It sounds like you’ve found some activities you enjoy and are sticking with them — good for you! The U.S. Department of Health and Human Services recommends a minimum of 150 minutes/week of moderate cardiovascular exercise, OR 75 minutes/week of vigorous exercise, OR some combination of the two. That works out to about 30 minutes, 5 days a week of moderate exercise, like brisk walking; or 25 minutes, 3 days a week of vigorous exercise — activities like running, lap swimming, and some higher-intensity group fitness classes.
In an ACE-sponsored Zumba® study classes were found to be highly effective in building cardiovascular fitness, core strength, and flexibility; subjects burned an average of 369 calories, or 9.5 calories/minute during a Zumba® class and kept their heart rates at a level needed to achieve fitness benefits. Many people report burning far more calories in a single Zumba® class, but that depends on your body size, body composition, and effort level.
No matter what activity you choose, your actual intensity depends on how much effort you put into it. You could take it easy, go at a moderate pace, or turn up the heat and give it everything. There’s nothing wrong with any of these approaches, as long as you’re getting what you want out of your workout. But if your goal is to increase fitness, you’ll need to work at a moderate-to-vigorous pace.
If you perform your twice-weekly Zumba® sessions at a moderate pace, and the cardiovascular portion of class is 45 minutes (excluding warm-up and cool-down), that’s 90 minutes a week; you could benefit from 60 additional minutes a week to meet the minimum guidelines for good health. So you could add a couple of brisk 30-minute walks to your weekly schedule, or add another Zumba® class plus a 15-minute walk.
If you’re performing Zumba® at a vigorous intensity, you’re already exceeding public health recommendations for total minutes of cardiovascular exercise. The American College of Sports Medicine recommends a minimum of 3-5 days/week of cardiovascular exercise, so consider adding a third day of Zumba® or another activity of your choice.
The more exercise you do, the more benefits you’ll experience. Even greater physical and mental health benefits are associated with getting 300 or more minutes a week of cardiovascular exercise; that’s about 60 minute a day, 5 days a week — and it doesn’t have to be done all in one session.
A minimum of 2 days/week of strength training is recommended, so you’re already meeting that standard.
You’re definitely on the right track. With another cardio workout or two each week, you’ll boost your fitness level and enhance your health-related quality of life. Keep up the great work!