How Hard Can I Exercise After a Heart Attack?

Are you concerned about increasing your heart rate with exercise after your heart attack? Looking for a little guidance?

Managing your exercise intensity is an important factor in your recovery after a heart attack. First and foremost, begin by speaking to your doctor to get the thumbs up to start exercising. Also, I would highly recommend speaking to your doctor about getting a referral into a cardiac rehabilitation program like ours!!  As experts in the field, we can look at your specific heart health history & safely guide and support you, step by step, in your recovery.

There are a number of factors to be aware after a heart event that can impact your ideal exercise intensity. Here are a few:

  1. Heart function:
    1. How much damage was there to your heart? What is your heart’s ejection fraction? – Ask your doctor about this.
    2. Do you have heart rhythm issues? Pacemaker or ICD? There may be certain heart rate ranges that you need to stay within.
    3. Do you have other narrowings or blockages in your coronary arteries?
  2. Medications:
    1. Some medications such as beta blockers (Metoprolol, Bisoprolol) or some Calcium Channel Blockers (Diltiazem) will lower your heart rate.
  3. How do you feel:
    1. How is your energy?
    2. Do you get angina symptoms?
    3. Does your blood pressure respond normally to exercise? (Goes up during exercise, and comes back down afterwards)

With that being said, the sooner we can get you up and moving the better. The goal is to progress slowly and build a solid foundation. For those who have been diagnosed with heart disease some time ago, the goal is to be exercising at a level to slow and even perhaps reverse the disease progression.

In terms of giving you an actual exercise target heart rate. First, we look to see if you have had a treadmill stress test, as this will give us a great guideline on the exercise intensity your heart is happy with. We will use this test as a guide (if you haven’t had one, that’s ok) in addition to using what is called the Karvonen Formula.

The Karvonen Formula is a calculation that uses your resting heart rate as well as your age to determine your exercise heart rate zones. Unlike other standard calculations used on gym equipment scales for example, using your specific resting heart rate allows the calculation to be more individualized for you. It is better able take into consideration the fact that you are on heart rate lowering medication, as the resting heart rate we use, is while you are currently medicated.

Karvonen Formula – %max HR (Max HR – Resting HR) + Resting HR

  1. To start figure out your Max Heart Rate:
    If you are 50+ use this equation: 208 – 70% of your age = Max HRSo, for example: If you are 65 years old – 70% of your age = 45
    Max Heart Rate = 208 – 45 = 163bpm
  2. What is your resting Heart Rate: Sit quietly for 5 – 10 mins. What is your Heart Rate? This isn’t necessarily your true resting.. but it will be a good guide. Make sure you have taken your medication prior. For this calculation we will say your resting is 55bpm.
  3. What is the % of Max HR – This can range anywhere between 40 – 90% depending on your heart and your stage of recovery. Typically 60 – 75% is the average. (This is where cardiac experts to guide you is helpful!)
  4. Perform the calculationExample using 60% Max Heart Rate. 65 year old. Resting heart rate of 55bpm.
    % Max (Max HR – Resting HR) + Resting HR
    60% (163 – 55) + 55
    .6 (108) + 55
    64.8 + 55
    = 119.8 bpm = roughly a heart rate of 120bpmThen you would figure out the heart rate using 75% Max to give you a heart rate range to use as a guide for your exercise session.

Now having said ALL of this.. the real guide should be how you feel. No matter what, how you feel is priority number one versus trying to get your heart rate to a specific number. You want to feel comfortably challenged. You want to feel like your breathing has increased but you are able to talk. You have no pains or symptoms and although you feel you are working, can maintain your pace.

There are many types of cardiovascular training, such as steady state training where you walk at a continuous pace for a period of time, and interval training, where you work at a higher intensity for a short window of time followed by a slower recovery phase. Talk to your cardiac rehabilitation experts about the style of training that would be best suited for you.

Exercise intensity, as it relates to the slowing of disease progression and the potential regression of disease, is extremely important. Many people are doing great at working towards 10,000 steps on their pedometers or 150mins of exercise per week. However, although increasing your steps absolutely has overall health benefits, many of those steps are not at an intensity high enough to really impact disease progression.

To slow the progression of disease we are looking for you to expend about 1500 or more kcals per week. What does that mean?

It means if you normally go out for a slow walk or easy stroll, you need to be strolling for about 90 mins a day. However, if you normally go for a brisk walk (3.5 – 4mph) you need to be walking for about 35 – 40 mins per day. I can here you saying.. WHAT?? I can’t walk that long? I can’t walk at that pace? Don’t worry.. we have solutions.

Many of us do not exercise daily, many of us count those strolling steps as part of our daily step count. Again.. all movement is great!.. this is just to show you that exercise intensity matters if we want to slow the disease progression. If you are one of those people where the exercise times and intensities I just described have you concerned, don’t worry. We have not even begun to talk about strength training yet, which really is where the magic happens. Especially as we get older!

This is a big topic, and I am really just touching the tip of the iceberg here. I am happy to help in any way I can, so I encourage you to contact us. Set up a consultation and we will go over everything!

Shawna Cook

Shawna is a Certified Clinical Exercise Physiologist through the American College of Sports Medicine, who has been working in Cardiac Rehabilitation for over 10 years. Her years in the health and fitness field however have spanned over the past 2+ decades. As an elite level athlete she fell in love with understanding the human body, and how the choices she made, affected how it performed. This led to a degree from the University of Winnipeg in the stream of Athletic Therapy, and the passion towards helping others recover from injury and "be their best selves" grew.