Do I have to do cardio to lose weight?
If your goal is fat loss, the answer is NO! But that does not mean that you can give up on cardio for some of the other health benefits that it provides.
Now, while cardio isn't necessary for weight loss, that doesn't mean cardio is unnecessary ~in general~. The American Heart Association currently recommends 150 minutes of moderate cardiovascular exercise per week (spread over five days) OR 75 minutes of vigorous cardiovascular exercise per week (spread over three days) plus two strength training sessions for optimal heart health. (Only about 23 percent of Americans are meeting those requirements, though.) That's because getting your heart rate up is still crucial for keeping your heart healthy.
The thing is: Strength training, when done strategically, can definitely get your heart rate high enough to count as vigorous cardiovascular exercise. (Here's a primer on how to use heart rate zones to train for max exercise benefits.) "Compound movements are a great way to get your heart rate up while doing strength training," explains Gozo. Because you're working several muscles at once, your heart rate is going to climb. (If you've ever heard your heartbeat in your ears after doing a few heavy deadlifts, you know exactly what she's talking about.) Plus, by minimizing the rest you take between sets, adding heavier weights, and/or stepping up your pace, you can boost your heart rate.
See Shape Article 6 Jul 2018