Creatine in Sport Richard B. Kreider, PhD, FACSM, FI SSN, FACN - PowerPoint PPT Presentation

Creatine in Sport Richard B. Kreider, PhD, FACSM, FI SSN, FACN Professor & Head, Department of Health & Kinesiology Thomas A. & Joan Read Endowed Chair for Disadvantaged Youth Director, Exercise & Sport Nutrition Lab Texas A&M University rkreider@hlkn.tam u.edu w w w .ExerciseAndSportNutritionLab.com Declarations: Scientific consultant for Woodbolt International; legal consultant on cases related to nutritional supplementation; have received grants from industry including AlzChem.

Thank You! SCIENTIFIC COMMITTEE LOCAL ORGANIZER Prof Theo Wallimann (President), formerly ETH Zurich, CH Prof Roger Harris (Co-President), formerly University of Chichester, UK Prof Eric S. Rawson Bloomsburg University, USA Dr. Olivier Braissant University Hospital of Lausanne (CHUV), CH Prof Arend Heerschap Radboud University Nijmegen Medical Center, NL Assoc Prof Andreas Bender University of Munich, D

hlknw eb.tam u.edu

Dedicated to evaluating the interaction between exercise and nutrition on health, disease, rehabilitation, and performance w w w .ExerciseAndSportNutritionLab.com

Overview Brief Overview  Metabolic Role  Ergogenic Value  Prevalence of Use  Other Applications for Sport  Recovery  Injury Prevention  Rehabilitation  Neuroprotection  Conclusions 

Metabolic Role of Creatine  The primary metabolic role of Free Energy Change in Energy-Rich creatine (Cr) is to combine with a Phosphates phosphoryl group (Pi) to form PCr through the enzymatic reaction of creatine kinase (CK). Creatine + Phosphate CP  As ATP is degraded into ADP and Creatine Kinase (-10.3 kcal/mmol) Pi to provide free energy for Free Energy metabolic activity (~7.3 kcal), ADP + Phosphate ATP the free energy released from the hydrolysis of PCr into Cr + Pi (-7.3 kcal/mmol) Free Energy (10.3 kcal) can be used to resynthesize ATP. ADP AMP + Phosphate  This helps maintain ATP (-7.3 kcal/mmol) Free Energy availability particularly during * Free energy released represents energy maximal effort anaerobic sprint- needed under physiological conditions for type exercise. resynthesis

Metabolic Role of Creatine  The CK/PCr system also plays an important role in shuttling intracellular energy from the mitochondria into the cytosol.  The CK/PCr energy shuttle connects sites of ATP production (glycolysis and mitochondrial oxidative phosphorylation) with subcellular sites of ATP utilization (ATPases). Proposed creatine kinase / phosphocreatine (CK/PCr) energy shuttle.  ATP and PCr can then CRT = creatine transporter; ANT = adenine nucleotide translocator; ATP = adenine triphosphate; ADP = adenine diphosphate; OP = diffuse from mitochondria to oxidative phosphorylation; mtCK = mitochondrial creatine kinase; G = glycolysis; CK-g = creatine kinase associated with glycolytic enzymes; the cytosol to fuel energy CK-c = cytosolic creatine kinase; CK-a = creatine kinase associated with subcellular sites of ATP utilization; 1 – 4 sites of CK/ATP needs. interaction. Adapted from Wallimann et al, 2011.

Metabolic Role of Creatine Role of mitochondrial creatine kinase (mtCK) in high energy metabolite transport and cellular respiration. VDAC = voltage-dependent anion channel; ROS = reactive oxygen species; RNS = reactive nitrogen species; ANT = adenine nucleotide translocator; ATP = adenine triphosphate; ADP = adenine diphosphate; Cr = creatine; and, PCr = phosphocreatine. Adapted from Wallimann et al, 2011.

Changes in [ ATP] and [ PCr] During Maxim al Effort Sprint Exercise 120 -5% to -10% 100 Percent Change ( % ) 80 ATP 60 PCr 40 -40% to -80% 20 0 0 2 4 6 8 10 Seconds

Effects of Repeated Maxim al Effort Sprints on [ PCr] 100 90 80 Change in [ PCr] 70 60 50 40 30 20 It takes 30 to 90 sec (1:4 or 1:5 work:rest ratio) for the majority of PCr stores to be • replenished following sprint exercise. 10 ATP resynthesized from aerobic metabolism is used to replenish PCr stores • 0 Pre-1 Post-1 Pre-2 Post-2 Pre-3 Post-3 Pre-4 Post-4 Sprint

Supplem entation Protocols High Dose Protocol (Early Studies) • Ingest 15-25 g/d (0.3 g/kg/d) during • training Loading/Maintenance Protocol • Ingest 0.3 g/kg/d (15-25 g/d) for 5-7 d • Ingest 3-5 g/d to maintain • Low Dose Protocol • Ingest 3-5 g/d (0.03 g/kg/d) during • training Cycling Protocol • Load/maintain during training and • reduce/abstain between training periods Takes 4-6 weeks for muscle creatine levels • to return to baseline after loading

Bioavailability Muscle Total Creatine Stores 180 Purported Upper Limit 155 160 140 140 120 120 100 mmol/kg DW 100 80 60 40 20 0 Vegetarian Normal Creatine Loading Creatine Loading with CHO or CHO/PRO Approximate muscle total creatine levels in mmol/kg dry weight muscle reported in the literature for vegetarians, individuals following a normal diet, and in response to creatine loading with or without carbohydrate (CHO) or CHO and protein (PRO). From Kreider & Juhn, JENB, 2011.

Ergogenic Value

Theoretical Benefits  Increased single and repetitive sprint performance  Increased muscle mass & strength adaptations during training  Enhanced glycogen synthesis  Increased anaerobic threshold  Possible enhancement of aerobic capacity via greater shuttling of ATP from mitochondria  Increased work capacity  Enhanced recovery  Greater training tolerance

Athletic Events that Creatine May Benefit • I ncreased PCr • Oxidative Metabolism • Track sprints: 100, 200 meters Basketball • • Swim sprints: 50 meters Soccer • • Pursuit cycling Team handball • Tennis • I ncreased PCr Resynthesis • • Basketball Volleyball • • Field hockey Interval Training in Endurance • Athletes • Football (American) • Ice hockey • I ncreased Muscle Mass American, Australian football • • Lacrosse Bodybuilding • • Volleyball Heavyweight wrestling • • Reduced Muscle Acidosis Power lifting • • Downhill skiing Rugby • • Rowing Track/Field events • • Swim events: 100, 200 meters (Shot put; javelin; discus) • • Track events: 400, 800 meters Weightlifting • • Enhanced Training • Most sports Adapted from Williams, Kreider, and Branch, 1998.

Short-Term Supplem entation Short-term creatine • supplementation improves: • body mass by 1-2 kg in first week of loading; • maximal power/strength (5-15%); • work performed during sets of maximal effort muscle contractions (5-15%); and, • single-effort sprint performance (1-5%); and, • work performed during repetitive sprint performance (5-15%). Kreider & Jung, JENB, 2011

Effects on Exercise Perform ance Reference Methods Results Volek et al. The amount of work performed ↑ during 5 25 g/d for 7 days MSSE, 1999 sets of bench press and jump squats Maximal power and work performed ↑ Wiroth et al. 15 g/d for 5 days during 5 X 10 s cycling sprints with 60 s EJAP, 2001 rest recovery Mujika et al. Repeated sprint performance ↑ (6 X 15 m 20 g/d for 6 days MSSE, 2000 sprints with 30 s recovery) 20 g/d Mero et al. + 2 X 100 m swim performance ↑ JSCR, 2004 sodium bicarbonate 0.3 g/kg for 6 days Resting and post-exercise creatine and PCr Preen et al., content ↑ 20 g/d for 5 days MSSE, 2001 Mean work performed and total work performed ↑

Long-Term Supplem entation  Studies show long-term creatine supplementation enhances quality of training generally leading to 5- 15% greater gains in strength and performance.  Creatine supplementation during resistance-training typically promotes a 1-3 kg greater gain in FFM in 4 – 12 weeks  Muscle biopsy studies show gains are due to greater protein content in muscle and not water. Kreider & Jung, JENB, 2011

Effects on Training Adaptations Author Methods Results Total creatine & PCr content , maximal strength (20-25%), maximal intermittent Vandenberghe 20 g/d X 4 days; exercise capacity of the arm flexors (10- et al., JAP, 1997 5 g/d X 65 days 25%), and FFM by 60 % ↑ during 10 wks training in women Kreider et al., FFM and repetitive sprint performance ↑ 15.75 g/d X 28 days MSSE, 1998 during off-season college football training Body mass, FFM, 1 RM bench press, combined 1 RM squat and bench press, Stone et al., ~10 or 20 g/d vertical jump power output, and peak rate of IJSN, 1999 with and without pyruvate for 5 wks force development ↑ in 42 division college football player Muscle total creatine and PC, FFM, type Ⅰ , Volek et al., 25 g/d X 7 days; Ⅱ a, & Ⅱ b muscle fiber diameter, bench MSSE, 1999 5 g/d X 77days press, squat 1RM, and lifting volume ↑ in 19 resistance trained athletes Total body mass, FFM, and thigh volume, 1 Willougby et al., RM strength, myofibrillar protein content, 6 g/d X 12 wks MSSE, 2001 Type Ⅰ , Ⅱ a, & Ⅱ x MHC mRNA expression, and MHC protein expression ↑

Prevalence of Use

Prevalence of Use in Sport  Widespread commercial availability and supplementation among athletes began in the early to mid- 1990’s  A number of survey studies have been conducted to assess supplement usage rates in various athletic and military populations  While athletes represent a sizable segment of creatine users, individuals interested in enhancing fitness and physique augmentation represent the largest segment of sport and nutritional supplements