By shortening your rest intervals, you’re automatically increasing the intensity of your workout and keeping your heart rate elevated throughout your weightlifting or interval training session. This cardio challenge trains your body to work efficiently and persevere through fatigue. When you do cardiovascular training regularly, your body gets better at delivering fresh oxygen to your muscles, so you’ll actually get better at pushing through your workouts even when you’re tired.
The right amount of rest varies depending on the workout and the person, but as a rule of thumb, you should aim to take just enough that you can go hard during your next set, but not so much that you’re totally recovered. A disclaimer: too little rest won’t allow your muscles to recover enough to be ready for your next strength set.