Exercise Keeps Us Young at Heart in More Ways Than One
New study identifies a prescriptive dose of exercise that remodels aging hearts.
Posted Jan 08, 2018
Heart disease is the number one cause of death in the United States for both men and women. CDC statistics show that approximately 610,000 people in the U.S. die of heart disease every year. This is the equivalent of one out of every four deaths.
Notably, the double whammy of sedentary lifestyle behaviors and low levels of physical fitness increase the risk of heart disease and heart failure. Despite these grim statistics, there is some good news. Even people in middle age—who have been living a sedentary life for decades—can reverse their risk of heart failure by kick-starting a fitness regime, according to a new study.
This paper, “Reversing the Cardiac Effects of Sedentary Aging in Middle Age—A Randomized Controlled Trial: Implications For Heart Failure Prevention,” was published today in the journal Circulation. This study was conducted by a team of researchers at the internationally renowned Institute for Exercise and Environmental Medicine in Dallas, Texas. IEEM is a collaboration between the University of Texas Southwestern Medical Center (UTSW) and Texas Health Presbyterian Hospital Dallas.
According to the IEEM researchers, men and women who began a robust fitness routine in middle age were able to reverse the damage of a sedentary lifestyle by improving the elasticity of their hearts. This prevented the risk of future heart failure.
At the outset of this two-year study, the researchers recruited 61 male and female participants between the ages 45 to 64. (Fifty-three participants completed the study.) All participants were randomly divided into two groups. One group received two years of supervised exercise training. The other cohort served as a control group that did not perform moderate-intensity aerobic exercise, high-intensity interval training (HIIT), or strength-training exercises.
There is one important caveat about this study: The amount of time and intensity of the exercise prescriptive could be daunting and/or unrealistic for many people. To reverse the signs of an aging heart, working out two to three times a week wasn't enough to remodel the heart. It appears that this heart-specific exercise regimen needs to be performed four to five times a week. Also, the exercise prescriptive used for this study should begin before age 65, when the heart still has substantial plasticity and can remodel itself.
That said, countless other studies have shown that much less exercise at lower intensities can provide a myriad of psychological and physical health benefits at any age. So, if this program is too much for you (or if you're over 65), please don't be discouraged to keep doing what you're doing regarding daily physical activity.
Remember: A recent study found that just 60 minutes of activity at any intensity per week (less than 10 minutes a day) can prevent future depression. For more on this, check out, "One Hour of Exercise Per Week Protects Against Depression."
How Does Exercise Reverse the Cardiac Effects of Sedentary Aging?
Previous research by UTSW cardiologists found that left ventricular (LV) stiffness is common among middle-aged men and women who are sedentary and out of shape. The goal of the latest study by IEEM was to see if a finely-tailored exercise routine could reduce LV stiffening. The results were promising: upwards of 25 percent of those in the exercise group showed significant improvement in LV elasticity and plasticity.
“Sedentary aging can lead to a stiffening of the muscle in the heart's left ventricle, the chamber that pumps oxygen-rich blood back out to the body,” senior author Benjamin Levine, founder and director of IEEM and professor of internal medicine at UTSW, said in a statement. "When the muscle stiffens, you get high pressure, and the heart chamber doesn't fill as well with blood. In its most severe form, blood can back up into the lungs. That's when heart failure develops."
The exercise regimen for this two-year study included at least four to five bouts of exercise per week (generally in 30-minute sessions) plus a warmup and cool-down. All of the workouts were individually tailored based on exercise tests and heart rate monitoring. Levine described the specifics of this exercise prescriptive in a statement:
- One or two of the 30-minute sessions were performed each week at a moderate intensity, meaning the participant would break a sweat, be a little short of breath, but still be able to carry on a conversation using the "talk test."
- One day was dedicated to an "endurance" session which lasted for 60 minutes and was also of moderate intensity.
- One or two of the weekly sessions included a high-intensity interval training (HIIT) 30-minute workout. During aerobic interval sessions, your heart rate generally tops 95 percent of peak rate for 4 minutes, with 3 minutes of recovery, repeated four times (a so-called "4 x 4"). Each interval session was followed by a recovery session performed at relatively low intensity.
- One or two weekly strength training sessions (using weights or strength-training machines) were included on a separate day, or after an endurance session.
Study participants built up to the above levels, beginning with three, 30-minute, moderate exercise sessions for the first 3 months. After 10 months of regular training, the two high-intensity aerobic interval training sessions were added to the program.
"Based on a series of studies performed by our team over the past 5 years, this 'dose' of exercise has become my prescription for life," Levine said. "I think people should be able to do this as part of their personal hygiene—just like brushing your teeth and taking a shower."
The authors sum up their findings in the study conclusion: “Regular exercise training may provide protection against the future risk of heart failure with a preserved ejection fraction by preventing the increase in cardiac stiffness attributable to sedentary aging.”
The exercise "Prescription for Life" used by Levine and colleagues from IEEM dovetails with my coaching recommendations in The Athlete’s Way (St. Martin's Press). For more specific tips on how to structure aerobic workouts of varying intensity, duration, and frequency—check out Chapter Six: The Cardio Prescriptive. Also, if you'd like advice on the basics of lifting weights and illustrations that show the gold-standard of a full-body strength training session, check out Chapter Seven: The Strength Program.
*As always, please use common sense and consult with your primary care physician before beginning any new exercise regimen.
Erin J. Howden, Satyam Sarma, Justin S. Lawley, Mildred Opondo, William Cornwell, Douglas Stoller, Marcus A. Urey, Beverley Adams-Huet, Benjamin D. Levine. "Reversing the Cardiac Effects of Sedentary Aging in Middle Age—A Randomized Controlled Trial: Implications For Heart Failure Prevention." Circulation (Originally published: January 8, 2018) DOI: 10.1161/CIRCULATIONAHA.117.030617
Laura F. DeFina, William L. Haskell, Benjamin L. Willis, Carolyn E. Barlow, Carrie E. Finley, Benjamin D. Levine, and Kenneth H. Cooper. "Physical Activity Versus Cardiorespiratory Fitness: Two (Partly) Distinct Components of Cardiovascular Health?" Progress in Cardiovascular Diseases (2015) DOI: 10.1016/j.pcad.2014.09.008
Paul S. Bhella, Jeffrey L. Hastings, Naoki Fujimoto, Shigeki Shibata, Graeme Carrick-Ranson, M. Dean Palmer, Kara N. Boyd, Beverley Adams-Huet, and Benjamin D. Levine. "Impact of Lifelong Exercise “Dose” on Left Ventricular Compliance and Distensibility." Journal of the American College of Cardiology (2014) DOI: 10.1016/j.jacc.2014.03.062