23Dec12- Sunday

I had a horrible last week of training, but will be back ready to roll when the GM Box opens back up....

I'll try to post some intersting reading over the next week.

Have a great Christmas Holiday.    Think about what you want and make a plan to get it.

Home   >  

The Paradox of the Aging Athlete

By Darin Deaton PT, DPT, OCS on December 13, 2012

Part-1 Muscle

In the world of CrossFit and other athletic circles, there is a wide range of age in the athletes. As an affiliate owner, coach, physical therapist and “slightly” older athlete, I have been contemplating on how I can better serve the needs of all athletic ages.
So, we might approach our athletic population with one simple question: Is there a “need” for training models, methods or techniques that better suit the young, middle aged and older athlete?  I think we can all agree that there are certain methods that are more appropriate and safer for the younger population, thus CrossFit Kids. Certain types of exercises, loads and intensities are not appropriate for the growing non-matured skeletal frame.

Darin Deaton

Through general observation, visiting other affiliate’s boxes, watching videos and the CrossFit Games, I estimate that the average age of a CrossFit athlete appears to be approximately 25-30.  But what about the other end of the spectrum? And at what age would we consider an athlete, “older,” and modify their training? To better develop a construct by which to work upon, I decided to do some basic research on the physiological differences of human tissues based on the aging cycle. This is not a recipe for training, but a starting point to discuss if there is a need to modify CrossFit training to populations based on the aging process.
Training variables such as type of exercise, intensity, frequency, loads, repetition count, rest and recovery cycles, should be areas of investigation for all coaches.  To propose or develop a program with too rigid of a structure does not allow for the flexibility to modify training variables. A good example would be rest and recovery. The rest and recovery time of a 20 year old athlete is significantly different than that of a 45 year old athlete. All variables in training should be modified to best meet the needs of the individual athlete and promote maximum efficacy in results. My initial hypothesis is that CrossFit training should be modified or scaled to better serve the needs of the aging athlete, and thus our training programming or rest model may differ from the younger to older athlete.
Facts to Consider – Physiology of aging muscle and Connective Tissues
Muscle Physiology
Muscle protein loss in aging has been associated largely with skeletal muscle protein loss (Cohn et al,1980)
Evidence suggests that decrease in muscle mass with aging accounts for; decrease in BMR, decrease in V02 max (BLSA, Tzankoff and Norris, 1978)
Decreased muscle force production begins about 45 yoa,  more rapid loss > 70 years old, 25-30% decrease more in the lower than upper extremities
Decreased muscle force production maybe due to a decrease in muscle cross sectional area (CSA)
Cadaver Studies: cross sections of entire vastus lateralis decrease of 10% in CSA between 30-50 yoa, decrease in 25-30% CSA between 50-80 years (Lexall, et al, 1988)
Resistance training-related changes in muscle strength, muscle size, fiber type, and myosin heavy chain isoform composition in 11 elderly subjects (age range, 85–97 years) after 12 weeks of heavy resistance training (80% of 1 RM) were examined. Twelve subjects constituted a control group. Resistance training increased isometric knee extensor strength 37% (P<0.05) and isokinetic knee strength 41–47% (P<0.05). Lean-quadriceps cross-sectional area increased 9.8% (P<0.05). Muscle fiber hypertrophy occurred only in the type 2 fibers (22% (P<0.05)). Type 1 fiber-type area percentage decreased [4.0 % (P<0.05)] whereas fiber-type area percentage of type 2a fibers increased [5.9% (P<0.05)] (A. I. Kryger,  J. L. Andersen, 2006)
Endurance capacity of muscle function appears preserved, recovery of contractile properties after fatiguing work slower (Davies et al, 1983, 1984; Larsson, 1979)
Overall, these studies suggest that the maximal force/unit area can remain relatively constant, or improve with training to late ages in life. Muscle function with age also suggests that the intrinsic quality of the muscle can produce force in old as in young. It appears that the loss of force production is more due to muscle atrophy, disuse, loss of CSA due to in part a decrease in fast muscle fiber size. I think many of us have made the assumption that we can train older clients and achieve strength improvements, and we have observed this through experiential data. But these studies help support our assumptions and experiences.
Older athletes can create muscle hypertrophy and development through resistance training at varying levels. The ability to develop muscle does not appear to be the weakest link. But, on the other hand, lack of activity, disuse or lack of disruption of homeostasis, can create a decrease in muscle fiber size, function and the physical capacity of an older person. It is imperative that we gradually introduce training to the older population, but that we also educate them to the fact that homeostasis or equilibrium of the target tissue must be disrupted.
As a general population, we have been sold by the commercial exercise industry that normal human capacities are exercise! For example, in the world of physical therapy and the fitness community, walking is considered exercise. This may be true if the athlete has a lack of conditioning to walking as a daily task or athletic endeavor, and it elicits a significant disruption to their body systems.  But, this is definitely not true if walking does not disrupt homeostasis. In other words, you need to challenge your body to a level of exercise that it cannot sustain.
CrossFit style training can have the potential to disrupt homeostasis. But we must be assured that during training we are not potentially damaging important soft tissues due to the aging process. Having injured athletes does not promote our primary goal of developing elite fitness. So where do we go from here? In the next article we will review the effects of aging on connective tissue such as tendon and ligaments.

Part 2 Connective Tissue

Prior to writing this, my thoughts were that the connective tissue is an area where we proceed with caution. CrossFit methodology teaches us that we consider exercise intervention scaling or modification, “in degree not kind.” I agree with this approach as long as the movement and excursion patterns support these tissues. What is connective tissue? Connective tissue can be considered any human tissue that, “holds together or attaches,” bones, muscle to bone, muscle compartments, and joints. There are three tissues that concern us, ligaments-attaching bone to bone, tendons-attaching muscle to bone and fascia holding muscle compartments and tissues together. We will also discuss joint load bearing tissues such as articular and hyaline cartilage in the next writing.
Let’s review structures and components first. Within these tissues, cells consist of fibroblast and the fibers are elastin and collagen. The ground substance is comprised primarily of glycosaminoglycans, GAG’s(linked to proteins=proteoglycans) and associated proteins fibronectin and laminin.
Age changes within connective tissue cells have proven to be few. On the contrary, the aging changes within fibers are many. With collagen fibers there is decreased solubility, reducible cross linkages stabilize, and increased rigidity. With elastin fibers there is decreased production, increased fragmentation, rupture and loss of rebound. These morphological changes in fiber produce less tissue flexibility, contracture and a loss in elastic capacity. So, for the older athlete this may contribute to the loss in tissue excursion and functional range of motion.
This simply means that the older athlete, if they have not been actively involved in aflexibility and mobility program, will naturally have less joint, tendon and ligament movement capacity. These tissues are also at greater risk, due to lack of elasticity, when performing jerking or more ballistic movements as associated with many CrossFit type exercises. The common complaint of older athletes after a CrossFit WOD might be muscle soreness and also pain that originates from the connective tissue attachments and joints. If this pain does not resolve within 48-72 hours attention should be given to the exercise intervention and intensity.
When starting CrossFit with older athletes, there should be greater attention given to transitioning and scaling the movements and limiting ballistic, high force repetitive movements at the ends of their available ranges. Exercises such as kipping pull ups need to be gradually transitioned into training. Controlling quick, ballistic and bouncing movements will help to protect these tissues early on in CrossFit training. If we are not careful, the lack of elasticity in these tissues can put these clients at greater risk to potential injury.