Once adults pass their physical prime in their teens and 20’s, they lose an average of 10 ounces of lean body mass per year. On average, a person will lose approximately 40 to 50 percent of muscle mass, and 50 percent of muscle strength from age 30 to age 70. Strength training is recommended to counteract this loss of muscle.
But, recently, experts have identified power training as a potentially more effective method of improving function than traditional high-intensity strength training. Because of the preferential atrophy of type II (fast-twitch) muscle fibers that occurs with advancing age, the remaining muscle mass is not only smaller and weaker, but slower as well. This has a dramatic effect on potential power generation. In fact, the power output of type II fibers is approximately four times that of type I (slow-twitch) fibers.
How is power training defined when we are using the term in association with strength training and older adults? We might also call it explosive resistance training, or high-velocity training, where the concentric phase is performed “as fast as possible.” Muscle power is the product of force and velocity (force x velocity).
However, take careful note that experts have stressed the importance of performing resistance exercises in a slow, controlled manner is to avoid momentum. This is a problem that is inherent to gravity-based equipment such as dumbbells, barbells and weight stacks. When a weight is moving at a higher velocity, it takes more effort to stop the weight. This presents a risky situation for the musculoskeletal system in older adults.
Considering momentum, pneumatic equipment, elastic bands, body weight and medicine balls are good choices to use in a power-training program for older adults.
With pneumatic equipment, momentum is never an issue, because gravity is not involved in the resistance. It does not matter how fast or slow a person performs the movement; momentum remains close to zero.
Elastic bands are good for power training because as elastic is stretched, the resistance increases slightly, but the resistance curve stays the same at all movement speeds, so again momentum is not an issue.
Body weight allows for real-life, functional movements, such as stair climbing and rising from a chair. (Although having someone climb a flight of stairs as quickly as they can might not be a good idea for a number of reasons! Step ups would be a better choice.) For extra resistance, external weights can be added quite easily. Weight vests, weight belts, or just holding dumbbells can safely and effectively increase resistance for many older adults. In addition, these movements require more dynamic balance, so there may be additional benefits associated with this form of training.
And finally, medicine balls are a good option because the weighted ball is released at the end of the fast movement (throw) so that the momentum created does not stress the joints.
A sensible place to start is to incorporate power training into an existing strength-training program (using equipment appropriate for power training) at intensity somewhere between 40 and 70 percent of 1RM, and instruct the client to perform the concentric phase “as fast as possible”, while maintaining proper form. Consider your client’s current level of fitness and any joint problems as you design his/her program. Be careful not to overdo if you are adding more sets or exercises into an existing program to incorporate power training.
About the Author
Tammy Petersen, B.S., M.S.E., is the Managing Partner for the American Academy of Health and Fitness. She has written two books on adult fitness and designed corresponding training programs. Tammy’s educational background includes Bachelor of Science degrees in marketing and economics from Pittsburg State University, Pittsburg, Kansas. She holds a Master of Science in Education in the area of health and fitness, with an emphasis in geriatrics, from the University of Kansas, Lawrence, Kansas.