Reasons

List of possible causes

Reasons for a faster than “normal” heart rate can be divided into three main categories:

  1. Physiological reasons
  2. Pathological reasons
  3. Environmental influences and external factors

A simple method to evaluate or predict heart rate during a training is to ask yourself these six questions:

  1. How do I feel today?
  2. Was/am/will I possibly get sick?
  3. Am I trained well or did I pause – what is my fitness level? Alternatively, you can measure your resting heart rate variability.
  4. Am I under a lot of stress recently?
  5. Did I drink enough?
  6. What are my hormones level? (mostly relevant for women)

Write down answers to these questions next to a training workload in your training journal and pay attention to it. You will see that if you have a deficit, your body will compensate for this with increased blood and oxygen transport. This leads to an above-average pulse. If you are healthy, trained and well prepared, your pulse will meet your expectations again.

To know what your body can perform also means to be aware of your mental state – the interplay of body and spirit is more important than many athletes realize. 

Convenient Measurement of HR, HRV and body temperature

Psychology

Physical and biochemical reasons

Heart rate in general is depending on the beat volume, i.e. the amount of blood the heart is able to pump with one beat, and on the volume of blood needed by the body per time unit. Factors influencing these two parameters are:

  • Age
    • The heart rate of each person is age-dependent. Children e.g. have a particularly high heart rate due to their lower cardiac output. This, however, changes with time as they grow up. There are several methods how to calculate approximate age-dependent maximum heart rate: 208-0.7 x age (from Hirofumi Tanaka) or Hossack: 206-0.597 x age for women (♀) and for men 227-1,067 x age (♂ ).
  • Gender
    • The heart rate is also gender-dependent. Women tend to have higher heart rates than men. This is due to the heart size — the smaller the heart the smaller is the beat volume and therefore pump frequency needs to be higher.
  • Level of fitness
    • Heart rate is dependent on your fitness level. Athletes tend to have lower heart rate than regular people because their beat volume increases with exercise.
  • Training schedule and intensity
    • Too intense and/or too often trainings can reflect in an increased heart rate. Due to excessive training load the body can get into an overtraining condition and therefore respond with increased heart rate.
  • Bodyweight
    • An increase in body weight could be a reason for increased heart rate as well. A heavy body has to do more work than a lighter one to perform the same movement. So more blood is needed. Beat frequency needs to be higher.
  • Type of movement
    • Heart rate is different for different types of movement. For example, the walking heart rate is approximately 8-12 beats higher than when cycling. This is due to the extent of carrying your own body weight and thus the need for using larger muscle masses.
  • Food
    • The need for increased blood flow in an intestine due to larger meals leads also to an increase in heart rate.
  • Stress
    • Mental stress leads to higher heart rate in rest and during exercise.
  • Pregnancy
    • Another reason for increased heart rate in women may be a pregnancy. Due to the hormonal changes and the increased need for oxygen, the heart rate increases.

Pathology

Pathological reasons

  • Infection
    • An imminent, acute or delayed infection leads to an increase in heart rate and body temperature due to the inflammatory reactions in the body.
  • Heart
    • Heart defects can cause an increased heart rate.
    • If a heart suffers from a functional disorder, the increase in heart rate can be a compensation for this heart malfunction.
  • Blood vessels
    • Disorders of the blood vessel system can be responsible for an increased heart rate.
  • Thyroid
    • Problems with thyroid gland can cause changes in the average heart rate.
  • Hormones
    • Hormonal disorders that directly affect the control of the heart rate and are responsible for the production of stress hormones such as
      • cortisol
      • Epinephrine / norepinephrine

      increase the heart rate.

Environmental influences and external factors

Altitude, temperature and fluids

  • Altitude
    •  In case of being in places positioned in higher altitude, oxygen level in the air decreases so that the body needs to increase breathing rate to receive same amount of oxygen as in lower altitudes. This additional load is projected in higher heart rate.
  • Temperature
    • Higher outside temperature leads to loss of body water as you become dehydrated plasma volume decreases, making the blood more viscous. This in turn increases heart rate.
  • Liquids
    • Not drinking enough, especially at high external temperatures, does increase heart rate.
  • Medication and supplements
    • Various medications and supplements can cause higher heart rate.

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