In general, it is recommended to take a rest day every 2-3 days if you are alternating strength and cardio exercises. This allows the muscles to recover and prevents overtraining, which can lead to injury or burnout.The frequency of rest days needed to recover when alternating strength and cardio can depend on several factors, including:1. Intensity and duration of the workouts: The more intense or longer the workouts are, the more rest your body will need.2. Fitness level: Individuals who are in good physical condition may be able to exercise more frequently without needing rest days, while those who are just starting out or have medical conditions may need more rest days.3. Overall health: Health factors, such as stress levels, sleep habits, and nutrition, can impact the body's ability to recover from exercise.