Typical symptoms of a low heart rate include weakness, dizziness, memory problems and shortness of breath, according to Mayo Clinic. These symptoms occur due to an insufficient supply of oxygen to the brain and other vital body organs.
According to the American Heart Association, heart rate is affected by factors both inside and outside the body. Body size, body position, personal emotions and use of certain medications can affect heart rate, although in some cases to a minimal extent. Air temperature also has a small effect on he
The body controls the heart rate through its own electrical system that ensures blood flows through the heart and lungs in a controlled manner. Issues with the electrical system, such as an arrhythmia, can cause problems with a regular heart beat and how the body controls heart rate.
Caffeine increases a person’s heart rate because it is a central nervous system stimulant, says MedlinePlus. It is absorbed and passed quickly into the brain and stimulates the brain and nervous system.
A heart rate of more than 100 beats per minute in adults, a condition called tachycardia, is considered fast according to The American Heart Association. However, what is considered fast depends on the age and physical condition of an individual.
Effects of slow heart rate, or bradycardia, include dizziness, shortness of breath, tiredness and chest palpitations, according to WebMD. People who have slow heart rate may also feel confused or faint.
Normal resting heart rate for adults is between 60 and 100 beats per minute, according to the Mayo Clinic. Resting heart rate varies considerably by age, but after 16, teenagers have the same normal range as adults.
When a resting heart beats less than 60 times per minute, it is a lower-than-normal heart rate, called bradycardia, states WebMD. A low heart rate can be a sign of fitness, as in athletes and healthy young adults, or a sign of a problem with the heart's electrical system.
A heart rate is obtained by feeling for the pulse at one of the body's pressure points and tracking the number of beats for a set period of time, according to the American Heart Association. The goal is to determine the number of beats in one minute.
Target heart rate calculators are tools that are used to determine heart rate ranges for physical exercise, according to Active.com. By accounting for age and exertion level, these calculators give users a good idea of how hard they should be pushing themselves while exercising.