As a follow-up to my last article, I’m going to focus on an in-depth look at strength training. If you haven’t read my last couple of articles regarding fitness as it helps with longevity, and healthspan, I recommend you do so now.
Note: this article was written for the general public for the promotion of overall fitness and a healthy lifestyle,
not for competitive strength or power training
Skeletal muscle strength training, is often times overlooked in fitness, even though it is a path to a long functional and healthy life. This tends to be truer for women because they often did not grow up with the idea of how important it is, or they have a fear of getting big bulky muscles. It is well known that the latter is an unjustified fear for women. With this article I’m going to dig down into the latest research and protocols surrounding muscular strength training.
Why Muscle Mass and Strength Matter for Healthspan
Research has repeatedly shown that in humans, muscle strength and/or muscle mass is considered one of the greatest predictors of a healthy lifespan. Here are the reasons why.
- Metabolic Health Benefits of Muscle. The benefits of muscle are well established and clear in the research. Skeletal muscle is the major site for glucose uptake. Having more muscle helps buffer blood sugar levels which helps decrease the risk of type 2 diabetes, heart disease, dementia, cancer and even weight gain. The bottom line is that having muscle strength and mass increases your ability to dispose of glucose and help prevent insulin resistance. Insulin resistance is when cells lose their ability to respond to insulin therefore leading to high blood sugar and diabetes. However, if you have good muscle strength and mass the insulin receptors in muscles are far more sensitive for the needed glucose uptake.
- Inflammation and Myokines. Skeletal muscles are endocrine organs in which they secrete signaling molecules called myokines. Myokines work to reduce chronic inflammation in the body and influences metabolism and the immune system. These Myokines also help protect against insulin resistance, hyperlipidemia, type 2 diabetes and cancer.
- Muscle is a Reservoir for Protein. Muscle is the only meaningful protein storage system in the body. With protein being stored in muscle it preserves muscle strength and mass. Protein synthesis declines with age. So, strength training and protein intake is not only necessary for many metabolic processes, it is essential for the repair of the body during periods of stress such as illness or injury.
- Movement, Mobility and Aging. It is well understood how important movement and activity is as we age. We know that muscle strength peaks in your 30’s and early 40’s (power peaks at an earlier age) with declines in strength after that. After your peak, muscle strength declines 1-2% a year and even more if a health event occurs. Staying injury free and training is important to decrease any strength declines. Research shows that after the age of 70 this decline accelerates resulting in sarcopenia. A very important result of this decline is the unfortunate event of falling. Maintaining strength and balance is so important as we age. The data shows that death rates due to falls accelerate after the age of 55. And for individuals over the age of 60 that fall and fracture a femur, 10-30% will die within a year and most will not return to normal activity.
The bottom line here, is that training muscle strength, and improving mass should be your focus to
slowing your decline in overall function.
Basic Science of Muscle Contraction
Strength training refers to the process of performing an intentional contraction of skeletal muscle to improve and increase its ability to stabilize, perform a movement and contribute to metabolic balance.
There are 3 types of muscle contractions that our muscles perform with daily activity or intentionally as I mentioned. Strength, endurance and stability are all improved with these types of contractions. These are; an isometric contraction, a concentric contraction and an eccentric contraction.
Isometric is a contraction of the muscle with no motion through the joint of attachment or origin. Isometrics are usually implemented for neurological, stabilization and/or rehabilitation purposes. If stability is the goal, then isometrics are used.
Concentric is when a muscle contract resulting in movement in which the muscle shortens, and bones move closer together. This occurs with daily activity and with most strength or endurance training.
Eccentric is when a muscle contracts but the muscle lengthens rather than shortens. This is an important type of contraction that is often underutilize with training. But is very common with normal daily activity and is often times used in rehabilitation and corrective exercise training.
Another concept I need to mention here is muscle fiber type. Without going into a lot of detail our skeletal muscles consist of two main types. Type 1 (slow twitch) muscle fibers are basically those that are slow and aerobic, and can contract for longer periods of time as in endurance training. They don’t fatigue very quickly and are more associated with cardiovascular fitness.
Type 2 (fast twitch) muscle fibers are those that metabolically contract much quicker and are more powerful. They also fatigue much more quickly. These muscle fibers are important to train because they help prevent falling as we age.
Muscle Training
Following up on the above muscle science discussion, I want to get into the common types of actual muscle training. We train for one or all of the types of muscle function, by training for endurance, strength or power. Try not to get these confused in your training.
Muscular Endurance is the ability of a muscle or group of muscles to sustain repeated contractions for an extended time without fatiguing. Muscular endurance can be utilized in all three of the above contractions as long as it is for an extended period of time. For example, you are doing endurance training using resistance (dumbbells, tubing, cables, body weight) when performing more than 12 repetitions. Another example of muscular endurance training is with long distance running or holding a plank for a long time.
In the world of muscle training if you are doing a greater number of repetitions or holding a contraction for a longer time, you are doing endurance training, not strength or power training. This type of training is associated more with type 1 fibers and cardiovascular fitness.
Strength Training is then the ability of a muscle or group of muscles to exert greater or maximum force against a resistance. This type of training focuses on type 2 fibers, and they fatigue more quickly if the resistance is appropriate. Strength training is involved when you perform 8-10 repetitions with a reserve of 2 reps. You don’t max out, but you should feel like that last few reps are difficult to perform. This is when you truly develop strength and muscle mass. It is important to recognize that to build real strength your program should progressively increase the load for muscle fiber adaptations to occur. This strength training is what I am emphasizing in this article because of the benefits to healthspan. I must clarify that there a lot of different ways to perform strength training, but for our purpose here, I recommend 3 sets of 8-10 repetitions 3-4 times a week, and progress the load when appropriate. Progression is the key! However, no need to get fancy with strength training unless you have more advanced goals. Getting help from a fitness professional will go a long way in reaching your strength goals.
Power Training is when you simply add speed to a strength movement. This is often utilized for power lifting competition and specific sports training. We lose both strength and power as we age (sarcopenia), thus it is important to maintain both, well in to our later years. If untrained you lose about half of peak muscle power by age 70. Real power training should be performed with the guidance of a professional in order to improve specific power movements, improve function, and to prevent injuries.
I hope you find this information helpful, and if you have any questions please reach out to me or any of our Personal Trainers.
Good Luck with Your Strength Training,
Mark Tolle, MS, ATC, CSCS
Fitness Manager – Sky Fitness
847-229-0292