Wednesday, December 21, 2016

Another reason to exercise every day during the holidays

TheConversation: Yes, of course we all know we should exercise every day during the holiday season to help counter the onslaught of excess calories that started on Thanksgiving and will mercifully end with a New Year’s toast. We may even tire of hearing about exercise and weight from family, friends and the media. But an equally important reason to exercise every day is related to blood pressure, not waistline. As a physiologist who has studied exercise and health for over 20 years, I can tell you that exercise lowers blood pressure – and does so right away. Whether you go for a daily run or brisk walk, every time you finish exercising your blood pressure goes down, and stays down for many hours, which is good for your overall health. Here’s why.


Immediate drop in blood pressure occurs

The immediate blood pressure lowering effect of exercise is referred to as “post-exercise hypotension,” and many studies have shown that blood pressure declines 5 to 7 mmHg after every exercise session. The mechanisms responsible for lowering blood pressure immediately after exercise are not fully understood, but involve dilation of the blood vessels. Whatever the precise cause, this phenomenon is clearly beneficial.
During exercise the opposite occurs, blood pressure actually increases dramatically. Why? We are hardwired to exercise. When we exercise, our working muscles need oxygen-rich blood. Our brain signals the heart to increase blood flow and blood pressure rises. Systolic blood pressure (top number) can exceed 180 mmHg during hard exercise.
This sounds like a crazy-high number, and it would be if a reading like this were taken while seated, but it is not unusual during strenuous exercise. High blood pressure values during exercise are offset by the many low values recorded after exercise, to the benefit of the body.
Why worry about blood pressure? Simply put, high blood pressure (i.e., hypertension) kills. It is estimated that hypertension is a primary or contributing cause of death of more than 400,000 Americans annually. Estimates suggest that one billion people worldwide have hypertension. Here in the U.S., one-third of the population is hypertensive, and these numbers are projected to rise 7 percent by 2030. This is not just a concern for older adults - one estimate suggests that 19 percent of young adults have hypertension.
Hypertension increases the risk of heart disease, stroke and kidney disease. The societal costs of hypertension are astronomical. When you consider the cost of health care services, medications and missed days of work, estimates suggest that hypertension costs the U.S. US$46 billion per year. Often, there are no signs or symptoms of hypertension, which is why it is referred to as the “silent killer.” Even among adults who have been diagnosed with hypertension, nearly half do not have it under control despite taking medications. Needless to say, anything you can do to lower your blood pressure will lower your risk of disease.

Great news: You don’t have to spend hours on this

As my colleagues and I point out in the Mayo Clinic Proceedings, exercise guidelines for those with hypertension emphasize the importance of daily or near-daily exercise to lower blood pressure. While the guidelines focus on those diagnosed with hypertension, daily exercise can benefit everyone.
To some, daily exercise may seem onerous, but the good news is that the exercise need not be intense or lengthy – moderate intensity exercise such as brisk walking for 30 minutes will lead to reductions in blood pressure. There is even evidence that short exercise bouts throughout the day (e.g., 10 minutes, three times per day) can lower blood pressure.
The bottom line is that exercising every day (and obviously eating less) will help prevent holiday weight gain, but an equally important benefit of daily exercise is lower blood pressure.