<human>:  What is the most efficient way to exercise?
<bot>: The most efficient way to exercise is to do high-intensity interval training (HIIT). This type of exercise has been proven to have numerous health benefits and can help you get the most out of your workout in a relatively short period of time. It involves alternating short bursts of intense exercise with periods of rest. This efficient type of exercise has been shown to boost metabolism, increase endurance and muscle strength, and improve cardiovascular health.