The relationship between athletic training and blood pressure is complex. While many assume an active lifestyle protects against high blood pressure, athletes can still experience elevated readings. This article explores how exercise influences blood pressure and factors contributing to higher readings in athletes.
Understanding Blood Pressure
Blood pressure refers to the force exerted by circulating blood against the walls of the body’s arteries. It is measured using two numbers: systolic and diastolic pressure. Systolic pressure, the top number, represents the pressure in the arteries when the heart contracts and pumps blood out. Diastolic pressure, the bottom number, indicates the pressure in the arteries when the heart rests between beats.
Both measurements are expressed in millimeters of mercury (mmHg). A blood pressure reading is typically written as systolic over diastolic, such as 120/80 mmHg. For most adults, a normal blood pressure reading is generally considered to be below 120/80 mmHg. Readings consistently at or above 130/80 mmHg are often classified as elevated or high blood pressure, also known as hypertension.
Athletic Training and Blood Pressure Regulation
Regular physical activity generally leads to lower resting blood pressure in athletes compared to less active individuals. Aerobic exercise, such as running, swimming, or cycling, strengthens the heart, allowing it to pump more blood with less effort. This increased efficiency reduces the force on blood vessel walls, contributing to lower blood pressure.
Physical training also improves the elasticity of blood vessels, helping them expand and contract more easily, which in turn reduces overall pressure. Adaptations include a decrease in systemic vascular resistance, meaning the blood vessels offer less resistance to blood flow. Furthermore, exercise can lead to reduced activity of the sympathetic nervous system, which controls the body’s “fight or flight” response and can constrict blood vessels.
Endurance training has been shown to induce reductions in both resting and daytime ambulatory blood pressure. Meta-analyses indicate aerobic endurance training can reduce systolic blood pressure by 3.0 to 7.0 mmHg and diastolic blood pressure by 2.4 to 4.9 mmHg, with greater reductions in those with existing hypertension. While aerobic exercise is particularly effective, dynamic resistance training can also contribute to lowering blood pressure. Resistance training can also lead to an average reduction of 2.6 to 3.9 mmHg in systolic blood pressure and 2.7 to 3.9 mmHg in diastolic blood pressure.
Factors Contributing to Elevated Blood Pressure in Athletes
Despite the overall benefits of exercise, athletes are not immune to developing elevated blood pressure. Genetic predisposition plays a role, as a family history of hypertension can increase an athlete’s risk regardless of their fitness level. Certain dietary habits, such as a high intake of sodium, can also contribute to elevated blood pressure in athletes.
Stress, both from intense training demands and external pressures, can also influence blood pressure readings. Certain supplements or medications, including NSAIDs, decongestants, stimulants, and anabolic steroids, can also increase blood pressure. Less common underlying medical conditions, such as renal disease or diabetes, can also cause secondary hypertension.
Specific training modalities and overtraining can also elevate blood pressure. Intense resistance training, especially heavy weightlifting involving maneuvers like the Valsalva maneuver (holding breath during exertion), can cause temporary spikes in blood pressure, with readings exceeding 480/350 mmHg during maximal lifts. While these are acute responses, chronic exposure to such pressures or inadequate recovery from intense training, known as overtraining syndrome, can lead to persistently higher resting blood pressure and heart rate. Higher rates of hypertension are also observed in athletes in sports with high static demands, such as weightlifting and football, compared to endurance athletes.
Importance of Monitoring and Evaluation
Regular blood pressure monitoring is important for athletes, as their active status does not guarantee healthy blood pressure levels. While athletes generally have a lower prevalence of high blood pressure than the general population, some can still develop hypertension. Monitoring helps identify any abnormalities, allowing for early intervention and management.
Medical professionals play an important role in evaluating an athlete’s blood pressure, interpreting readings within the context of their training and overall health. Factors like “white coat syndrome,” where readings elevate in a clinical setting due to anxiety, should be considered. Out-of-office measurements, such as ambulatory blood pressure monitoring, are often recommended to confirm hypertension in athletes. This comprehensive approach ensures accurate diagnosis and appropriate guidance for maintaining cardiovascular health and optimizing athletic performance.