You might gain muscle

The majority of HIIT exercises involve many different movements. This enables you to work out many muscle groups at once. For example, a HIIT workout may involve doing exercises that target different muscle groups, such as squats, push-ups, and burpees.

The intensity will also help in muscular growth and increase your muscles' ability to endure more workouts. Due to the lack of rest, this type of training increases physical endurance. For example, a 2017 study found that a six-week HIIT program increased men's peak power output, a measure of muscular power (PPO). The average absolute PPO for men was 799 watts before the HIIT training, and it increased by around 8% to 865 watts after. A 2017 research also revealed that among overweight female teens, a 12-minute HIIT workout had a greater impact on the muscles than a 40-minute aerobic workout. This was determined by observing the levels of irisin, a hormone that muscles release after exercise.