What is "Tightercise" or tightening?

Tightercise is a type of exercise that mimics the instinctive stretching you do every morning when you wake up. Stretching in the morning is a tool your body uses to mobilize stored energy to help get your day off to a great start. Feels great too! It also helps build muscles that need strengthening, which explains why you sometimes contort your body into strange positions to get the right stretch. You can use Tightercise to direct your body to strengthen and grow certain muscles. Tightercise involves first shortening or balling up a muscle (i.e. for your bicep, you bend your arm till your hand reaches your shoulder) and then clenching that muscle as hard as you can for a period of 2-5 seconds, or until the muscle starts to hurt a little or feels like it’s starting to cramp. You can do this with any muscle or muscle group that you want to build, usually a few minutes before or after eating. This communicates to the body that you need these muscles in order to survive, so the body will prioritize building them quickly and efficiently.