If you feel as though your get-up-and-go got up and went, or find yourself winded with little effort and your heart racing during light activity, this could be due to a number factors which influence fatigue and energy levels. A heart rate that rises easily with minimal effort is a good indication that some lifestyle changes are in order. Consult your doctor about your proper heart rate and before beginning any new diet or exercise regimen.
Read more: Cardio Heart-Rate Zones
The Cardiovascular System
Your cardiovascular system involves your heart, lungs, arteries, veins and capillaries. It is how your body delivers oxygen and nutrients to and removes waste from all its cells. When all components are healthy, your body hums along without a hitch. But when one or more components are not up to snuff, the entire system is compromised. Diminished oxygen delivery to the cells will manifest as physical lethargy and fatigue. Diminished oxygen to the brain will interfere with focus and alertness.
Resting and Exercise Heart Rate
Your heart rate at rest is a good indication of heart health. According to the Mayo Clinic, the average adult resting heart rate is between 60 and 100 beats per minute, while a trained athlete may have a resting heart rate as low as 40 beats per minute. When the heart muscle is strong and the lungs and cardiovascular system are healthy, the heart pumps more blood per beat, a measure known as stroke volume. Greater stroke volume means the heart has to beat fewer times per minute to meet the oxygen needs of the body. Regular exercise cultivates a lower resting heart rate.
Hemoglobin and Fast Heart Rate Causes
Hemoglobin is a protein your body manufactures from dietary iron, and serves as the oxygen-carrying component of red blood cells. When hemoglobin levels are low, even an otherwise-healthy cardiovascular system cannot properly oxygenate all the cells. Low hemoglobin is clinically known as anemia.
The National Heart, Lung and Blood Institute lists increased heart rate and fatigue as symptoms of iron-deficiency anemia. The heart rate rises easily in an attempt to meet the body's oxygen requirement by pumping more blood per minute. Taking an iron supplement or increasing your consumption of iron-rich foods like red meats and leafy green vegetables can reverse iron-deficiency anemia; consult your doctor before taking any supplements.
Read more: Cardio Exercise Heart Rate
Stress and Other Lifestyle Factors
Because stress and sleep deprivation alter body chemistry, they can have a negative impact on heart rate and blood pressure. Low muscle mass and high body fat are also associated with elevated heart rate. Muscle drives your metabolic engine, keeping it revved up all day. Fat is dead weight, weighing you down and making your heart work harder during everyday activities. Dehydration will cause elevated heart rate because your body's systems are stressed when fluid-deprived. Cigarette smoking and excessive caffeine consumption are also culprits, and can cause a sudden increase in your resting heart rate. Managing stress, getting ample sleep, staying active and keeping hydrated will lower resting and exercise heart rate over time.
Staying Heart Healthy
The Centers for Disease Control and Prevention recommends a minimum of 150 of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity aerobic activity each week. Activities like walking, swimming, bike riding and gardening all qualify, so long as they elevate your heart rate to above-resting levels. The CDC also recommends resistance training twice weekly to build muscle. Keeping your heart and body strong will give you energy and stamina to do everyday tasks with less effort.