Aging is associated with a general decline in physiological function that leads to increased mortality and morbidity. One of the most recognized changes with age is sarcopenia, an age-related progressive loss of muscle mass that leads to a reduction in metabolism function, muscle weakness, limited mobility, and increased susceptibility to injury, and a loss of independence. Sarcopenia is the largest contributing factor to strength decline and associated disability in older men and women, especially at the onset of 50 years of age. In fact, according to Statistics Canada the life expectancy of an average Canadian in 1996 was 78.3 years and the average independent free living years was 68.6. In other words, the average Canadian is losing approximately 10 years of independent free living. Naturally, many doctors, exercise physiologists, and rehabilitation experts have been drawn to the question of how to prevent the loss in muscle mass and how to possibly reverse it so that the average Canadian can live healthier into their golden years.

One of the factors that could play a key role in triggering sarcopenia is the accumulation of reactive oxygen species, also known as free radicals. Free radicals can cause severe damage if they are not promptly eliminated by exercise and the action of anti-oxidant agents, such as those found in the foods and supplements we eat. It should be noted that we do not have to succumb to this aging process. Strength training and timely protein ingestion are two of the most effective ways to alleviate the age-related loss in muscle.

1. Strength training: also known as resistance training and/or weight training. Evidence that resistance training is of benefit to older adults is overwhelming. This method has been proven to delay, prevent, and reverse the effects of sarcopenia. Interestingly, it has been shown that a vigorously exercising population can delay the age-related disability by approximately 15 years.

It is not always easy to formulate an adequate standardized exercise protocol for each individual because establishing the most effective frequency, duration, and loads of the exercise may vary significantly from one individual to another. To complicate matters, prior fitness levels, experience, age, gender, and genetic predisposition influence optimal training design. However, I do offer the following general exercise prescription and program guideline. You should complete 2-4 sets of 8-12 repetitions and each muscle group should be exercised 2-3 days per week. Since eccentric loading may promote more of a muscle building stimulus, you should lower the weight for 4 seconds and raise the weight for a count of 2 seconds.

2. Protein ingestion: A reduction in protein intake with age has been shown to be a significant contributing factor to the age-related reduction in muscle mass. What normally goes overlooked is when protein is ingested. For the aged population, it matters considerably when a person eats protein as opposed to the quantity of protein consumed. It has been shown that consuming protein 2 hours after resistance exercise does very little for muscle growth, on the other hand, when protein is consumed immediately after exercise there is much greater efficacy in stimulating muscle growth. Furthermore, the type of protein is equally important. In a recent study, muscle protein synthesis was stimulated to a greater degree when elderly subjects consumed a larger dose of leucine (an amino acid found in most protein supplements), whereas the small dose of leucine was ineffective in stimulating muscle growth.


 

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To achieve the highest potential to alleviate the age-related muscle loss, I do offer the following nutritional guideline. When purchasing a protein supplement (which I strongly recommend), make sure it is a whey protein isolate and contains greater than 1.5 grams of leucine per serving. Take two servings within 1 hour after resistance training. Take 1 serving on the days you are not exercising.

In conclusion, the loss of skeletal muscle mass with aging (sarcopenia) constitutes a major problem for the aging population and is a major contributor to the reduced ability to continue to carry out daily physical tasks successfully and safely. Stimulating the anabolic process (building process) by resistance training and timely consumption of a protein containing a large dose of leucine causes a bigger increase in net muscle growth in the aging population allowing them to live independently and healthier for a longer period of time.