What should my heart rate be during cardio exercise?

Michael L. Arcarese, MD
Internal Medicine
During cardio exercise, a good heart rate depends on your goals. In this video, Michael Arcarese, MD, an interventional cardiologist at Chippenham & Johnston-Willis Hospitals, describes what your heart rates should be to lose weight and get fit.  

Your current fitness level determines what a safe heart rate percentage is for you. It's very important to first determine your max heart rate so start by subtracting 220 from your age. So, if you are 40, take 220-40 and your max heart rate is 180. Once you have that number you need to find the zone that you should exercise in by, taking your Heart Rate max times the following percentages.

Zone 1 is for beginners - HRmax x 0.65 to 0.75: If first-time exerciser use HRmax x 0.50 to 0.65

Zone 2 is for healthy active adults - HRmax x 0.80 to 0.85

Zone 3 is to be used by high level athletes or adults approved by a physician - HRmax x 0.86 to 0.90


Wendy Batts

Start by subtracting your age from 220. This is a theoretical heart rate that is considered your maximum. If you are new to increasing your activity, build toward working out at 60% of this number. For example if you are 40, your theoretical maximum heart rate is 180 and 60% of that is 108 beats per minute. Warm up for 5 minutes then increase intensity until you reach 60% of your heart rate max. Maintain it only for as long as you are comfortable, even if only for a few minutes. Work toward maintaining it for 30 minutes. Attempt this for 2-3 days per week. Remember though, that the formula is a rough estimate and a good place to start, and is not the definitive measure of intensity.

Also use a talk-test to see how hard you are working. At 60%, you’ll be able to comfortably deliver full sentences. If you start gasping or can only get out single words at a time, you are working too hard. Once you can master working out at 60% (2-3 days per week for 30 minutes at a time without any problem), you can begin to increase your intensity and/or time.


To find the heart rate you should reach during cardio, you first want to take 220 minus your age. For example if you are 35, 220-35= 185. Once you have that number you need to find the zone that you should exercise in by, taking your Heart Rate max times the following percentages. Zone 1 is for beginners, Zone 2 for healthy active adults and Zone 3 is to be used by high level athletes or adults approved by a physician.

Zone I: HRmax x 0.65 to 0.75: If first-time exerciser use HRmax x 0.50 to 0.65

Zone II: HRmax x 0.80 to 0.85

Zone III:  HRmax x 0.86 to 0.90

Dr. Michael Roizen, MD
Internal Medicine
Your heart rate has to be 80% of your age adjusted max. Your age adjusted max is 220 minus your age for men, 208 minus 82% of your age for women. The easy way is 220 minus your age, take away 20%. To be in the optimal cardio range, your heart rate has to be at 80% of your age adjusted cardio max.  Even better if it is at 100%. You are really buff if you get it to 110%. Don’t try that at home unless your first name is Mehmet.
Robert S. Kaufmann, MD
Internal Medicine
Typically your heart rate should be 75 to 80 percent of your maximum heart rate (MHR)  To calculate your MHR is 220 minus your age.  My MHR is 220 - 51 = 169.  You must also figure your fitness goals.  
Start by determining your maximum heart rate. I suggest the following formula:
220 - your age = estimated maximum heart rate.
Take the estimate and multiply by appropriate intensity (this will vary between 40% and 90% depending on your physical condition).
Example - 50 year old female starting a cardiovascular fitness program after 10 years of activity
220 - 50 = 170 (maximum heart rate). 170 X 50% (suggested target rate based on starting condition) = 85. On a 10 minute walk the target heart rate should be around 85 for at least 5 minutes.
Important to be able to monitor heart rate during exercise. 

Your heart rate zone is determined by your fitness level and your specific goals. Your heart, which is made of cardiac muscle, needs to be trained specifically, just like you would train your biceps or chest muscles in a specific way with specific exercises. There are 3 target heart rate zones, zone 1 is 65 - 75% MHR, zone 2 is 80-85% MHR, zone 3 is 86-90% MHR (do not stay in zone 3 longer than 1 minute). MHR is maximum heart rate is figured using the formula 220 - age, that number multiplied by heart rate zone %:
220 - 47 = 173 MHR
173 x .65 = 112.4
173 x .75 = 129.7
This individuals zone 1 heart rate range is between 112 bpm - 129.7 or 130 bpm. The other 2 zones are figured using the same formula. Once you have these ranges you are ready to start your cardio interval training program. This type of program will have you burning more calories in 30 minutes than you would if you just went at a steady rate for the same amount of time.

To start you only use the zone 1 range. You will need a heart rate monitor to keep track of your bpm. Keep your heart rate in zone 1, when your heart rate is to high, decrease the workload and vice versa. When you can keep your bpm in zone 1 for 30 minutes 5 days in a row you are ready to add zone 2 into the rotation. Then you use intervals of zone 1 & 2. and so on.

Zone 1 becomes your base range, the range you want your heart rate to drop back to when your bodies emergency response system kickes into high gear - like when the phone rings in the middle of the night. You do not want your heart rate and blood pressure to go really high and stay there to put you at risk for heart attack or stroke. The interval training trains your heart to drop its bpm back down after the stessor is relieved. Your resting heart rate will improve and you will burn more calories with less time on the treadmill or bicycle. I would love the opportunity to set up a cardio interval training program just for you.

Your heart rate (and exercise intensity) is highly dependent on your fitness goals. When starting out a new program, an intensity of 65-75% of maximum heart rate (MHR) is recommended. If the goal is to increase overall strength and endurance, aim for 80-85% MHR. Finally, if the goal is to increase work capacity at high levels, work up to 86-90% of MHR.
This can be calculated as follows:
  • 220 – age = MHR
  • MHR x training intensity = suggested heart rate
  • Ex: 220-25 = 195
195 x .80 = ___
195 x .85 = ___

Continue Learning about Evaluating & Measuring Fitness

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.