What Is Dangerously High Heart Rate During Exercise?


While it’s healthy for your heart to race during any kind of workout, it’s the dangerously high heart rate during exercise we should be concerned about.

Picture this; you are sitting on the couch, watching Netflix. Then, during a silent set on a movie, you actually hear your heart beating, fast, 100-beats-per-minute!

You try sitting up, and as you pay attention, you notice that your heart is beating way too fast. While this is common, it may not be as common as the same elevation happening during exercise.  

Of course, nobody expects to stay lake calm during vigorous training. Or during periods of extended training.  It’s normal and healthy for your heart to race as you strain up your fitness routine.

Synonymous to the engine in a car, the heart’s performance is determined by the muscles’ condition.

While the number of muscle groups is important, the ratio of fat is more essential. The physical condition is also just as crucial. When framed this way, you then understand where conditions like limited energy and quick exhaustion originate.

In addition to the degree to which a high resting heart rate affects your life, it’s also a huge health pointer. In fact, it may be a useful variable in determining your odds of dying.

This article discusses in-depth the signs, causes, fixes, and informatics on high heart rates.

Resting Heart Rate

The resting heart rate is the assumed minimum number of times the human beats at rest. This means that only basic metabolic activities are sustained.

According to the American heart association, this ideal number is placed at 60-100 beats per minute.

The difference can be attributed to surrounding factors such as age, height, fitness level, substance abuse, medication, and other conditions. These variables may cause the body to function less efficiently.

A healthy human heart is supposed to operate at its best.

The organ pumps oxygen and nutrients from the stomach and lungs to the rest of the body. The reverse is true for physiological and metabolic waste to the kidneys, liver, etc.

When you engage in physical exercise, the demands for this delivery and extraction increase, consequently, the heart beats faster.

By delivering a high volume of blood per second, the heart can catch up with the demand pattern for some time.

Two problems may arise; the demand rises too high for the heart to sustain, or the heart is in poor general physical condition.

The earlier is due to overtraining, while the latter may be caused by fitness or medical issues.

Either way, it’s not recommended to reach, leave alone staying for a long time, at maximum heart rate during exercise.

As a safety precaution, observe your heart rate. This goes for everyone and especially those who suspect to be having heart rates that are too high.

The past 100 beats per minute number form a deadly class of diseases known as tachycardia. This happens when the disease is left untreated.

The majority of people are hit with its fatality as tachycardia sometimes shows no symptoms.

Some of the lateral damage that may arise due to the disease include heart failure, stroke, and cardiac arrest.  Regardless of the cause, the following are some of the related signs and symptoms of a high heart rate.

Signs of a dangerously high heart rate

  • Fainting
  • Dizziness
  • Chest pain
  • Heart palpitations
  • Impossible to converse

When you experience any of the above, halt whatever you are doing immediately.  Allowing such symptoms for a long period may result in the lungs, brain, and other organs’ failure. The following are additional quick recovery tips:

How to recover from a dangerously high heart rate

  • Take a deep breath to help combat palpitations.
  • Run some cold water on your face
  • Avoid panicking to prevent increased heart rate.
  • Lie down flat and catch your breath

When does a high heart rate become an emergency?

If you start experiencing severe shortness of breath, chest pain, or fainting, you need to call your doctor.  This could be a sign of a serious heart complication.

Always keep within reach to access emergency services such as the police, private hospital, or general ambulance services. Although you may rarely need this, you must have it.

A 1971 Copenhagen study on 3,000 men that ran for 16 years had some interesting inferences. The resting heart rate had a direct relationship with the risk of death.  The following table sums it all 

Number of beats per minute  Percentage of elevated risk of death
50-80 lowest(<40%)
81-90 Twice 
91-100 Thrice 

How do you know your ideal heart rate?

Target Heart Rate

It’s important, whenever possible, to know your health condition. In this case, the proper knowledge of your heart would be a perfect area to begin with. In general, the human heart rate can fluctuate within some degree of the maximum heart rate.

The maximum heart rate is the safe maximum number of times your heart can beat per minute. Likewise, several factors influence this figure. They include height, level of fitness, and body composition. However, age seems to be the most influential. Therefore, we use age as the single determinant of maximum heart rate.

MHR is thus calculated by subtracting your age from 220. For example, a 30-year-old’s maximum heart rate should be 220-30=190 beats per minute. During exercise, we endeavor to rip the most benefits from our efforts. That is why it’s important to exercise at the right heart rate.  

The heart rate at which you rip the most results from your regimen is known as the target heart rate. It’s usually a percentage of the maximum heart rate; 50-85% or sometimes 50-100%.

Different rates signify unique metabolic functioning. The following table captures the ideal target heart rates for different ages:

Target Heart Rate Chart


Maximum Heart Rate 



(50-85)% MHR 



(50-60)% MHR



(60-70)% MHR



(70-80)% MHR



(80-90)% MHR



(90-100)% MHR


18 202 101-172 101-122 122-142 142-162 162-182 182-202
20 200 100-170 100-120 120-140 140-160 160-180 180-200
25 195 98-166 98-117 117-137 137-156 156-176 176-195
30 190 95-162 95-114 114-133 133-152 152-171 171-190
35 185 93-158 93-111 111-130 130-148 148-167 167-185
40 180 90-153 90-108 108-126 126-144 144-162 162-180
45 175 88-149 88-105 105-123 123-140 140-158 158-175
50 170 95-145 95-102 102-119 119-136 136-153 153-170
55 165 83-141 83-99 99-116 116-132 132-149 149-165
60 160 80-136 80-96 96-112 112-128 128-144 144-160
65 155 78-132 78-93 93-109 109-124 124-140 140-155
70 150 75-128 75-90 90-105 105-120 120-135 135-150
80 140 70-119 70-84 84-98 102-112 112-126 126-140

Ideally, 50-85% of the maximum heart rate is where you want to be. This way, your body will be operating within safe limits.

So how do you measure your heart rate during exercise?

How to Track Dangerously High Heart Rate During Exercise

There are two main ways of measuring heart rate.


This is a DIY technique. You essentially find a pulse from any part of your body; wrist, arm, etc. You then lightly press on the pulse with one or two fingers. Count the number of pulses for 1 minute. You can also count the number of beats for 30 or 15 seconds. In which case, you will multiply the values by 2 and 4, respectively. This will give you the measurements in beats per minute.


This is by the use of a heart rate sensor. 

These tiny devices use either light or quartz crystals to detect the number of times the heart-beats.

They come in various form factors; chest strap, smartphone, smartwatch, or wrist sensors.  The majority of the latest iterations of these gadgets have excellent smartphone connectivity.

This allows you to track your heart rate throughout a training session. With advanced analytical software, this information can be deciphered and presented in simple infographics.

You also have the ability to set alarms for when dangerously high heart rates are detected. This can easily be set and synced with the sensor. Thus, it provides great utility in terms of safety.

Frequently Asked Questions (FAQs)

#What is too high of a heart rate during exercising?

Heart rates higher than your maximum heart rates are dangerous. Maximum heart rate is calculated by subtracting your age from 220. We have outlined the MHR for the different ages in earlier sections of this article.

#What happens if you exceed your maximum heart rate?

You will experience extreme musculoskeletal injuries. This could lead to sore joints and muscles. 

#Why is my heart rate so high when running?

As you run, the heart beats faster to deliver more oxygen and nutrients to your muscles. Upon metabolism, lactic acid and carbon dioxide are released. This loads the heart further. And the cycle continues.

#At what heart rate should you go to the hospital?

Anything above 100 or below 60 beats per minute, consistently for a minute, should be treated as an emergency.

#What happens if your heart rate gets too high?

The myocardium muscles, which power the heart, may become oxygen-deprived. This can lead to a heart attack.

Bottom Line

As discussed, ensure that you stay within the recommended safe heart rate limits. This is usually 50-85% of your maximum heart rate.

Invest in an accurate heart rate measuring device to stay alert. 

Otherwise, focus on consistency. Regardless of the level of your effort, seek to challenge yourself to do better every day. Within safe limits, of course!


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