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MID-SEASON
DONNA MARLOR
Contributing Editor for the Master Skier
Donna maintains a private practice in sports nutrition and weight management. She is a Registered Dietitian and member of the Sports and Cardiovascular practice group of the American Dietetic Association. A former NMU skier, she enjoys competing at the master's level in running and x-c skiing. www.DonnaMarlor.com
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I felt extremely fortunate to have found another snow-lover amongst the Vegas crowd, and a famous one at that. Harris has been credited with discovering the application for the compound creatine in sport.
Although creatine has not been proven to be a particularly useful supplement for endurance athletes, numerous scientific studies have demonstrated it to be an effective nutrition aid for anaerobic strength sports.
“I know from personal experience how much you use the arms and
legs in X-country and that as you get older it is the arms that get
more tired. Beta-alanine supplementation/muscle carnosine elevation
will certainly help in delaying the kinetics of muscle pH decrease in
arm muscles.” Roger Harris, PhD, School of Sports, Exercise and Health Sciences, UK
Flying into Las Vegas for the International Society of Sports Nutrition (ISSN) conference, I could see waves of intense heat like a mirage rising from the strip. One-hundred and three degrees.
Unbelievably, crowds of heat worshiping tourists were out on the street - eating, drinking and gambling. Wearing sunscreen? I don’t think so. Coming from the sweet June climate of the Upper Peninsula of Michigan, I felt like an egg sizzling in a cast iron frying pan as I made my way to the ISSN conference center.
Standing by my research poster with its wintry race scenes, I was feeling completely out of season. Then I heard a voice say, “I love snow.”
Dr. Roger Harris, professor at the University of Chichester in the UK, was eyeing up my research poster with great interest, taking in the sunny, brilliant snow scenes of the races in the French Alps.
“I was raised in Sweden, and will retire in a years’ time.” He went on to describe his retirement Eden as “six months snow with frozen lake, mixed birch and coniferous forest, followed by six months sun with two months rain inclusive.”
But Dr. Harris was not at this conference to talk about creatine. It was his latest research on beta-alanine supplementation and it’s affect on anaerobic metabolism that caught my attention.
Could a natural amino acid improve my 5K time at the start of a marathon race? Dr. Harris thoughtfully considered my question for a moment, then we started to talk about the possibilities.
Carnosine as an Acid Buffer
While scientific research has unquestionably proven that lactic acid production is ultimately a good thing, we know that excessive hydrogen ion production that occurs as a byproduct can cause trouble.
As Northern Michigan University coach Sten Fjeldheim said so eloquently one day when I brought up the topic of lactic acid, “if you’re not in the race in the first 5K, you’re not in the race…but we’ve all felt the beast that raises it’s ugly head (as a result)”.
Back to Las Vegas. Harris, who had made his life’s work studying ways to boost the anaerobic staying power of muscle, had this to say about improving my chances for an explosive first 5 K start to a race.
“There are few natural buffers to hydrogen ions that can act to neutralize and help maintain a normal pH. Carnosine, which is a deceptive made from beta-alanine and histamine, is the only buffer within the muscle that can be increased through supplementation, or a combination of diet plus supplements.”
Cross-country skiers, Harris acknowledged, may or may not benefit from loading carnosine levels. Studies done with male runners showed no improvement in sprint performance following a 28-day loading protocol, however, male cyclists following a loading protocol for 10 weeks demonstrated an increase in total workload. Female subjects following a 28-day loading protocol also shown an increase in total time to exhaustion during maximal cycle ergometry performance.
According to Harris, muscle does have the natural means to counteract hydrogen ions through carnosine, but aging and diet can affect that capacity.
In early studies, they had examined the carnosine content of muscle from subjects who typically ate vegetarian vs. carnivorous diets. In the United Kingdom (UK) lacto-ovo vegetarians were found to have approximately half the muscle carnosine content of meat eaters; Australian Sports Science students, moderately active, had approximately 1-1/2 times the level of carnosine compared to the lacto-ovo vegetarians.
Differences in muscle carnosine reflected the consumption or lack of food sources of carnosine or the precursors, beta-alanine and histidine in the diet.
Aging also is associated with a decrease in carnosine levels, said Harris, whose lab has compared inactive 65–80 year olds to healthy 25 year olds. Older subjects tested showed a 53% reduction in carnosine levels compared to an active, healthy group of students, which translates into about a 7% or more reduction in buffering capacity.
Possible causes for the change in the carnosine content were thought to be reduced physical activity, reduced meat intake or the result of progressive denervation.
Raising Carnosine Level in Muscle
Master Skiers desiring to keep their competitive edge despite the challenges of limited training time and the changes rendered by the ticking biological clock may want to maximize carnosine content in their muscle.
Perhaps Roger Harris said it best: “the reasons for the improvement in performance are very straight forward and a consequence of the increase in intracellular buffering enabling greater lactate tolerance.”
Carnosine Loading Protocol
Aim for 2 grams to 4 grams of beta-alanine per day. Start four to six months before the peak performance event, depending on whether using diet alone or supplements combined with diet.
Diet Only:
A 150g (3-oz) serving of roasted turkey breast should provide 500mg of beta-alanine. Chicken breast is also a good source. Other meats (pork, beef) have about half this content. Eat servings in divided doses for maximum benefit. Goal is ≤2000 grams/day.
Diet + Beta-Alanine Supplements:
Do not exceed 1g in a single dose (2 x 500mg capsules, ideally close to food or you will get symptoms of paraesthesia). The parethesia is not harmful, but is very uncomfortable. A combination of diet and beta-alanine supplements can raise carnosine levels in 3-4 months.
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