While HIIT workouts are effective for boosting cardiovascular fitness, building muscle strength, and improving energy levels, trainers recommend not doing them daily as they can lead to overtraining, injuries, and burnout. 

High-intensity interval training (HIIT) is a form of exercise that alternates short bursts of intense activity with recovery periods of lower-intensity exercise or rest. It is an effective way to boost cardiovascular fitness, build muscle strength and endurance, and improve energy levels while reducing the risk of health issues like type 2 diabetes. However, trainers recommend not doing HIIT workouts daily, which can lead to overtraining, injuries, and burnout. The general recommendation is to do HIIT workouts no more than two to three times per week, allowing at least 48 hours between sessions. Opting for slightly easier exercises and taking rest days can also help prevent overdoing it with HIIT. 

Source: https://www.bustle.com/wellness/can-you-do-hiit-every-day