What Happens To Your Body When You Start Exercising Regularly | The Human Body

After you’ve done a few cardio workouts, the mitochondria in your cells proliferate.

“The mitochondria are the energy factories of the cell, which makes you fitter so you can produce energy more efficiently,” Professor Newton explains.

“It’s also beneficial for cell health – it makes them more resilient and helps them remain healthier for longer. There’s also increases in enzymes involved in producing energy for muscle contraction.”

After two to four weeks your nervous system is much more efficient at being able to contract your muscles,” Professor Newton explains.

“If you look at the muscle cells under a microscope, you see the slow and fast twitch muscle fibres are getting bigger. It means you are laying down more protein into your muscles, and you start to see your metabolic rate increasing so that even when you are asleep you are burning more energy.”

“In general it takes around six months of weight bearing exercise before you can see measurable changes in the skeleton,” Professor Newton says.

“Then you start to see increases in bone density and by 12 months, you see people who are osteoporotic return to normal bone health, and that’s massive in terms of reducing your risk of fracture.”

Your mental health will likely have also stabilised after one year.

“Very large systematic reviews indicate that appropriate exercise is more effective than cognitive behavioural therapy in reducing anxiety and equal to or better than pharmaceuticals for certain types of anxiety,” Professor Newton says.