All of you regularly participate in weight training at our facility somewhere between 1-4x / week, but are you aware of the changes happening in your body while you lift? There are three primary muscular changes that occur after resistance training: Increased muscle size (hypertrophy), muscle fiber transition (I’ll explain), and enhanced muscular structure. Each of these changes leads to an increased ability to produce force, power, and endurance.
Muscle hypertrophy is the growth in size of a specific muscle group (i.e. your biceps). When you do a set of biceps curls, the tiny little muscle fibers inside the bicep undergo stress and cause damage. Don’t worry, this is a good thing as this damage signals all sorts of hormones (testosterone, growth hormone, cortisol etc.) that help rebuild the muscle tissue. As this is done repeatedly, the body begins to synthesize more proteins, called actin and myosin, that contribute to an enlarged muscle, and therefore a bigger bicep! It can take anywhere from 6-20 weeks to see the size gains though, depending on how long you have CONSISTENTLY been training your muscle.
There are three main types of muscle fibers: Type 1 (slow oxidative/aerobic), Type 2a (fast twitch- glycolytic), and Type 2x (fast twitch- alactic). Each of these three fibers are found in every single muscle, but their distribution will vary based on what the muscle is used for, genetics, and what type of resistance training you may be participating in. Muscle fibers can transition from one type to another based on training stimuli. For example, if you are a marathon runner, you will likely have a higher distribution of type 1 fibers because you need them for long durations of activity. If you were to add strength training, you could transition some of those fibers to type 2a fibers which would give you the ability to produce more force into the ground as well as change speeds at a greater degree than you would have previously.
I will touch briefly on muscular structure as it can be a bit much to digest in an email. When you undergo resistance training, you can change the structure of a muscle. As I mentioned above, within each muscle there are tiny microscopic fibers that house all of the “ingredients” necessary to grow and build stronger muscles. When you do a lot of bicep curls for several weeks, your body will adapt to the stress by adding more size (see hypertrophy above). With that increased size you also increase the ability to contract your muscle stronger, fire your muscle at a greater rate, rebuild the muscle fibers quicker, and buffer your hormones at a higher rate.
It is no wonder why weight training is such an important addition in your routine for your overall health. Take care of yourself now, so that future you can be strong and healthy for the long run!
Nick and Tom
