Strength Training for Older Adults

by David E. Verrill, M.S., R.C.E.P., FAACVPR

Strength training has become a very popular form of exercise for adults of all ages. This mode of exercise is especially important for older adults, as maintaining the strength to participate in vocational and recreational activities is imperative for this population. Studies have shown that this form of training is highly effective in improving strength, balance, functional capacity and bone density in geriatric populations (Fiatarone et al., 1990). Greater lean body mass and bone mineral content may reduce the incidence of osteoporosis, as well as complications associated with accidental falls in older adults (Brown et al., 1990; Hurley, 1995). Resistance training also enables elderly individuals to perform activities of daily living with greater ease and counteracts the muscle weakness and frailty that is often seen in the very old. An appropriate level of muscular fitness is integral in ensuring that older individuals spend their latter years in a dignified, self-sufficient manner. Moreover, resistive training improves carbohydrate metabolism through the development of lean body mass, which has a positive overall effect on basal metabolism. The effect of this form of exercise on blood lipid values in middle-aged to older participants is still inconclusive.

With age often comes disease progression. Resistive exercise training has been shown to be especially beneficial for older adults who have cardiovascular disease or for those who are at risk for developing metabolic or cardiovascular complications (Verrill and Ribisl, 1996). Further research is necessary to assess the benefits of this form of exercise training for older individuals with cancer, pulmonary disease, organ transplant or osteoarthritis. However, it is likely that structured resistive exercise will benefit these populations as well.

Modality

Because muscle strains and stress fractures are common in older adults who participate in exercise programs, the resistive exercise modality should not impose a significant orthopedic stress on the muscles and joints. In addition, the modality should be accessible, convenient and enjoyable for the participant, as each of these factors is directly related to adherence and compliance. A new strength training participant will be less likely to continue if they find the activity too stressful, uncomfortable or boring.

Resistive modalities range from weighted bags to expensive machines. Many new devices are available on the market to help older participants achieve the positive benefits of resistive training, and the list continues to grow as newer, less expensive devices reach the market. However, the potential buyer should be wary of the machines seen frequently in television infomercials, as some of these could break easily or be potentially harmful with improper use. Machine weights, free weights, hand weights, cuff or ankle weights, squeeze balls, and elastic bands or tubes are common modalities that may be used individually, or combined in a circuit to exercise all major muscle groups.

Each modality has its advantages and disadvantages. Given a choice, the older participant should use machine weights to train, as opposed to free weights. Machines usually require less skill to use, protect the back by stabilizing the user's body position, and allow the user to start with lower resistances and increase resistance in smaller increments. In addition, machine weights cannot be dropped, and they make it easier to control the exercise range of motion (Verrill and Ribisl, 1996).

Performing non-sustained, isometric motions with resistive apparatus, either with the participant stationary or walking (e.g., walking with an elastic tube), may be suitable exercise for properly screened older adults. This type of training may better prepare the individual for performing common activities of daily living, such as carrying grocery bags or pushing a lawn mower.

Duration

Older adults should complete a total body resistive training session within 20 to 30 minutes (American College of Sports Medicine [ACSM], 1995). Resistive exercise sessions lasting longer than 60 minutes may have a detrimental effect on exercise adherence. For older adults, there is no significant advantage to additional sets or longer sessions, as significant strength gains can be achieved in these individuals with fewer sets and lighter resistance loads. Longer sessions have been associated with greater dropout rates, smaller additional gains in strength, increased fatigue and potentially increased risk of musculoskeletal injuries (Gordon et al., 1995; Pollock et al., 1991).

Intensity

The intensity of resistive exercise includes variables such as the number of sets, number of repetitions, amount of resistance and volume of training. One set of eight to 10 exercises that trains the major muscle groups (e.g., quadriceps, hamstrings, pectorals, abdominals) has been recommended for older participants (ACSM, 1995). To determine resistive training load, various techniques have been used in older adults. The one repetition maximum (1 RM), or maximal voluntary contraction technique, has been used successfully in middle-aged to older adults without significant injuries (Gordon et al., 1995; Shaw et al., 1995). However, this technique may cause knee and shoulder injuries in participants over 70 years of age (Pollock et al., 1991). If this technique is used, the patient should be thoroughly screened for cardiopulmonary and orthopedic limitations.

A better technique to determine the proper training resistive load may be an acclimation technique, in which the participant starts with the lightest weight on each resistive device. The workload is then gradually increased to higher workloads every one to two weeks. This technique puts less initial stress on the musculoskeletal system, facilitates better orientation and may allow for a better resistive exercise prescription for the older adult. Ultimately, resistive exercise training should consist of one set of eight repetitions to 20 repetitions at a level of 40% to 60% of their 1 RM, or a perceived exertion rating of 12 to 14 (somewhat hard) on the Borg category perceived exertion scale (Borg, 1982).

Frequency

There has been much debate on the optimal training frequency for older adults. Two structured strength training sessions per week are the minimum number required to produce positive physiological adaptations. Three sessions per week performed on nonconsecutive days may be ideal for the older participant. However, simple low-level exercises performed with elastic bands or hand weights may be performed daily. These sessions should be brief (five minutes to 10 minutes) and may be performed more than once each day. For example, the elderly adult could perform upper body exercises with elastic bands in a chair while watching television, both in the morning and evening.

Progression

The older participant needs to slowly increase the intensity of training over time to maximize strength development and health gains. For the first six to eight weeks, minimal resistance should be used to allow for adaptations of the connective tissue elements (e.g., 30% to 40% of 1 RM). As the training effect occurs, progressive overload should be incurred by first increasing the number of repetitions, then by increasing the resistance. One should initially use a resistance that can be performed at least eight times. If machines are used, the increase in resistance should not be more than 5 lb for the upper body and 10 lb for the lower body per session. When returning from a layoff, the older participant should start back with resistances <50% of the intensity at which they were previously training, then gradually increase the resistance to their previous level.

Instruction and Safety

Proper instruction in resistive exercise techniques is crucial to assure that the participant performs the exercise in a safe and mechanically efficient manner, with low risk of musculoskeletal injury or cardiopulmonary complications. The Table lists basic resistive training instructions for older participants. The first several resistive training sessions should be closely supervised and monitored by the health care professional sensitive to the needs and capabilities of the participant. Readable safety instructions in large print, with diagrams, should be posted in the resistive exercise area in a fitness facility. An ACSM-certified exercise specialist or clinical exercise physiologist, physical therapist, athletic trainer or personal fitness trainer familiar with geriatric populations should thoroughly orient the older adult on each modality or piece of equipment. This initial orientation is important, as those properly trained on each piece of equipment learn to perform the exercise safely and efficiently. Ample time should be allowed for questions, testing and practice on each modality during the initial exercise session. A complete description of the mechanical function of each piece of apparatus, correct body position and clear warnings about the risk of improper use should be provided by the supervising health professional. Whatever resistive mode is selected, the participant should be warned against breath-holding or prolonged isometric contractions, as these may invoke Valsalva's maneuver. The participant should also report any symptoms of pain or intolerance with each piece of apparatus.

Conclusion

With proper instruction and supervision, older men and women can safely perform resistive exercise training to achieve a number of important health benefits. Your older patient should be strongly encouraged to participate in some form of daily resistive exercise to promote strength development, increase bone mineral content, improve functional capacity, and facilitate positive metabolic processes. The result will help your patients gain self-confidence, develop self-efficacy and have a better overall outlook on daily living.

Mr. Verrill is the coordinator of the Presbyterian Hospital Pulmonary Rehabilitation Program in Charlotte, N.C. He is certified as an American College of Sports Medicine exercise specialist, program director and clinical exercise physiologist.

References

American College of Sports Medicine (1995), ACSM's Guidelines for Exercise Testing and Prescription, 5th ed. Baltimore: Williams & Wilkins.

Borg GA (1982), Psychophysical base of perceived exertion. Med Sci Sports Exerc 14(5):377-381.

Brown AB, McCartney N, Sale DG (1990), Positive adaptations to weight-lifting training in the elderly. J Appl Physiol 69(5):1725-1733.

Fiatarone MA, Marks EC, Ryan ND et al. (1990), High-intensity strength training in nonagenarians. Effects on skeletal muscle. JAMA 263(22):3029-3034.

Gordon NF, Kohl HW 3rd, Pollock ML et al. (1995), Cardiovascular safety of maximal strength testing in healthy adults. Am J Cardiol 76(11):851-853.

Hurley BF (1995), Strength training in the elderly to enhance health status. Medicine, Exercise, Nutrition, and Health 4(1):217-229.

Pollock ML, Carroll JF, Graves JE et al. (1991), Injuries and adherence to walk/jog and resistance training programs in the elderly. Med Sci Sports Exerc 23(10):1194-1200.

Shaw CE, McCully KK, Posner JD (1995), Injuries during the one repetition maximum assessment in the elderly. J Cardiopulm Rehabil 15(4):283-287.