The new year has arrived and with it our annual resolution, "that this will be the year that I get in shape and shed a few pounds." This is an admirable aspiration and even more admirable if carried out consistently over the new year. In the paragraphs below I wish to share with you the positive effects of a regular and challenging exercise routine.
Exercise Lowers The Risk of Cardiovascular Disease
Most of us take the above statement as a truism. Regular exercise is not only beneficial in lowering the risk of developing cardiovascular disease but also in managing cardiovascular disease that is already present. Exercise that raises one's heart rate to one's age adjusted target heart rate and keeps it there for 20 to 30 minutes sets into motion a number of physiological changes that over time lead to this reduction in heart disease. The forcful contraction of the heart muscle along with the increased blood flow and pressure in the peripheral arteries leads to a resetting of the autonomic nervous system. This leads to changes in the resting state such as a lower resting heart rate, lower blood pressure, and a more variable heart rate. These are all associated with a decreased risk of cardiovascular disease. In addition, this regular exercise decreases inflammation that is measured by blood borne markers such a C-reactive Protein (CRP) and IL-6. Inflammation is a critical component of the development of arterial plaque. The most significant changes in inflammatory markers are seen after 12 months of regualar exercise.
Exercise Lowers the Risk of Chronic Diseases
Regular exercise as described above has been associated with a reduction in:
- early death
- type II diabetes
- high blood pressure
- adverse lipid profile
- metabolic syndrome
- colon and breast cancer
When formally sedentary people begin an exercise program as described above and continued for a period of 6 months or more, their CRP levels dropped by about 30% or roughly the equivalent of the amount decreased by a statin drug. There was also modest evidence for lower rates of hip fractures and reduced bone density.
Exercise Helps Reduce the Symptoms of Depression
One study found that 16 weeks of aerobic exercise was as effective in reducing the symptoms of depression as treatement with the antidepressant Zoloft. Both groups had a greater than 60% response rate i.e., a 50% or greater reduction in baseline symptoms. The Zoloft group responded faster but the exercise group had a more enduring effect with less likelihood of relapse. Exercise reduces sadness and limits depressive symptoms even in people who are not suffering from major depression.
Exercise Helps Reduce Anxiety
Exercise not only helps reduce the symptoms associated with generalized anxiety disorder and panic disorder but also reduces symptoms in people with "anxiety-sensitivity". People with anxiety-sensitivity tend to over-interpret and catastrophize physical sensations such as a rapid heart beat, sweating, and rapid breathing. All of these occur during vigorous physical exercise. Over time the person exercising learns that these sensations are not life-threatening and the catastrophizing thoughts get extinguished.
Exercise Improves Brain Functioning and Cognition
Aerobic exercise improves cognitive functions such as attention, planning, decision making, inhibition, and memory. These improvements may be accomplished by increasing the size of the hippocampus, increasing the levels of BDNF and increaseing the volume of the prefrontal cortex,, among other changes. Exercise in midlife has been associated with a decreased risk of developing dementia and Alzheimer's disease. Exercise may slow age related memory decline.
Building Physical Fitness Habits
Now that you know the benefits of regular aerobic exercise, I am sure you are ready to get started on a regular regimen of physical training. The first question is what is an appropriate "dose" of exercise. In 2008 the Department of Health and Human Services recommended that on a weekly basis each person engage in: 2 hours and 30 minutes of moderate intensity exercise such a walking briskly (not strolling but walking with intensity and purpose), or 1 hour and 15 minutes of intense aerobic exercise such as jogging or swimming laps as well as 2 days of muscle strengthening exercises. Daily calisthenic routines for conditioning may be found by entering the search terms "Air Force 5BX" or "Army Daily Dozen". Drs. Southwick and Charney suggest that a physical fitness routine should incorporate the following elements:
1, Learn as much as you can about physical fitness and the benefits for your health.
2. If you have medical conditions or are concerned about the stress of exercise on your health, consult a physician before starting a vigorous exercise routine.
3. Try different exercise routines.
4. Set well-defined goals and monitor these goals to stay on task.
5. Consider using a trainer or coach. At the least, utilize and accountability partner.
6. Reward yourself as your goas are met.
7. Gradually increase the intensity of your cardiovasular and strength training. Remember, if it doesn't challenge you, it will not change you.
8. After each workout, allow your body to recover.
9. Practice healthy eating and sleep habits (more on this in a later blog). For the time being remember: YOU CAN'T EXERCISE YOUR WAY OUT OF BAD EATING HABITS.
10. Focus on the positive feelings associated with your exercise, e.g., increased energy, a "good" muscle soreness, better sleep.
11. Try to reach the point where being physically fit is an intergral part of your definition of yourself.
Southwick, SM, Charney, DS, Resilience, The Science of Mastering Life's Greatest Challenges. Cambridge Univerisity Press. 2012