Why does maximum heart rate decrease with age?

Introduction

As we all age, it seems like everything starts to slow down – our reflexes, our metabolism, and even our maximum heart rate. Yes, that’s right! The old ticker in your chest is slowly starting to lose its mojo.

But why is this happening? And more importantly, what can you do about it?

In this article, we’ll explore the science behind maximum heart rate and how it changes as we get older.

Understanding Maximum Heart Rate

Before we jump into the causes of a decreasing maximum heart rate (MHR), let’s first define what MHR means.

Your MHR refers to the highest number of times your heart can beat in a minute during physical activity without causing any damage or harm to your cardiovascular system. It’s measured in beats per minute (bpm) and plays a crucial role in determining an optimal training zone for different types of cardiovascular exercises.

For instance:

• High-intensity interval training requires 80% – 90% of MHR for maximal benefits
• Endurance running needs between 60% – 70%

So understanding your max limit allows you to choose the right type of exercise regimen suited best for you!

Causes Of Declining Maximal Heart Rate

Now that we understand what maximal heart rate means let’s dive straight into five reasons why MHR decreases with age:

1. Hormonal Changes

While both genders experience hormonal shifts throughout their lifetime, women are at risk of low estrogen levels after menopause. This decrease leads not only to disruptions occurring within menstrual cycles but also impacts bone health along with other physiological functions including cardiac muscles^(1).

The sensitivity towards norepinephrine neurotransmitters responsible for elevating one’s maximum heart rate declines resulting from less adrenaline production which occurs through advanced aging especially past middle-age^(2).

2. Alterations In Musculature

Muscle tissues surrounding the heart become more rigid with age. This can restrict healthy blood flow through different arteries leading to a higher risk of developing cardiovascular diseases^(3).

This decrease in maximal heart rate occurs due to changes in autonomic nervous system activity, there may be an attenuation of cardiac response and sympathetic nerve signals during stressors and exercise^(4).

3. Structural Changes In The Heart

As we age, our cells start getting damaged or die off which may lead to increased collagen deposits near the heart’s atria walls – this reduces the contractile efficiency (i.e., how much force it pumps with one beat). In addition, arterial stiffening leads further disturbance increasing total peripheral resistance that develops hypertension at older ages^(5).

4. Changes In Blood Volume And Circulation

The total volume of blood in your body decreases as you get older which impacts oxygen supply throughout your organism. Hence cardiac muscle has a reduced endurance capacity especially after prolonged stimulations like physical workouts where younger hearts are not affected by these factors without electrolyte imbalances.

During strenuous activities, such as high-intensity training or extreme sports e.g extreme skiing drives up metabolic demands so dramatically; even though newly developed compensatory mechanisms cannot sustain responsiveness from both chemoreceptors directly via measuring arterial pO2 level while bouncing up baroreceptor reflexes above base-line pressure values quantitatively over larger feedforward setpoints.

5. Environmental Factors And Lifestyle Behaviors

Our environment exposes us for life-long daily chronic stresses i.e pollution or noise levels along with lifestyle choices – consumption patterns & habits coupled together create individualistic aging profiles found within populations globally.

Likewise diets rich in unhealthy fats have been shown several times already working against oxidative defenses protecting one’s organ systems hence contributing directly towards MHR declines plus lipid accumulation is another vascular disease contributor.

The Effect Of Maximal Heart Rate On Exercise

While knowing one’s MHR helps in creating an appropriate exercise plan for a particular individual yet there are several key benefits of cardiovascular exercises including:

• Increased energy reserves
• Strengthened immune system
• Improved respiratory efficiency
• Better metabolism and calorie regulation

However, be cautious about overexerting yourself during high-intensity activities as this may lead to premature aging or even cardiac events. Monitoring your heart rate with wearable tech like fitness trackers is both easy and helpful!

What Does A Decline In Maximal Heart Rate Mean?

In summary; the decline of maximal heart rate is caused by complex physiological transformations happening with aging organs – smoother muscle tissues around veins making it harder pumping blood through them plus hardened arteries results when deposition collagen build-up inside atrium walls thickening resulting functionally impairments.

Moreover hormonal changes that come naturally include reduced output from adrenaline glands further affecting signal transmission coming through peripheral nerves leading reducing response overall within stressors stimuli such as exercise routines.

Conclusion

The ability to measure maximum heart rate accurately provides important information for personalized workout regimes tailored according to the strengths and weaknesses of each person.

Though you can’t prevent falling physiologically down side effects of age completely; staying active healthy living & eating habits could slow progression maximizing well-being into older years where they matter more! Keep doing what matters, keeping our generation alive longer … nearly just kidding!

Sources

1. Santosa S., Jensen M.D. Adipocyte fatty acid storage factors enhance subcutaneous fat storage in postmenopausal women Diabetes August 2015
   2.Kayser B.; Narici M.V. (1998). “EMS training Reviewed: What is electromagnetic stimulation?”. Medicine & Science in Sports & Exercise.
   3.Moritani T., Ogawa T., Yamori Y., Miyachi M.. Autonomic nerve activity contributes to the difference between intra-abdominal and subcutaneous adipose tissue oxygenation
2. Fujiwara T, Hoshide S, Kanegae H, Kario K: Changes in 24-h heart rate variability during aging and after menopause in healthy women. Hypertens Res 2007;30(9):803-809.
   5.Hidari B., Firouzian A., Veisi P., et al.. Age-associated changes of left ventricular geometry: impact on cardiac evaluation parameters Annals of Geriatric Cardiology July–December 2016