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Beta- hydroxy -beta- methylbutyrate : Useful to athletes?

Beta- hydroxy -beta- methylbutyrate : Useful to athletes?. David Castille. Background. HMB first discovered by Dr. Steven Nissen and released in 1995 Purported to have beneficial effects on lean body mass, muscular strength, and body composition

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Beta- hydroxy -beta- methylbutyrate : Useful to athletes?

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  1. Beta-hydroxy-beta-methylbutyrate:Useful to athletes? David Castille

  2. Background • HMB first discovered by Dr. Steven Nissen and released in 1995 • Purported to have beneficial effects on lean body mass, muscular strength, and body composition • Metabolite of the branched chain amino acid leucine

  3. HMB • Approximately 5% of Leucine is converted to HMB. (would require 60g of leucine to equal 3 g dose used in studies) • Appearance in blood peaks about 1-2 hours post consumption • Newly developed HMB-FA peaks blood levels higher, faster, and longer • Evidence to date suggests HMB consumption is deemed safe for both young and old populations

  4. Proposed mechanisms • Ubiquitin protein breakdown pathway • Cholesterol synthesis • Stimulation of mTOR • Theoretically, HMB will only truly work under conditions of elevated protein damage

  5. Previous literature • Varied results, but many showed decreases in Creatine Kinase, Lactate Dehyodrogenase. Also decrease in urea nitrogen (suggesting greater nitrogen balance) • Training status seems to play a role • Trained individuals require a more intense stimulus to see an effect • Timing of intake • Few studies have taken this into account, but seems important when taken before exercise bout.

  6. Study #1 • Dr. Jacob Wilson • University of Tampa • 24 well resistance-trained males • 12 week periodization • Included bench, squat, deadlift, etc • Controlled for diet • HMB-FA was timed 30 minutes pre-exercise

  7. Study #2

  8. Study #2 • Overreaching model • 2 weeks • Trained Monday – Thursday • Friday – Powerlifting competition (max on bench, squat, and deadlift) • Saturday - Wingates

  9. Study #2 • HMB-FA group experienced no significant % change in powerlifting results

  10. Conclusions • In situations of extreme muscle catabolism/protein breakdown, HMB may be effective but further research is needed • Timing intake and dose amount seems to play a role in the efficacy of HMB supplementation

  11. Found in • Small amounts of HMB in: • Catfish • Alfalfa • Grapefruit • High leucine foods: • Eggs • Soybeans • Spirulina • Moose, elk, buffalo (wild game) • Fish • HMB is nearly impossible to obtain in efficacious dose amounts prior to exercise from food sources…

  12. Questions?

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