Many things change as we get older. First, our recall seems to leave us. We cannot remember where we put the car keys, our neighbor’s first name, or what on earth we came into the kitchen for.
Then it is our eyesight. We need to hold the menu or newspaper further and further away just to read it. And, God forbid, we don’t have adequate lighting!
Then there are the more serious changes that can occur. Stiff joints, shortness of breath, even decreased endurance.
But, before we get too melancholy, there’s good news. Eating a healthy, Mediterranean diet and getting consistent exercise can help to fend off many signs and symptoms of aging, such as those above.
Most importantly, there’s the effect that a good diet and adequate exercise has on your heart. By keeping your heart strong, you are more likely to keep your body in top working order.
While we know the basics of what to eat, exercise seems to stymie many people? Is aerobic exercise best? Strength training? Walking? Running?
According to recent research from the Scandinavian Cardiovascular Journal, aerobic interval training may be the way to go.
Determining Heart Health
According to researchers, there are five mechanisms that characterize the aging process of the heart:
- Increased thickening and/or scarring of the heart tissue
- Increased loss of heart muscle cells
- Loss of elasticity in the arteries
- Reduced metabolic capability of the heart muscle
- Decreased maximum heart rate
These processes can affect the way your heart actually functions, referring specifically to when your heart muscle is relaxed (diastolic), and when your heart is contracting (systolic). It is this constant contraction and relaxation that comprises your heartbeat.
As you age, the speed or velocity with which this contracting and relaxing occurs slows down. Additionally, the effort that your heart is able to endure beyond everyday circumstances (called myocardial or cardiac reserve) is also reduced as you age. This is even more obvious during times of exertion or exercise.
Interestingly, exercise itself has also been shown to improve this diastolic and systolic functioning of your heart. Plus, it has been found to improve cardiac reserve in both heart patients and healthy patients.
Given this, researchers questioned if exercise, namely aerobic interval training, could reduce normal age-related decline in diastolic and systolic cardiac function.
Exercise in an Older Population
To test this theory, researchers ran three consecutive studies:
1. They compared 11 seasoned male senior athletes (average age of 74) to 10 healthy but sedentary male seniors (age 70-plus), as well as 10 young, sedentary college males (average age of 23).
2. They tested the effects of short-term aerobic interval training on 16 sedentary seniors (both men and women).
3. They compared before and after scores of the sedentary male seniors to the seasoned older male athletes to determine short-term versus long-term training effects.
Researchers defined the seasoned athletes as men who have exercised at least five times a week for the last 25 years. In fact, these older men were still working out at least five times a week and the majority of them were competing at the top national or international level for their age group.
The aerobic interval training sessions for the sedentary seniors took place three times a week. Each session lasted 38 minutes and included:
1. A 10-minute warm-up at about 60 percent maximum heart rate
2. Four 4-minute intervals at 90 percent to 95 percent maximum heart rate with three minutes of active rest between each burst
- The exercise was done either walking or running uphill on a treadmill
- The “rest” periods were done at 60 percent to 70 percent maximum heart rate
- The entire set of four intervals with three minutes in between took 25 minutes
3. A three-minute cool down
The sedentary college students did not exercise and served as a control of sorts. They were used to represent examples of normal, young, non-exercising heart health baselines.
To establish these baselines, as well as monitor cardiac improvement, researchers tested all participants for the following biomarkers:
- Resting heart rate
- Blood pressure
- Blood volume in the left ventricle (lower chamber of the heart)
- Ejection fraction (amount of blood pumped out of the right ventricle and into the left ventricle with each beat of the heart)
- Stroke volume (the volume of blood pumped from a ventricle, usually the left ventricle)
Both ejection fraction and stroke volume are used to measure cardiac output, or how effectively and efficiently your heart is working.
Researchers tested the sedentary college students and the seasoned senior athletes at the start of the program, while the sedentary seniors (male and female) were tested at the start of the program and again 12 weeks later). They found that the healthy, sedentary seniors enjoyed significant reductions in both weight and BMI.
After the exercise regimen, the seniors also had a 12 percent reduction in systolic blood pressure (top number) and a 9 percent reduction in diastolic blood pressure (bottom number). Additionally, they increased their blood volume in the left ventricle by 17 percent overall, with senior males seeing a 22 percent increase.
Stroke volume also increased by 10 percent among the seniors who performed the training. Finally, seniors also improved diastolic function, as well as both systolic and diastolic cardiac reserve.
When it came to comparing the three groups, hoping to demonstrate the effect exercise had on the aging heart, researchers found the following:
1. At the start of the study, resting heart rate was 18 percent higher in sedentary senior men versus the college students.
2. At the start of the study, resting heart rate was significantly lower for athletic seniors than sedentary seniors.
3. There was no difference in resting heart rate between athletic seniors and sedentary students.
4. Exercise reduced resting heart rate of sedentary seniors by 10 beats per minute.
5. At baseline, sedentary seniors had higher blood pressure levels than both the senior athletes and the students.
6. Sedentary seniors had lower left ventricle volume than the students (likely due to atrophy of the heart muscle itself).
7. Sedentary seniors had lower systolic function than the students.
8. Athletic seniors had better left ventricle volume, as well as superior diastolic cardiac reserve, as compared to the sedentary college students.
Based on this, researchers concluded that short-term aerobic interval training significantly improved left ventricular diastolic function in sedentary seniors. In addition, short-term intensive training improved left ventricular diastolic and systolic function, as well as systolic function of the right ventricle.
All right, but what does all that mean for you?
Exercise Early and Often for Heart Health
To summarize at the most basic level, what the researchers found is that long-term exercise kept older hearts nearly as strong, and in same cases even stronger, than much younger men who didn’t exercise. They also found that just 12 weeks of interval training significantly improved heart function in otherwise sedentary seniors.
So, the takeaway is that the earlier in life you exercise and the more consistently you do that exercise, the better. But, if you have been off the treadmill bandwagon, it’s still not too late. You can enjoy great cardiac benefits in as little as three months.
Therefore, if you are already exercising regularly, keep it up! If you are slow to the exercise craze, start today. Aim for 30 to 60 minutes a week at least three days a week. And, as the study shows, alternating between high-intensity and lower intensity effort during the workout is best.
If you are not familiar with interval training, invest in a few personal training sessions until you get the idea. You can also try renting an exercise DVD that focuses on interval training. Whichever path you choose, just get moving.
 Molmen HE et al. Aerobic interval training compensates age related decline in cardiac function. Scand Cardiovas J. 2012 Jan 24. [Epub ahead of print.]
 Klausner SC and Schwartz AB. The aging heart. Clin Geriatr Med. 1985;1:119-41.
 Molmen HE et al.