Delayed onset muscle soreness (DOMS) is a specific type of discomfort in the muscles. It was previously believed that a “build up” of lactic acid in the muscles was responsible for DOMS. However, research now shows that lactic acid is removed from muscles within an hour after exercise.

More recent studies demonstrate that physical activity beyond the current ability of muscles to meet the demand result in a type of trauma to muscle fibers themselves. This overload creates “microtears” in the muscle fibers. It is characterized by increased
plasma enzyme activity.

DOMS typically increases during the first 24 hours after activity and peaks at about 48 hours. During that time, the muscle fibers then repair themselves by increasing in size and becoming stronger. As your body adapts to new levels of physical activity, you will notice that DOMS is less frequent, but your strength, stamina, and flexibility all are improving. To optimize the results of physical activity and reduce injury risk, take exceptional care to optimize your nutrition and rest.

As you become more physically activity, you will learn to attend to and differentiate the sensations you experience during and after physical activity. You can be assured that DOMS is not associated with long term muscle damage or reduction in function. However, do contact your health care provider immediately if you experience:

• DOMS that lasts longer than 48 hours
• discomfort or pain during activity that is either new or made worse by the activity
• continued discomfort in joints and/or bones

Let’s now look at resistance training, the part of the ACSM guidelines that cover muscle strengthening.

What it is…

…any exercise that increases muscle strength and stamina. Stronger muscles that can sustain activity are crucial for successful aging. Strength and stamina increase our resiliency in meeting the daily demands of life.

Recommendations for resistance Exercise (American College of Sports Medicine, 2011 Position Stand)

• Adults should train each major muscle group two or three days each week using a variety of exercises and equipment.
• Very light or light intensity is best for older persons or previously sedentary adults starting exercise.
• Two to four sets of each exercise will help adults improve strength and power.
• For each exercise, 8-12 repetitions improve strength and power, 10-15 repetitions improve strength in middle-age and older persons starting exercise, and 15-20 repetitions improve muscular endurance.
• Adults should wait at least 48 hours between resistance training sessions.

What are the major muscle groups?

All of you! Think about the parts of your body you use most frequently during the day:

• chest and shoulders to help you push things away from you and bring things toward you
• back so that you can sit, stand, and walk with reasonable postural control
• hips to keep you balanced as you propel yourself with your legs
• abdomen helps maintain appropriate relationship between upper and lower body, assist with breathing, and keep your “guts” in place
• arms and hands for manipulating objects
• legs and feet to move you easily from place to place

The importance of using “a variety of exercises and equipment”

Our bodies thrive on variety, and variety in exercise can keep physical activity fresh, even exciting. Our brains enjoy variety, too, and will develop new neurons whenever we are learning new things. Known as neurogenesis, this is an ongoing process that occurs throughout life

Even very light intensity strength training has benefits!

This is great news if you are not physically active now. It is all right to start with low intensity resistance training. The important thing is that you get active in a meaningful way so you can stay active and gain strength and stamina.

Sets and repetitions are variable to help you meet your strength goals.

The ACSM suggests you complete at least two full sets of resistance exercises with repetitions that are appropriate for your current status and for your personal goals.

• If your need is to develop strength and power, use heavier resistance with fewer repetitions.
• To improve muscle endurance, use lighter resistance and do more repetitions.
• New to strength training? Aim for 10-15 repetitions at a resistance where you can maintain your best form and technique.

Challenge:

In the next few days, visit a fitness facility or two. You will likely get a tour and certainly a sales pitch. Learn about programs and staff focusing on the specific needs of older adults. Ask for a complimentary pass for several days to try out the classes and meet with a responsive personal trainer. Hang out for a couple of hours to get a feel for how the staff and members behave. HAVE FUN!!

Next post covers muscle phenomenon known as “delayed onset muscle soreness”. After that follows details of developing a resistance training program.