The aim of the work was to study the body reaction to high intensity interval training. The study included 92 women aged 18 to -35. People who have been engaged in organised, regular physical activity (at least twice a week) were qualified to Group 1. Group 2 were physically inactive persons. All subjects performed interval training in the Tabata formula - two 4-minute sequences. The exercise carried out in the first part is elevating the legs from the “plank” position, in the second part, the hands were elevated from the same position. The pulse rate, the Borg Scale and the VAS pain rate scale (24, 48, 72 and 96 h after exercise) were used to assess the exercise intensity. The respondents from both groups performed the training at a similar intensity: the average heart rate after workout was 131 beats per minute. The highest pain of all muscle groups (when added together) was recorded 24 hours after training. The highest pain intensity during the four days after the training concerned the back and abdominal muscles in Group 1 and the muscles of the abdomen, back and arms (front and back). The intensity of abdominal and arm muscle pain (front) was significantly higher in Group 2. The proposed 15-minute workout planned in the form of Tabata evoked similar cardiovascular reactions in both groups and a similar subjective evaluation of intensity. Individuals who were physically active before the introduction of restrictions related to the COVID-19 pandemic had less pain in the muscular system after the applied training.