Sweating intensifies
During HIIT, energy is generated that raises the body temperature. Blood vessels that are close to the surface dilate, increasing blood flow, blush appears, and sweating increases.
Muscles are stretched
During HIIT, small tears appear in the muscle fibers, and this is really beneficial because the muscles regenerate and become stronger. Leukocytes begin to regenerate damaged fibers in about 12-24 hours. They produce chemicals that cause muscle pain. The more intense workouts you do, the more accustomed your muscles become to stress. Ironically, the more you work out in the gym, the less pain you have.
Pulse quickens
The easiest way to know if you are doing your workout correctly is to monitor your heart rate. During high-intensity training, muscles require more oxygen, so the heart must work harder to provide the necessary blood flow. A high heart rate can be uncomfortable at first, but regular exercise can help strengthen your most important organ.
More oxygen enters the body
During a slow jog or yoga session, the lungs can handle the body’s oxygen needs quite easily. But during intense training, it is quickly consumed. To restore the supply, the body has to work harder, which means it burns more calories. Scientists have monitored the condition of athletes engaged on exercise bikes. They found that during 45 minutes of high-intensity workout an average of 420 calories were consumed, and during the next 14 hours another 190 calories. This means that the effect of calorie consumption increases by 37%. Does the same thing happen when you can’t tear yourself away from your favorite TV show?