It's Not Too Late For Cardiovascular Fitness

Endurance training had cardiovascular benefits even when starting after age 40

(RxWiki News) Once you pass a certain age, maintaining a healthy level of cardiovascular fitness may start to feel like a lost cause. But that may not actually be the case, says a new study.

This new study looked at the effect of endurance training, like running or cycling, on the hearts of healthy senior men.

The study found that regardless of whether these men started endurance training before age 30 or after age 40, that training seemed to show similar cardiovascular benefits in men over the age of 55.

"Talk to your doctor before starting a new exercise plan."

For this new study, which was led by David Matelot, of the Inserm 1099 unit in Rennes, France, the researchers wanted to see if starting endurance training at different ages changed how the training affected the heart.

To do so, these researchers looked at the cases of 40 men between the ages of 55 and 70 without any known cardiovascular risk factors. Of these men, 10 had never in their lives practiced cardiovascular endurance training for more than two hours a week.

The other 30 men had trained for more than five hours a week for more than five years in activities like cycling or running. Of these men with a history of endurance training, 16 started before they were 30 (at an average age of 22.1 years old) and 14 started after age 40 (at an average age of 47.9 years old).

Matelot and team looked at the participants' results from a variety of tests, including heart rate analyses, exercise tests and echocardiography tests, which give doctors insight into the size, shape and function of the heart.

When looking at the participants' average resting heart rates, the groups of men with a training history had similar rates — rates that were significantly slower than those of the men with no training history. The men who started training before age 30 had an average resting heart rate of 58.1 beats per minute (bpm), and the men who started after age 40 had an average of 60.6 bpm, while the men without training had an average of 69.7 bpm.

According to the Mayo Clinic, a normal resting heart rate range is typically anywhere from 60 to 100 bpm, but a lower rate is considered a sign of better cardiovascular fitness, with highly trained athletes potentially having rates of around 40 bpm.

When looking at the participants' maximal oxygen uptake (VO2 max), a measure of aerobic fitness, the researchers also found similar results in both training groups, but lower results in the untrained men. Those who started training before age 30 had an average VO2 max of 46.6 milliliters per minute per kilogram (ml/min/kg) and those who started after 40 had an average of 43.4 ml/min/kg, while those with no training had an average of 32.9 ml/min/kg.

According to the Fitness Institute of Texas at the University of Texas at Austin, an average VO2 max for men aged 60 and older is 31.8 ml/min/kg. A higher VO2 max represents better cardiovascular fitness.

When looking at the echocardiography tests, Matelot and team found some differences in the structure of the heart between those who had trained and those who had not. The left ventricle and both atria were larger in men who started training at any age than those who had not, and those without a history of training had thicker walls in the structure of the heart.

According to the National Institutes of Health (NIH), increased size and thickness in the structure of the heart can develop due to issues like high blood pressure and heart valve disease.

There was also evidence of diastolic dysfunction - a decline in the function of the heart's ventricles, which work to pump blood - in 44 percent of the men who started training before 30, 50 percent of the men who started training after 40 and 80 percent of the men who had never trained.

"Regardless of the age at which it has been started, relatively intensive endurance training presents the same benefits on heart and its regulation by autonomic nervous system in healthy senior men," wrote Matelot and team.

This study relied on a fairly small sample of participants. Further research is needed to confirm the findings.

The study was presented May 9 at EuroPRevent 2014, the European Society of Cardiology's annual conference. Studies presented at conferences are considered preliminary until published in a peer-reviewed journal.

No conflicts of interest were reported.

Review Date: 
May 7, 2014