March 18, 2005 -- It's never too late to benefit from exercise, a new study confirms.
Regular exercise is universally recommended as part of a healthy lifestyle. It's repeatedly been shown to help hearts, challenge muscles, improve mood, lower stress, and burn calories. Weight-bearing exercise can also build stronger bones, which helps prevent osteoporosis.
But what if you've been a little slack about exercise -- or downright sedentary? Does your window of opportunity slide shut as the years gather? If you haven't laced up your sneakers in decades, should you just skip it and leave working out to the young?
Absolutely not, say Canadian researchers. Exercise can help people well into their golden years, they say.
No matter how many candles are on your birthday cake -- or how long you sat on the sidelines -- it's to your advantage to get moving to the best of your ability, the study suggests.
A decade of data backs the Canadian study. That's how long researchers monitored two groups of adults aged 55-75, watching for changes in fitness levels, heart disease risk factors, and other health problems.
When the study started, all participants were sedentary but healthy. Fitness and medical tests showed that they were roughly in the same shape. However, there was one key difference among them -- initiative.
Some adults took it upon themselves to contact the Canadian Center for Activity and Aging. They asked to sign up for a supervised exercise program. Those adults (266 people) hadn't been ordered to do so by a doctor; it was their personal choice, not part of rehabilitation.
The other 420 participants were randomly chosen from the same community. They hadn't voiced any interest in a formal exercise program. The researchers used them as a comparison group. Those adults were free to be as active as they wanted, but they weren't part of the structured exercise group.
The bar was set high for the exercise group. They attended three weekly aerobic sessions per week, jogging or walking for 30-45 minutes each time. The workouts were vigorous.
Participants were expected to make it to at least 80% of the available sessions. The proportion of participants meeting that standard for at least eight out of 10 years was "very high," say the researchers.
At follow-up, 161 active and 136 sedentary people were studied. There was no difference in drop-outs between the groups, say the researchers. Most of the exercise group met their criteria.
That's rare. "In our experience and supported in the literature, retention and compliance with these programs is difficult over the long term," they write, calling for more work to try to change that.
Some people in the comparison group (8%) said they had exercised during the study. That was fine with the researchers; they weren't about to discourage anyone from working out. However, those adults didn't exercise for more than 18 consecutive months, and none said they were following a specific training plan or guidelines.
The exercise group fared best across the board. Their gains included:
- Higher fitness level. A small increase in fitness was seen in the exercise group, compared with a 13% drop in that of the sedentary group.
- Lower prevalence of risk factors linked to heart disease. Metabolic syndrome was seen in 11% of the exercise group, compared to 28% of the sedentary group after 10 years. Metabolic syndrome is a group of risk factors that increase the risk of heart disease and can lead to type 2 diabetes. The risks include excess body fat (especially around the waist), high blood fat (triglycerides), high blood pressure, and low HDL "good" cholesterol.
- Fewer signs and symptoms of heart disease during exercise.
- Fewer illnesses besides heart disease (comorbid conditions).
- Increase in HDL "good" cholesterol. A 9% increase in HDL occurred in the exercise group, compared with an 18% drop in the sedentary group.
The numbers of participants who died of heart problems or entered a nursing home during the study were very small in both groups, but the active group had a slight edge.
Seven exercise participants entered a nursing home, compared with 16 from the sedentary group.
Four deaths in the exercise group stemmed from the heart, compared with six in the sedentary group.
Like exercise, diet can make a big difference in health. But the study didn't track how participants ate. No one knew what the adults were putting on their plates.
It's also possible that because the exercise group wanted to work out instead of being told to, they might be a bit different from other people. The researchers say they tried to take that into account, but that wasn't their main focus.
"It was not the objective of this study to test the multifaceted issues of exercise adoption and maintenance in the community, but rather to determine how older individuals who self-selected participation in an exercise training program differed in terms of metabolic risk from those who did not," write Robert Petrella, MD, PhD, and colleagues.
Their study appears in the March issue of Diabetes Care.