Linking Lifting Weights to Living Longer
Can building our muscles help us live longer? New research has shown that yes. Researchers found that lifting weights is linked to lower death rates from all causes, except cancer. The British Journal of Sports Medicine published their findings online September 27, 2009.
Lead author Jessica Gorzelitz (PhD), a researcher at the National Cancer Institute's division of genetics and cancer epidemiology, is describing how older adults who exercised weightlifting had lower rates of mortality than those who didn't. She also explains that the risk was significantly lower for people who were not involved in aerobic exercise. The current U.S. Adult Physical Activity Guidelines are supported by these results, she says.
The current activity guidelines recommend some form of strength training
The current guidelines for physical activity recommend that adults engage in at least 150 minutes of moderate-intensity aerobic activity per week, and at minimum 75 minutes of vigorous activity every other week. This is commonly known as MVPA (moderately vigorous physical activity).
The guidelines also recommend that aerobic exercise be continued for at least two days. These strengthening exercises should include all major muscle groups including legs, hips and back as well as shoulders, arms, stomach, chest, shoulder, and elbows.
Cardio exercise is also called "cardio" and has been associated with numerous health benefits including lower mortality rates, improved blood sugar control, and a reduced risk of developing heart disease. The authors don't know if weight lifting might help to prolong life.
Nearly 44% of people reported lifting weights regularly. Researchers recruited men and women from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, which started in 1993 and included 154,897 participants aged 55-74 from 10 U.S. hospitals.
The final analysis included 99,713 participants. Participants were 53% women, while 3.3% of them were black. 1.4 percent Hispanic was 94%, and 3.9% were from other races.
At the beginning of the monitoring period, the average age was 71 and the average BMI was 27.8. According to the Centers for Disease Control and Prevention, a BMI between 18.5 and 24.9 is considered healthy and 25 to 29.9 considered to be overweight. A BMI greater than 30 is considered obese.
The participants were also asked whether they have exercised with weights during the past year and, if yes, how often. There were a variety of answers, ranging from one to many times per week.
In addition to asking about intensity and frequency of moderate- and vigorous-intensity physical activity, the questionnaire asked questions regarding the previous year. The questionnaire asked about moderate intensity, which was defined as activity that produces a slight sweat or increases your heart beat to moderately high levels. While vigorous activity is "activity that causes you to sweat or raises your heart rate and breathing to extremely high levels"
Based on the total weekly MVPA minutes, researchers divided them into 4 groups: 1. Inactive, 0 minutes; 2. Insufficient aerobic MVPA. 1 - 149 minutes. Sufficient 150 to 300 minutes of moderate or equivalent vigorous activity. Highly active, at least 301 minutes of moderate or equivalent vigorous activity.
Nearly one in four (23%) of individuals reported weight lifting, with 16 percent reporting that they regularly exercised between one to six times per week. A little over one third of people (32%) adhered to guidelines regarding physical activity. Eight percent exceeded these guidelines, meaning they exercised for more than five hours each week.
The lowest risk of death for people who lift and exercise weights
28477 people died during the 9.5-year follow up. The following links were found between aerobic exercise and weight lifting.
Both aerobic MVPA and weight exercise were associated with lower deaths from any cause. There was a 9 to 22 per cent lower death rate if you did not exercise with aerobic MVPA. The amount of weight that you used was also important. Aerobic MVPA had a lower death rate in people who did not lift any weights than those who said they didn't do MVPA or exercise with weights. The highest risk of death occurred for those who did both forms of exercise. Participants who exercised at least once a week and met the recommended daily levels of MVPA were 41-47 percent less likely to die than those who are physically inactive. The researchers were able to find similar results when controlling for multiple factors such as education, smoking, BMI and race, but not sex. Women had stronger associations with weight lifting and aerobic exercise than men.
The authors concluded that these findings support current recommendations for both cardio- and muscle-strengthening exercises.
How can lifting weights help people live longer?
Dr. Gorzelitz admits to some that people may wonder why weightlifting - even without doing aerobic exercise – could make people live longer.
Muscle strengthening exercises are associated with many benefits. They include strength enhancement and improved function. Although we are still studying the effects of weightlifting on metabolic systems, which may impact mortality risk, it is clear that such exercise has a positive effect on both body composition as well as other metabolic risk factors like blood pressure and inflammation markers, she said.
Cleveland Clinic says that muscle mass, or the quantity of muscle, can have an impact on metabolism. It takes more energy to build and maintain muscles than it does fat. People who are more muscular tend to burn more calories.
You may reap the benefits of strength training even if you do not exercise a lot.
Gorzelitz says these findings prove that weight lifting is an important part of your exercise routine for improved health and longer life expectancy, regardless of whether you are an aerobically active person.
Gorzelitz offers some suggestions for taking small steps to get you started if weightlifting intimidates you. Our results show that more is better than less, so it's OK to start slowly and build your confidence as you gain strength.
Researchers Hope to Find Out More About a Diverse Population
The authors acknowledged several limitations in the study. The study was observational and did not prove weightlifting or other physical activities lead to longer lives. This analysis was also based on participants' personal experiences with strength training, exercise, weight training, volumes (sets or repetitions), as well as details about how much time they had been using weights.
The study focused only on weights, but the authors note that there are other ways to strengthen muscles, including body weight exercises such as push-ups and squats, Pilates, and plyometric exercises such as tuck jumps and burpees.
Gorzelitz says future research will focus on more in-depth assessments of weight lifting beyond the duration and frequency per week. She says, "My aim is to reproduce these findings in more varied populations to ensure that results are broadly applicable, and this includes testing on clinical populations that might benefit such as survivors of cancer."
Gorzelitz states that as we gain more knowledge, our abilities to create safe and effective interventions for strengthening and aerobic exercises can be improved so that adults of all ages are able achieve the recommended levels of exercise in accordance with the Physical Activity Guidelines.