Muscle Burn and Muscle Soreness

You know when you’re pushing the prowler, and you feel like your quads might spontaneously combust? The burn is almost unbearable, and then shortly after you stop, it disappears. Ever wondered what causes that?

Muscular System Abdominal WallHere’s a short explanation:

  • When you train at a high intensity, you need a lot of  ATPquickly. Your body’s pretty smart, so it produces ATP anaerobically (without oxygen), because it’s faster and requires fewer steps.
  • Energy for high intensity training comes primarily from glycolysis. In a nutshell, this means glucose is breaks down and oxidizes to form pyruvate. But when oxygen is limited, the body temporarily converts pyruvate into a substance called lactate (commonly referred to as lactic acid). This allows glucose to breakdown, so you can still produce energy. But during some high intensity activities, lactate is produced faster than your body can process it. This causes lactate concentrations to rise. Oh yeah, feel the burn!
  • Once you stop lifting weights, sprinting, or pushing the prowler, oxygen becomes available and lactate reverts back to pyruvate, so no more lactate. And no more burn.

Click here for a more detailed explanation.

So does lactate cause muscle soreness, too?

No, it doesn’t. Although it’s often blamed for Delayed Onset Muscle Soreness, it’s not the cause. DOMS, which usually occurs between 24-72 hours post-workout, is believed to be caused by micro-trauma the muscle cells.  It most frequently occurs as a result of eccentric loading (the muscle lengthening under a load). 

So when you start a new program, or when you work at a much higher intensity than normal, you might experience DOMS. That’s never the goal, but sometimes it’s unavoidable. AND it’s completely unrelated to the burn you experienced during the workout!

Click here to learn more about DOMS.