Family and Consumer Sciences FSFCS33 Increasing Physical Activity as We Age Strength Training LaVona Traywick, Ph.D. Introduction Assistant Professor ­ Gerontology Strength training—also referred to as resistance training or weightlifting—is part of a comprehensive exercise routine which includes endurance or increased strength and muscle aerobic activity, balance or mass, strength training also stability training and flexibility or increases bone density. Strength stretching exercises. Strength training exercises have been training is when we work the shown to reduce the risk for skeletal muscles of our bodies numerous chronic diseases harder than they are used to, including diabetes, heart disease, usually through free weights, osteoporosis and arthritis. On top resistance bands/tubes or weight of that, strength training has been machines. Strength training shown to have many positive increases strength, anaerobic effects on psychological health endurance and muscle mass. The such as reduced depression, goal of strength training is to improved sleep and greater sense grow stronger. of well-being. Furthermore, As we age, muscle strength strength training is helpful in declines. Humans can lose up to maintaining a healthy weight. one-half of their strength and muscle mass between the ages of Exercise 25 and 80 years. Part of this Recommendations decline is due to the biology of aging; however, the other part of Adults and senior adults this decline is due to inactivity. should do strength training exer­ What is promising is that progres­ cises that work all major muscle sive strength training for adults groups (legs, hips, back, abdomen, and senior adults not only chest, shoulders and arms) two to prevents muscle loss but also three days a week with a “rest” increases strength and muscle day in between the strength mass, similar to what is observed training sessions. This “rest” day in young adults. Participating in does not mean to forgo doing the strength training has many other types of exercises—it is positive benefits for our health. specific for strength training. Arkansas Is Examples of strength training Our Campus Why Is Strength Training exercises include lifting or pushing Important? free weights, pulling resistance bands and using strength-training Visit our web site at: Strength training has many equipment at a fitness center or https://www.uaex.uada.edu important benefits. In addition to gym. In some cases, strength University of Arkansas, United States Department of Agriculture, and County Governments Cooperating training can include lifting your own body Progressive Strength Training weight, such as with push-ups or squats. The most common form of strength training Categories of Strength Training is weightlifting using free weights or various types of weight machines. In order to improve Strength training exercises can be classified strength, weight training must push the muscles into three categories: beyond what they are used to—called overload principal—by periodically increasing the amount • Isometric—sometimes referred to as of weight or resistance used in that particular “static”—is where no movement occurs; an exercise. This concept is referred to as Progres­ action in which the muscle develops tension, sive Resistance Exercise and is the basis for most but does not shorten. strength training programs. Example: Attempting to pick up the chair you How does progressive strength training work? are sitting in or standing with each hand on When you first begin, you should start exercising opposite sides of a doorway attempting to with weights that you can lift at least ten times push down the walls. with only moderate difficulty. If you cannot do at least 8 repetitions, the weight you are using is too • Isotonic—sometimes referred to as dynamic; heavy and you need to use a lighter weight. If you contractions in which a muscle shortens can do over 12 repetitions, the weight you are against a constant load or tension, resulting using is too light and you need to use a heavier in movement. weight. After two weeks of strength training, you should reassess the difficulty of each exercise with Example: Using free weights (such as your current level of weights. barbells and dumbbells) or commercial weight machines. Isotonic exercises also For example, you may have started doing the include variable-resistance exercises such as biceps curl with a 3-pound weight. By the end of using stretch bands and exercise tubes as the second week, the exercise has become too well as commercial devices. easy for you, and you should increase your weights to a 4- or 5-pound dumbbell. At the end • Isokinetic—the exertion of force at a constant of the fourth week, you once again reassess. You speed; action in which the rate of movement may stay with the 5-pound weight one more is constantly maintained through a specific week or you may move up to a 6- or 8-pound range of motion even though maximal force weight. A good way to check to see if you are is exerted. ready to increase your dumbbell weight or if you should stay the same is to do the exercise with Example: Performing the exercise on your current weight and count your repetitions. commercial isokinetic devices. The machine is If you can easily lift the current weight dumbbell programmed to move at a certain speed so it through the full range of motion and in proper will vary its resistance against you to main­ form more than 12 times, you should increase tain that speed. This means if you push your dumbbell weights by 1 to 3 pounds and see against the machine hard, it will give back a how the exercise feels at the new weight level. lot of resistance to maintain the speed at With the new weight, you should be able to have which it was told to go. correct form for at least 8 repetitions. Although all forms of strength training are When performing strength training exercises, beneficial, performing isotonic exercises using you should only use equipment intended for free weights (dumbbells and/or barbells) is exercise. There is an increased risk of injury and recommended over the other methods. Research improper form when using household items as studies have shown that, compared to other weights. It is also important to note that you will methods of weight training, free weights produce need different size weights for different exer­ greater strength gains during short-term train­ cises. For example, a person may be able to ing periods, provide greater movement abilities perform a wrist curl with a 3-pound weight, the and involve both balance and stabilizing factors. biceps curl with an 8-pound weight and the The disadvantages of free weights include the shoulder press with a 5-pound weight. possibility of injury (such as dropping the weight on your toe), needing a “spotter” for heavy Biology of Strength Training weights and learning the proper lifting tech­ As we age, muscle strength declines. Most of nique. That said, it is better to do some kind of this decline happens after the age of fifty. This strength training than nothing at all. loss of strength is mainly from inactivity—not using our muscles. Another part of the muscle Strength training not only increases our strength decline is due to the aging process. This muscle mass, it also increases our bone density. loss of strength due to aging actually occurs at Bones respond to strength training by increasing the motor neuron level. The motor neuron is what their bone density. The bone grows stronger or gives the message from your brain through the denser in response to the forces associated with central nervous system to the muscle telling it to the muscle contraction. As the muscles get contract and move. This decline in the motor stronger, the bone gets strong too. How does this neuron is a neurological change that occurs with work? Bone is made up of a configuration of bone aging. This is important to note because whatever fibers, blood vessels and lymphatics which is affects the motor neuron affects the muscle fibers called osteoid. Bone responds to stress (such as attached. So a decline in the motor neuron unit strength training) and disuse (as in our sedentary leads to a decrease in muscle fibers (both Type I lifestyles) by increasing the osteoid in areas that and Type II muscle fibers). The loss of muscle are subject to stress and reducing it in areas fibers from those individual motor neuron units where it is no longer needed. Increased bone results in less available force for a muscle density is called sclerosis. Sclerosis of the bone contraction when that motor neuron is stimu­ can result from strength training exercise. It is lated. Once the muscle contraction mechanism is important to note that bone adaptations impaired, there is a loss of strength and power. are exercise specific. For example, a lower body The good news is that regular, progressive exercise—such as a squat—will strengthen the strength training can reverse the loss of muscle leg bones but will not strengthen the bones in the strength due to the biology of aging. upper body. Sample Exercises Be sure to warm up your muscles before you begin strength training. (For more information about the warm-up, see FSFCS34, Stretching.) The number of times you perform the exercise is called the repetitions or reps. The number of times each group of repetitions is performed is called the set. For all the following exercises, strive for 2 sets of 10 repetitions. In other words, perform the exercise 10 times, rest for a minute, then do the exercise 10 more times. Note: When using dumbbells, do not work with two different size weights per hand.