Healthy people, healthy planet

Strength Training For Seniors: The Facts


Dr. Westcott
During the past several years, many studies have highlighted the health value of strength training for aging adults. Research at the University of Maryland has shown that strength training is effective for improving glucose metabolism 1, increasing bone mineral density2, and speeding up gastrointestinal transit3. Studies at Tufts University have demonstrated that strength exercise adds lean tissue 4, increases resting metabolism 5, and reduces arthritic discomfort6. Extensive work at the University of Florida has shown that strength training increases low back strength and alleviates low back pain 7.


From an athletic perspective, research reveals that strength training improves golf performance by increasing club head speed and driving power 8. Empirical evidence indicates that strength exercise may also enhance other physical activities s as tennis 9 and cycling 10.


While all of these health and performance factors are important, perhaps the most compelling concerns for most seniors are the three “B”s. These are bodyweight, body composition, and blood pressure. Generally speaking, senior men and women are concerned about gaining weight, getting soft, and experiencing elevated blood pressure. They have already discovered that dieting doesn’t produce permanent weight loss, and that walking is not very effective for firming muscles. Quite true. They are afraid to try strength training because they’ve heard that it will increase their blood pressure. Untrue.


Several small-scale studies have shown that strength exercise is effective for decreasing bodyweight11, increasing lean weight 12, and reducing resting blood pressure13. In addition, strength training results in a higher resting metabolic rate 14 and greater daily energy utilization 5.


But what specific changes can seniors expect from a basic program of strength exercise? We recently analyzed data on 1,132 men and women who completed the South Shore YMCA basic fitness program 15. All of the participants performed 25 minutes of strength exercise and 25 minutes of endurance exercise, two or three days per week for a period of eight weeks.


The strength training program included the following Nautilus exercises: (1)leg extension; (2) leg curl; (3) leg press; (4) chest cross; (5) chest press; (6) super pullover; (7) lateral raise; (8) biceps curl; (9) triceps extension; (10) low back; (11) abdominal; (12) neck flexion; and (13) neck extension. Each exercise was performed for one set of 8 to 12 repetitions, at a slow movement speed (2 seconds lifting and 4 seconds lowering), and through a full movement range. Resistance was increased by approximately five percent when 12 repetitions were completed.


The endurance training program involved treadmill walking and stationary cycling. Participants exercised at about 70 to 75 percent of their maximum heart rate, and progressively increased their training time to 25 minutes of continuous aerobic activity.


The basic fitness program was offered in a separate and carefully supervised exercise room. Classes were held almost every hour throughout the day, and typically had six participants with two instructors. All class members were assessed for bodyweight, body composition, fat weight, lean (muscle) weight, systolic blood pressure, and diastolic blood pressure before and after the two-month training period.


Bodyweight and Body Composition Changes


The 1,132 basic fitness program participants included 238 young adults (21 to 40 years), 552 middle-aged adults (41 to 60 years), and 341 senior adults (61 to 80 years). As shown in Table 1, all three age groups started the program with similar bodyweights (172.7 lbs. to 179.9 lbs.) and percent fat readings (25.6% to 27.2%).




Table 1. Changes in bodyweight and body composition for young, middle-aged and older program participants(N=1132).






























































Age Body Weight Pre (lbs.) Body Weight Post (lbs.) Body Weight Change (lbs.) Percent Fat
Pre (%)
Percent Fat
Post (%)
Percent Fat Change (%) Fat Weight Pre (lbs.) Fat Weight Post (lbs.) Fat Weight Change (lbs.) Lean Weight Pre (lbs.) Lean Weight Post (lbs.) Lean Weight Change (lbs.)
21-40 years
(N=238)
176.5 173.9 -2.6 27.2 24.9 -2.3 49.1 44.2 -4.9 127.4 129.7 +2.3
41-60 years (N=553) 179.9 177.9 -2.0 27.0 24.9 -2.1 48.9 44.5 -4.4 130.8 133.1 +2.3
61-80 years (N=341) 172.7 171.0 -1.7 25.6 23.6 -2.0 44.7 40.6 -4.1 128.0 130.4 +2.4




The bodyweight and body composition changes were comparable for the young, middle-aged and senior adults. As presented in Table 1, the 21 to 40 year olds lowered their bodyweight by 2.6 pounds and their percent fat by 2.3%. The 41 to 60 year olds decreased their bodyweight by 2.0 pounds and their percent fat by 2.1%. The 61 to 80 year olds reduced their bodyweight by 1.7 pounds and their percent fat by 2.0%.


Changes in fat weight and lean weight were also similar for the three age groups. The 21 to 40 year olds lost 4.9 pounds of fat weight and added 2.3 pounds of lean weight. The 41 to 60 year olds lost 4.4 pounds of fat weight and added 2.3 pounds of lean weight. The 61 to 80 year olds lost 4.1 pounds of fat weight and added 2.4 pounds of lean weight, for a 6.5 pound change in their body composition (see Table 1).


These findings indicate that senior men and women improve their bodyweight and body composition about the same as younger adults in response to a basic program of strength and endurance exercise. It is interesting to note that the seniors developed lean (muscle) tissue at the same rate as the other program participants. Replacing muscle is essential for seniors, because sedentary individuals lose over five pounds of lean tissue every decade of adult life 16. By adding 2.4 pounds of muscle, the seniors in this study reversed almost five years of the aging process after just two months of strength training.


Blood Pressure Changes


All three age groups began the basic fitness program with similar diastolic blood pressure readings (76.1 mm Hg to 80.1 mm Hg). However, the average systolic blood pressure for the 61 to 80 year olds was considerably higher (143.1 mm Hg) than for the 41 to 60 year olds (127.9 mm Hg) and the 21 to 40 year olds (121.2 mm Hg).




Table 2. Changes in resting blood pressure for young, middle-aged and older program participants(N=785).


































Age Systolic BP Pre (mm Hg) Systolic BP Post (mm Hg) Systolic BP Change
(mm Hg)
Diastolic BP Pre (mm Hg) Diastolic BP Post (mm Hg) Diastolic BP Change (mm Hg)
21-40 years
(N=144)
121.2 116.7 -4.5 76.1 72.9 -3.2
41-60 years (N=375) 127.9 125.4 -2.5 79.0 76.6 -2.4
61-80 years (N=266) 143.1 136.9 -6.2 80.1 76.4 -3.7




As presented in Table 2, all three age groups lowered their resting blood pressures as a result of the eight week exercise program. However, the seniors experienced the greatest improvement, with a 3.7 mm Hg decrease in diastolic blood pressure and a 6.2 mm Hg reduction in systolic blood pressure.


The change in systolic blood pressure was particularly important to the senior participants because they began the study above the hypertensive level (140 mm Hg), but ended within the normal range.


Discussion of Findings


The results of this relatively large research study should be encouraging news for senior men and women. Consider the following key findings for the 341 older adults who completed the eight week basic fitness program.


1. Seniors can safely participate in a well-designed and carefully-supervised program of strength exercise. There were no injuries among the senior subjects in this study. Of course, all participants should have their physician’s approval before beginning an exercise program.


2. Seniors can improve their body composition. The seniors in this exercise program reduced their percent fat by 2.0% after just two months of training. This was similar to the body composition improvements attained by the younger adults.


3. Seniors can decrease their fat weight. Like the younger program participants, the senior subjects lost more than four pounds of fat weight during the eight week training period.


4. Seniors can increase their lean (muscle) weight. The seniors in this study added 2.4 pounds of lean weight after two months of training. In the important area of muscle replacement, the senior men and women did just as well as the young and middle-aged adults.


5. Seniors can reduce their resting blood pressure. Following eight weeks of regular exercise, the senior subjects experienced a 3.7 mm Hg drop in their diastolic blood pressure and a 6.2 mm Hg drop in their diastolic blood pressure. These resting blood pressure decreases were greater than those of the younger program participants.


6. Seniors can develop physically active lifestyles, even after years of sedentary behavior. Over 90 percent of the senior program participants continued to exercise after the completion of the study. They were highly satisfied with the results of the eight-week exercise program and committed themselves to keep up their training efforts.


In summary, seniors have much to gain from regular strength training, particularly as part of a supervised exercise program. The senior men and women in this study reported looking, feeling and functioning better, which is consistent with their recorded improvements in bodyweight, body composition, and resting blood pressure. It appears that an hour of exercise, two or three days a week is one of the best investments seniors can make for their health and fitness.


Wayne L. Westcott, Ph.D., is fitness research director at the South Shore YMCA in Quincy, MA. and author of the new Nautilus book, Building Strength and Stamina.




References


1. Hurley, B. (1994). Does strength training improve health status? Strength and Conditioning Journal, 16: 7-13.


2. Menkes, A., Mazel, S., Redmond, R. et al. (1993). Strength training increases bone mineral density and bone remodeling in middle-aged and older men. Journal of Applied Physiology, 74: 2478-2484.


3.Koffler, K., Menkes, A., Redmond, W. et al. (1992). Strength training accelerates gastrointestinal transit in middle-aged and older men. Medicine and Science in Sports and Exercise, 24: 415-419.


4. Frontera, W., Meredith, C., O’Reilly, K. et al. (1988). Strength conditioning in older men: skeletal muscle hypertrophy and improved function.Journal of Applied Physiology. 64 (3): 1038-1044.


5. Campbell, W., Crim, M., Young, V. and Evans, W. (1994). Increased energy requirements and changes in body composition with resistance training in older adults. American Journal of Clinical Nutrition, 60: 167-175.


6. Tufts University ëiet and Nutrition Letter. (1994). Never too late to build up your muscle. 12: 6-7 (September).


7. Risch, S., Nowell, N., Pollock, M. et al. (1993). Lumbar strengthening in chronic low back pain patients. Spine, 18: 232-238.


8. Westcott, W. (1995). Pumping irons. Nautilus, 17-19, Spring.


9. Westcott, W. (1995). Tennis: Serve up your best performance. Nautilus, 41-43, Spring.


10. Westcott, W. (1994). Cycling: Pedal past winter’s obstacles. Nautilus, 31-33, Winter.


11. Darden, E. (1987). The Nautilus Diet. Boston: Little, Brown and Company.


12. Westcott, W. (1993). Weight gain and weight loss: Reality and recommendations. Nautilus, 8-9, Winter.


13. Harris, K. and Holly R. (1987). Physiological response to circuit weight training in borderline hypertensive subjects. Medicine and Science in Sports and Exercise, 19: 246-252.


14. Pratley, R., Nicklas, B., Rubin, M. et al. (1994). Strength training increases resting metabolic rate and norepinephrine levels in healthy 50 to 65 year old men. Journal of Applied Physiology, 76: 133-137.


15. Westcott, W. (1996). How adults and seniors respond to a basic exercise program. IDEA Today. (in press).


16. Evans, W. and Rosenberg, I. (1992). Biomarkers: The 10 determinants of aging you can control. New York: Simon and Schuster.

Wayne L. Westcott PhD Written by Wayne L. Westcott PhD