Eryn Smith is passionate about exercise. It all began nine years ago when he decided to take control of his health, resolving to mitigate his risk of developing diabetes and heart disease, conditions that run in his family.

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He's also a physician assistant with the Michigan Medicine Frankel Cardiovascular Center, so when it comes to questions about a heart-healthy workout, this 44-year-old cycling enthusiast has the answers.

And, he has the motivation.

Smith's cycling goal is to ride 5,000 miles in 2019, which equates to 100 miles a week. He rides indoors during cold months and outdoors when weather permits, racking up the miles and training for various cycling competitions.

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"On the days I don't ride I typically use an elliptical trainer for 30 to 45 minutes and I try to get in at least two days of weight training along with the cardio," says the Saline, Michigan, resident.

For those who find excuses to avoid exercise, Smith has convincing evidence of its advantages, particularly for the heart and arteries. "Any exercise that raises your heart rate is beneficial to your health," he says.

Tips for a heart-healthy workout

My cardiologist tells me to I should try to lose some weight. Will exercise help me do that?

Smith: You won't necessarily lose weight from exercise alone. The lion's share of weight loss comes from restricting calories, but when you add cardio to the mix, you're boosting your metabolism, which helps to speed up weight loss.

For my patients who are frustrated because they're cutting calories but have come to a plateau with their weight loss, I suggest adding cardio to fire up their metabolism. I remind them that a successful weight loss program involves a diet and exercise plan that works for them — one that they can continue for the rest of their life.

What is the best cardio for keeping my heart healthy?

Smith: The best cardio is something you enjoy doing that won't lead to injuries. Running, for example, is hard on the joints, so be careful not to overdo it if you choose to run.

An elliptical machine and stationary bike are good choices. I strongly recommend the elliptical, which is easy on the joints, plus, it allows you to increase your resistance and keep an eye on your heart rate throughout your workout.

Ideally, you should do a 30- to 45-minute cardio workout 7 days a week. When beginning an exercise program, be sure to start out slowly and gradually increase your heart rate. And always consult with a health care provider before you begin.  

What if I can't fit a full 30- or 45-minute workout in?

Smith: Dividing your workout into 10- or 15-minute segments throughout the day is fine, but I tell my patients to try to fit the entire workout into one segment. I think about it this way: One body, one heart. No matter how busy you are, realize the importance of exercise for your heart and overall health. Make it a priority and set aside time for it.

I have the mindset that working out on a daily basis is critical. I make sure I plan out my time to do it every day. Sometimes that means I'm working out after my sons go to bed at 9 o'clock (after I've worked a 12-hour day), but that's just how it goes.

I try to be a role model for my sons as much as possible, but I'm deliberately not pushing them too hard. I don't want them to see exercise as a chore that they have to do, but as a fun, routine part of life.

What about weight training?

Smith: Weight training is good for certain muscles, but when it comes to the heart muscle, you really need regular cardio workouts.

What are the actual benefits of exercise for my heart?

Smith: Your heart is a muscle that needs to be exercised. When you increase your heart rate through exercise, you're causing your heart to beat harder so that more blood is being pushed through it. As a result, your heart muscle becomes stronger.

It's the same concept as working out your biceps: The more you work the muscle, the stronger it gets.

A cardio workout also benefits your vascular system. When the blood is being pushed out of your heart and into the arteries, they're being stretched — in a good way.

Many people experience hypertension and stiffening of the arteries as they age, but you can fight it by getting regular cardiovascular exercise. When you exercise, the arteries are being forced to open to let the extra blood through. In a way, you're training your arteries to be strong, which improves blood flow.

Cardio exercise is also a great stress and anxiety reliever.

What about patients with a heart condition?

Smith: Cardiovascular exercise is a critical part of a heart patient's treatment plan once their condition has stabilized and when approved by their health care provider.

These patients need to be closely monitored during exercise, ideally at a cardiac rehab center where trained professionals can help guide their workouts or at a facility with a personal trainer who can advise them.

What else do you recommend for a heart-healthy workout?

Smith: I highly recommend using a chest strap heart rate monitor that allows you to see how much effort you're putting into your workout. A monitor can let you see your heart rate during your workout — it'll show you when you need to pick up the pace or slow things down.

Are there age restrictions for working out and intensity levels?

Smith: It's never too late to begin an exercise program and to realize the benefits to your cardiovascular system. A 30-year-old is probably better able to handle a high-intensity workout than a 70-year-old, but it's important to do as much as possible, always with your health care provider's approval.

Start out slowly and push yourself to do more.