Movement As Medicine

Working muscles are sugar-burning powerhouses. Heres how physical activity impacts your blood glucose, even hours after you stop sweating.

- Micaela Young, M.S.

Before Exercise

At rest, two hormones from your pancreas—insulin and glucagon— play opposing roles to keep your blood sugar stable: insulin moves sugar into your cells and glucagon shuttles sugar out of cells. After you eat, sugar and other nutrients are released into your blood from your intestines. Insulin levels rise to move that sugar into your cells, including muscle and liver cells, to be used or stored. Between meals, glucagon levels rise to maintain your blood sugar by releasing that stored glucose back into your bloodstream— preventing lows.

During Exercise

THE WARMUP

It’s time to get your heart pumping. As you start to move, your muscles use their own stored sugar as well as sugar from the bloodstream to make an energy compound (called ATP) that helps them contract. And soon, your hungry muscles need more sugar to make that fuel. So your body gradually lowers insulin levels and raises glucagon levels to release more stored sugar (from your liver) into your bloodstream for muscles to use.