The Big Muscle Workout
How Your Muscles Grow
It would be easy to assume that you build muscle when you lift weights, but the truth is that weightlifting is only part of a much bigger process. In fact, your body only starts the biological work needed to pack on muscle once you put down the dumbbells. Here’s a breakdown of what happens after you hit the showers.
1. Each muscle fibre is made up of thousands of myofibrils containing tiny actin and myosin proteins. When you lift weights, the mechanical force on your muscles dam- ages these proteins and causes small microtears in the muscle membranes.
2. The damaged areas are then invaded by chemicals called “reactive oxygen species”. These act like mini car-bombs inside your fibres, causing further destruction to the muscle tissue.
3. All this disruption leads to an immune and inflammatory response. White blood cells and inflammatory agents are sent to the damaged sites.
4. These cells and chemicals remove the damaged parts of the fibres and replace them with new tissue.
5. Your body ramps up its production of actin and myosin to replace any proteins that were damaged. If you regularly lift weights, your body will adapt by building more of these contractile units. This increases muscle size.