Wednesday, May 6, 2009

Glycine propionyl-L-carnitine increase in Exercise Performance

I wanted to post a note about this article a while back but did not have time. I found this very interesting in that it may help develop Peak power and at a minimuim should warrent a larger scale study. Any Questions Just ask.

"Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males," Jacobs PL, Goldstein ER, et al, J Int Soc Sports Nutr, 2009; 6(1): 9. (Address: Patrick L. Jacobs, Department of Exercise Science and Health Promotion, Florida Atlantic University, Davie, FL, 33314, USA. E-mail: ).

In a double-blind, placebo-controlled, crossover study involving 24 healthy male resistance trained subjects (average age: 25 years), supplementation with 4.5 grams glycine propionyl-L-carnitine (GPLC) 90 minutes prior to participating in an exercise testing protocol, was found to enhance peak power production and significantly reduce accumulation of blood lactate (16% less blood lactate production 14 minutes post-exercise), as compared to ingestion of a placebo. The authors state, "These findings indicate that short-term oral supplementation of GPLC can enhance peak power production in resistance trained males with significantly less LAC accumulation."

Testing: The assessment protocol consisted of five maximal effort 10-second cycle sprints performed with 1-minute active recovery periods between bouts. While Wingate type testing is typically performed using a single 30 second work period, repeated 10 second sprints have been used when testing exercise capacities similar to those required in relatively intense exercise. The sprints were performed using a Monarch 894E leg ergometer (Monarch, Varberb, Sweden) outfitted with pedal cages. The external resistance applied was equivalent to 7.5% of each subject's body mass. The testing protocol included a 10-minute warm-up period cycling on the test bike at a pace of 60 RPM, without external resistance. Following the warm-up period, subjects were directed to gradually increase the pace of their pedalling over several seconds until they reached a maximal pace of unloaded sprinting. At this point, with a verbal cadence, external resistance was applied thereby initiating a 10-second period of sprint testing and data collection. Verbal encouragement was provided by the investigators to continue sprinting at maximal pace throughout the 10-second bout. Subjects were directed to continue pedalling at a slower controlled pace during the 1-minute active recovery periods. With five seconds remaining in the recovery period, subjects were again directed to gradually increase their pedalling to a sprinting pace for the second sprint. This procedure was continued for a total of five 10-second sprint bouts.
Anaerobic power output of the sprints was determined using the SMI OptoSensor 2000 (Sports Medicine Industries, Inc., St. Cloud, Minn). Values of power output determined included peak power (PP) and mean power (MP) which in this case were the average values of power output during the first five seconds and total ten second period, respectively. The third power output measure was a value of power decrement (DEC) in which the difference in power output between the first and second five second periods are expressed as a percentage of the first.
Blood lactate levels were assessed using the Accutrend® Lactate analyzer (Sports Resource Group, Inc., Pleasantville, NY). The analyzer was calibrated using the standard control solutions prior to each testing session. Lactate values were determined at rest and post-exercise at minutes four and fourteen. Heart rate was measured using a Polar HR monitor system with values assessed at rest, during the final 5 seconds of each sprint as well as four and fourteen minutes following completion of the fifth sprint. Thigh girth was assessed using a Gulick tape with circumferential measurements taken 15 mm superior to the patella. Thigh girth was measured at rest and four minutes following completion of the final sprint interval.

Now I know the sample size was small but I think the methods are sound and the results are interesting and show a significant increase in anaerobic power.

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