus calories, particularly increased protein. If your goal is to increase strength, but not size, simply maintain a relative caloric balance, and the body will have a limited capacity to build additional muscle. It is important to ensure that sufficient calories are being consumed to meet daily requirements, or if fat loss is desired, reduce carbohydrate and fat intake but maintain protein intake.
- Train in endurance sports - there are two key signaling pathways that are activated in response to training stimuli - one pathway, known as the mammalian target of rapamycin (mTOR), promotes muscle protein synthesis that ultimately increases muscle mass; the other, known as the adenosine monophosphate kinase (AMPK) pathway promotes the production of new energy production organelles (known as mitochondrion, produced in a process called mitochondrial biogenesis). When the AMPK signal is stronger than the mTOR signal, the body preferentially builds mitochondria, and down-regulates muscle protein synthesis. To up-regulate AMPK signaling, you simply need to engage in regular, moderate to high intensity aerobic training at a greater volume than any strength training. A word of warning here - the up-regulation of the AMPK pathway will ultimately limit how strong you can get, mainly due to the down-regulation of the mTOR pathway and corresponding reduction in muscle protein synthesis, so if strength is your key goal, be judicious with the use of aerobic training.
- Have the right kind of genotype - some people don't build muscle easily, some people do. If you're the former, you may not have much of a say in how muscly you get. Sorry. All you can do there is accept that you build muscle, use the other three strategies listed above, and recognise that there will be a pile of people who will be jealous about how easily you build muscle...
Strength training is incredibly beneficial for all people, irrespective of age, gender, lifestyle or performance goals. The fear of building bulky muscle can stop many people from engaging in an otherwise very healthy activity. If this fear has stopped you, you now have the tools to go forward and get stronger, without getting too big.