ArticlePDF Available

Abstract

Anecdotal reports suggest that creatine supplementation during intense training and competition may increase the incidence of muscle cramping and injury. This study examined the effects of creatine supplementation on cramping and injury during collegiate baseball training and competition. Thirty-nine Division I baseball players participated in this study. Twenty-one (54.0%) of the thirty-nine athletes ingested 15 to 25g/d of creatine for 5 days followed by 5 g/day of creatine that was mixed with sports drinks or water. Athletes who were non-creatine users had access to a carbohydrate drink that contained no creatine (placebo) during the training/competition period. Injuries treated by the athletic training staff were recorded and categorized as cramping, heat/dehydration, muscle tightness, muscle strains, non-contact injuries joint injuries, contact injuries, and illness. The number of practices missed due to injury and illness were also recorded. While no heat/dehydration events were reported by either group, results revealed that creatine-users had significantly fewer total injuries, ?2 (1)=4.69, p=0.03 than non-creatine users (p<0.05). However, there were no significant differences between groups regarding cramping, ?2 (1)=2.94, p=0.08, muscle tightness, ? 2 (1)=3.01, p=0.08, muscle strains, ?2 (1)=2.92, p=0.08, non-contact joint injuries, ?2 (1)=1.04, p=0.31, contact injuries, ?2 (1)=0.009, p=.92, illness, ?2 (1)=0.02, p=0.95, missed practices due to injury, ?2 (1)=.103, p=0.74, and players lost for the season, ?2 (1)=2.45, p=0.11. Based on the findings in this investigation, creatine supplementation during collegiate baseball training and competition does not appear to increase the incidence of injury or cramping. Additional research is warranted to evaluate the effect of creatine supplementation on athletes training in hot/humid climates.
Creatine Supplementation, Cramping and Injury in Baseball
16
JEPonline
Journal of Exercise Physiologyonline
Official Journal of The American
Society of Exercise Physiologists (ASEP)
ISSN 1097-9751
An International Electronic Journal
Volume 6 Number 4 November 2003
Sports Nutrition
THE EFFECTS OF CREATINE SUPPLEMENTATION ON CRAMPING AND INJURY
OCCURRENCE DURING COLLEGE BASEBALL TRAINING AND COMPETITION
MICHAEL GREENWOOD1, RICHARD B. KREIDER1, LORI GREENWOOD1, DARRYN WILLOUGHBY2,
ALLYN BYARS3
1 Department of HHPR, Baylor University, Waco, Texas; 2 Department of Kinesiology, Texas Christian University, Fort
Worth, Texas; 3 Human Performance Laboratory, Department of HPER, Hardin-Simmons University, Abilene,Texas
ABSTRACT
THE EFFECTS OF CREATINE SUPPLEMENTATION ON CRAMPING AND INJURY OCCURRENCE
DURING COLLEGE BASEBALL TRAINING AND COMPETITION. Michael Greenwood, Richard B.
Kreider, Lori Greenwood, Darryn Willoughby, Allyn Byars . JEPonline. 2003;6(4):16-23. Anecdotal reports
suggest that creatine supplementation during intense training and competition may increase the incidence of muscle
cramping and injury. This study examined the effects of creatine supplementation on cramping and injury during
collegiate baseball training and competition. Thirty-nine Division I baseball players participated in this study. Twenty-
one (54.0%) of the thirty-nine athletes ingested 15 to 25g/d of creatine for 5 days followed by 5 g/day of creatine that
was mixed with sports drinks or water. Athletes who were non-creatine users had access to a carbohydrate drink that
contained no creatine (placebo) during the training/competition period. Injuries treated by the athletic training staff were
recorded and categorized as cramping, heat/dehydration, muscle tightness, muscle strains, non-contact injuries joint
injuries, contact injuries, and illness. The number of practices missed due to injury and illness were also recorded.
While no heat/dehydration events were reported by either group, results revealed that creatine-users had significantly
fewer total injuries, ?2 (1)=4.69, p=0.03 than non-creatine users (p<0.05). However, there were no significant
differences between groups regarding cramping, ?2 (1)=2.94, p=0.08, muscle tightness, ?2 (1)=3.01, p=0.08, muscle
strains, ?2 (1)=2.92, p=0.08, non-contact joint injuries, ?2 (1)=1.04, p=0.31, contact injuries, ?2 (1)=0.009, p=.92,
illness, ?2 (1)=0.02, p=0.95, missed practices due to injury, ?2 (1)=.103, p=0.74, and players lost for the season, ?2
(1)=2.45, p=0.11. Based on the findings in this investigation, creatine supplementation during collegiate baseball training
and competition does not appear to increase the incidence of injury or cramping. Additional research is warranted to
evaluate the effect of creatine supplementation on athletes training in hot/humid climates.
Key Words: Exercise, Nutrition, Ergogenic Aids, Safety, Sport Injuries.
Creatine Supplementation, Cramping and Injury in Baseball
17
INTRODUCTION
Creatine supplementation has been reported to increase strength, enhance work performed during repetitive sets of
muscle contractions, improve repetitive sprint performance, and increase body mass/fat free mass (1-3). Consequently,
creatine has become a very popular nutritional supplement among athletes. The only documented side effect of creatine
supplementation reported in the scientific/medical literature has been weight gain (2-4). However, concerns have been
raised over the medical safety of creatine supplementation among athletes even though extensive research has yielded no
negative effects in the areas of endogenous creatine synthesis (5-7), renal function (8-15), muscle and liver enzyme efflux
(10,13,16-18), blood volume and electrolyte status (19-23), blood pressure (24-25), or general markers of medical
safety (13,14,18,25-36). Additionally, there have been only anecdotal reports that creatine supplementation during
intense training in hot and or humid environments may predispose athletes to increased incidence of muscle cramping,
dehydration, and/or musculoskeletal injuries such as muscle strains (37-39). Therefore, the purpose of this investigation
was to examine the effects of creatine supplementation on the incidence of dehydration/cramping and various
musculoskeletal injuries observed in NCAA Division I college baseball players during training and competition. It should
be mentioned that the present study was only conducted through the course of one season due to the August 2000
NCAA restrictions regarding the provision of various nutritional supplements (i.e., creatine) to athletes.
METHODS
Subjects
Injury rates of 39 Division I National Collegiate Athletic Association (NCAA) college baseball players participating in
the 2000 baseball season at a mid-southern state university were monitored during this study. Subjects who
volunteered to participate in this present study chose whether they wanted to take creatine or non-creatine containing
supplements (placebo) during training and competition. No subject reported taking additional ergogenic supplements
other than protein-carbohydrate shakes and or bars. All subjects underwent pre-season medical examinations and were
cleared to participate in baseball according to NCAA criteria. In addition, all athletes were provided medical
supervision by the team athletic training staff and physicians throughout the course of this observation period. Subjects
were informed as to the experimental procedures, which were established in accordance with the guidelines developed
by the American College of Sports Medicine. Informed consent statements were also signed in adherence with the
guidelines of the Internal Review Board for use of Human Subjects. Subjects were 20.3±1.0 yrs (range 1925 yrs),
180.0±7.0 cm (range 163190 cm) and 91.0±13.0 kg (range 75103 kg) upon reporting to spring baseball practice
prior to the 2000 competitive season.
Procedures
Injuries treated by the athletic training staff during the 2000 college baseball season were monitored during this study.
This was accomplished by having research personal attend training sessions, practice sessions and games and by
recording all injuries treated by the athletic training staff. The primary investigator confirmed the type, category and
degree of injury to the athlete with the certified athletic trainer when the injury occurred to ensure that the injury was
accurately recorded. Additionally, a tabulation of missed practices was recorded to monitor the length of time an athlete
was unable to participate due to their specific injury and not illness. The athletes were asked daily if they perceived any
side effects associated with the creatine supplementation and this information was than recorded by the certified athletic
trainer assigned to baseball. Injuries were categorized as cramping, heat disorders (e.g., dehydration, heat syncope),
muscle tightness, muscle strains, non-contact joint injuries (e.g., sprained ankles), contact injuries (e.g., injuries resulting
from collisions), illness, and the number of missed practices due to injury. These injuries were considered significant
injuries because they required medical attention and they involved some limitation from participation in training sessions,
practices and or games. Minor injuries that did not limit the athletes’ ability to participate in practices and/or games
(e.g., bruises, general soreness) and or require significant medical treatment were not recorded.
Creatine Supplementation, Cramping and Injury in Baseball
18
Supplementation Protocols
Subjects who volunteered for the study chose whether they wanted to take creatine while remaining subjects had access
to a non-creatine containing commercial sport drink which was designated the placebo. Creatine was added to sports
drinks or water that the players ingested following training sessions, practices, and competition during the five-month
period. Subjects turned in weekly logs to verify the subject’s compliance to the prescribed creatine dosage protocol.
The 21 subjects who chose to take creatine ingested, in an open label manner, 15.75 g/d of powdered creatine
monohydrate for 5 days and an average of 5 g/day thereafter in 5 g doses based on a formula known to increase
creatine concentrations in relation to the athletes body weight (1). Further, these specific creatine dosage protocols
were selected based on previous research recommendations (1). If for some reason a subject fell behind in taking
creatine, subjects (n=2 subjects on one occasion) ingested up to 10 g/day in order to adhere to the average dose of 5
g/day.
Training
Training consisted of resistance training and conditioning drills (1-2 h/day, 3 days/wk), preseason scrimmages (3-6
h/day, 2-3 days/wk), and practicing and competition during baseball season (2-5 h/day, 6 days/wk). Athletic coaches,
certified athletic trainers, and research assistants supervised all training sessions. Training/game averaged 211±67 min
per session with an average intensity of 3.0±1 on a 1 5 scale where 1 was equivalent to a stretching/warm-up and
throwing/batting practice the day prior to competition and 5 was equivalent to game competition. Environmental
conditions during training and competition ranged from 27 to 35 °C (mean 30.4±0.6 °C) and 59 to 91% relative
humidity (77.1±2.53%).
Data Analysis
The incidence of reported first time injuries observed in creatine users and non-creatine users for each category were
monitored and recorded during the study (Table 1). Injuries treated by the athletic training staff were documented and
categorized as cramping, heat illness/dehydration, muscle tightness, muscle strains, non-contact joint injuries, contact
injuries, and illness. The number of missed practices due to injury/illness was also recorded as well as total injuries.
Data were analyzed using a 2 x 2 Chi-square statistic to examine the incidence of reported first time cramping and injury
occurrences for creatine users and non-users (p<0.05).
Table 1. First Time Injuries of NCAA Division I Baseball Players During Training and
Competition (Creatine Users & Non Creatine Users)
Creatine Users
(n=21) Non-Creatine Users
(n=18)
Treated Injury
*Injuries No Injuries *Injuries No Injuries
Cramping 4 17 8 10
Heat/dehydration 0 21 0 18
Muscle tightness 7 14 11 7
Muscle strains 6 15 10 8
Non-
contact injuries
5 16 7 11
Contact injuries 9 12 8 10
Illness 8 13 7 11
Missed practices 6 15 6 12
Players lost season
0 21 2 16
Total injuries 45 123 59 96
*Number of first time injuries for creatine and non-creatine users.
Creatine Supplementation, Cramping and Injury in Baseball
19
RESULTS
Only first time injuries were included in the Chi-square procedure in order to adhere to the nonparametric statistical
assumption of mutual exclusiveness even though select athletes were treated for different/multiple/reoccurring injuries
throughout the course of the study. If an athlete aggravated a previous injury (i.e., sprained ankle) that occurred before
the season it was not recorded for the purposes of this study and there were no multi-sport athletes in the study. Results
of this study revealed that creatine-users had significantly fewer total injuries, ?2 (1)=4.69, p=0.03 than non-creatine users.
However, there were no significant differences between groups regarding cramping, ?2 (1)=2.94, p=0.08, muscle tightness,
?2 (1)=3.01, p=0.08, muscle strains, ?2 (1)=2.92, p=0.08, non-contact joint injuries, ?2 (1)=1.04, p=0.31, contact injuries, ?2
(1)=0.009, p=0.92, illness, ?2 (1)=002, p=0.95, missed practices due to injury, ?2 (1)=0.103, p=0.74, and players lost for the
season, ?2 (1)=2.45, p=0.11. Furthermore, no detrimental events caused by heat stress or dehydration were reported by
either group.
DISCUSSION
Anecdotal reports have suggested that creatine supplementation may promote dehydration, cramping, and
musculoskeletal injury (2,4,38,40). Since many of these reports have emanated from certified athletic trainers and
coaches, they are commonly reported as side effects from creatine supplementation (2,4,40). As a result, some certified
athletic trainers and coaches have restricted availability of creatine to their athletes (particularly during intense training
periods performed in the heat) and some have warned against the use of creatine until more long-term data
demonstrates its safety. In addition, some athletic organizations (e.g., NCAA) have banned teams from “providing”
creatine to their athletes citing safety and fairness issues, although athletes are still allowed to take creatine. Results of the
present study indicated that creatine use among Division I baseball players training and competing in very hot and humid
environments does not appear to increase the incidence of dehydration, cramping, and/or muscle injury in comparison to
athletes who do not take creatine. Moreover, that the athletes’ did not report a consistent pattern of perceived
negative side effects as a result of the creatine supplementation protocol. Within the scope of this study, these findings
add to the growing body of evidence indicating that creatine supplementation apparently does not increase the incidence
of anecdotally reported detrimental side effects and/or cause unknown health problems (10,13,14,18,33-35).
One of the most commonly reported anecdotal side effects associated with creatine supplementation has been that
creatine may increase the incidence of dehydration, muscle cramping, and/or decrease heat tolerance. In this regard,
some have suggested that since creatine supplementation may increase work capacity, athletes who take creatine during
training in hot and humid environments may experience a greater rate of dehydration, muscle cramping, and/or heat
illness (40). Another theory suggests that since creatine has been suggested to promote fluid retention, it may alter
electrolyte status and thereby promote muscle cramping by interfering with the muscle’s contraction/relaxation
mechanisms (2,4,40). Over the last few years, a number of studies have examined the effects of creatine
supplementation on hydration status, electrolyte levels, and dehydration during exercise performed in the heat (20-
23,41-43). Results of these studies have indicated that creatine does not promote dehydration, alter electrolyte levels,
or increase thermal stress. In addition, there has been no evidence that creatine supplementation promotes muscle
cramping among athletes (21,23,37,44-50). In fact, recent studies have indicated that creatine supplementation may
actually promote hydration (21,23,41), reduce thermal stress during exercise in the heat (23,42), and/or possible reduce
the incidence of injury based on occurrence rates (11,17,31,33,37,44-47,49-52). The results of our study suggest that
the incidence of cramping and dehydration observed among creatine users was lower or proportional to non-users.
Creatine Supplementation, Cramping and Injury in Baseball
20
Anecdotal reports have also suggested that creatine may promote a higher incidence of muscle injuries such as muscle
strains and pulls (2,4,40). Proponents of this theory have postulated that since creatine supplementation may promote
rapid increases in strength and body mass, the athlete may be more predisposed to additional stress placed on muscles,
bones, joints, ligaments, and connective tissues. Results of our investigation indicate that the incidence of muscle
tightness, muscle strains, non-contact injuries, and contact injuries among creatine users were similar or lower than the
non-users. There was also no evidence of a greater proportion of individual injuries (e.g., hamstring pulls, groin strains,
etc). Moreover, the incidence of missed practices, players lost with a season ending injury, and total injuries observed
were similar or lower than non-users. If creatine supplementation increased the incidence of these problems, the
incidence of injury in creatine users should have been markedly higher than the nonusers. Yet, the incidence of injury
among athletes who took creatine during training was similar or lower than the athletes not taking creatine. It could be
speculated that creatine supplementation may have allowed the athletes to tolerate training to a greater degree and
thereby lessened the incidence of injury, or simply that creatine has no causal effect on the injuries documented in the
present study. These findings are similar to recent reports that creatine supplementation during training may lessen injury
rates among athletes (11,17,31,33,37,44-47,49-52) and/or hasten recovery following immobilization injury (32).
In summary, the results of this study indicate that college baseball players ingesting creatine during training and
competition had fewer incidences of dehydration, cramping, and or injury than college baseball players not taking
creatine. Although athletes who take creatine during intense training may experience some of these problems, it appears
that the incidence of these problems is lower than athletes not taking creatine. Therefore, these findings may help to
dispel anecdotal myths suggesting that creatine supplementation may increase the prevalence of dehydration, cramping
and/or injury among athletes. Further, it is hoped that these findings may help professionals involved in the training
and/or medical supervision of athletes (i.e., athletic coaches, certified athletic trainers, researchers, certified strength &
conditioning coaches, nutritional consultants, administrators, athletic governing bodies) to better examine the methods
employed to train and/or manage athletes (i.e., over-training in extreme climates, exhaustive conditioning drills, hydration
practices, etc). In this regard, it appears that the type and conditions that athletes are asked to train and/or compete in
may place them at a greater risk of dehydration, cramping and/or injury than anecdotally associating these problems with
creatine supplementation.
ACKNOWLEDGMENTS
We would like to thank the athletes who participated in this study and the coaches who allowed us to conduct this
investigation. A special thanks goes to the athletic training staff for their participation in this study. The investigators
independently collected, analyzed and interpreted data from this study and have no commercial, proprietary, or financial
interest in the outcome of results reported. Presentation of the results in this study does not constitute endorsement by
authors or their institutions of the supplement investigated.
Current address for M. Greenwood, PhD, CSCS*D, R.B. Kreider, PhD, EPC and L. Greenwood, PhD, ATC is The
Exercise & Sport Nutrition Laboratory, Department of Health, Human Performance & Recreation Center for Exercise,
Nutrition, Preventive Health, Research, Baylor University, P.O. Box 97313 Waco, TX 76798-7313. Current address for
Darryn Willoughby is Department of Kinesiology, Texas Christian University, PO Box 297730, Fort Worth TX 76129.
Current address for Allyn Byars is Human Performance Laboratory, Department of PE, Hardin-Simmons University,
Abilene TX 79698. Address correspondence to: Mike Greenwood, PhD, CSCS*D.
Address for correspondence: Michael Greenwood, P.O. Box 97313, Department of HHPR, Baylor University,
Waco, TX 76798; Phone: (254) 710-7687; FAX: (254) 710-3527; Email: Mike_Greenwood@baylor.edu
REFERENCES
Creatine Supplementation, Cramping and Injury in Baseball
21
1. Williams MH, Kreider R, Branch JD. Creatine: The Power Supplement. Champaign, IL: Human Kinetics
Publishers, 1999.
2. Kreider R. Creatine supplementation: analysis of ergogenic value, medical safety, and concerns. J Exerc
Physiol Online 1998;1:7-18. Available at http://www.css.edu/users/tboone2/asep/jan3.htm. Accessed November
27, 2001.
3. Kraemer WJ, Volek JS. Creatine supplementation: its role in human performance. Clin Sports Med
1999;18:651-666, ix.
4. Terjung RL, Clarkson P, Eichner ER, Greenhaff PL, Hespel PJ, Israel RG, et al. American College of Sports
Medicine roundtable. The physiological and health effects of oral creatine supplementation. Med Sci Sports Exerc
2000;32:706-717.
5. Vandenberghe K, Goris M, Van Hecke P, Van Leemputte M, Vangerven L, Hespel P. Long-term creatine
intake is beneficial to muscle performance during resistance training. J Appl Physiol 1997;83:2055-2063.
6. Guerrero-Ontiveros ML, Wallimann T. Creatine supplementation in health and disease. Effects of chronic
creatine ingestion in vivo: down-regulation of the expression of creatine transporter isoforms in skeletal muscle. Mol
Cell Biochem 1998;84:427-437.
7. Tarnopolsky MA, Parise G, Fu MH, Brose A, Mahoney D, Wallimann T. Creatine monohydrate
supplementation at the recommended dosage does not affect creatine transporter content during resistance exercise
training in either the young or the elderly. Presented at the 6th Internationl Conference on Guanidino Compounds in
Biology and Medicine; September 3, 2001; Cincinatti, OH.
8. Kuehl K, Soehler S, Kulacki K, Goldberg L, Elliot D, Bennett W, et al. Effects of oral creatine monohydrate
supplementation on renal function in adults. Med Sci Sports Exerc 2000;32:S168.
9. Kreider R, Ransom J, Rasmussen C, Hunt J, Melton C, Stroud T, et al. Creatine supplementation during pre-
season football training does not affect markers of renal function. FASEB J 1999;13:A543.
10. Kreider R, Melton C, Rasmussen C, Greenwood M, Lancaster S, Cantler E, et al. Effects of long-term
creatine supplementation on renal function and muscle & liver enzyme efflux. Med Sci Sports Exerc 2001;33:S207.
11. Rasmussen C, Kreider R, Melton C, Ransom J, Stroud T, Cantler E, et al. Long-term creatine supplementation
during football training does not affect markers of renal stress. J Strength Cond Res 1999;13:431.
12. Almada AL, Kreider R, Melton C, Rasmussen C, Lundberg J, Ransom J, et al. Long-term creatine
supplementation does not affect markers of renal stress in athletes. J Strength Cond Res 2000;14:359.
13. Robinson TM, Sewell DA, Casey A, Steenge G, Greenhaff PL. Dietary creatine supplementation does not
affect some haematological indices, or indices of muscle damage and hepatic and renal function. Br J Sports Med
2000;34:284-288.
14. Poortmans JR, Francaux M. Long-term oral creatine supplementation does not impair renal function in healthy
athletes. Med Sci Sports Exerc 1999;31:1108-1110.
15. Poortmans JR, Auquier H, Renaut V, Durussel A, Saugy M, Brisson GR. Effect of short-term creatine
supplementation on renal responses in men. Eur J Appl Physiol Occup Physiol 1997;76:566-567.
16. Ransom J, Kreider R, Hunt J, Melton C, Rasmussen C, Stroud T, et al. Effects of creatine supplementation
during training on markers of catabolism and muscle & liver enzymes. Med Sci Sports Exerc 1999;31:S265.
17. Ransom J, Kreider R, Rasmussen C, Melton C, Stroud T, Cantler E, et al. Effects of long-term creatine
supplementation during training on markers of catabolism and enzyme efflux. J Str Cond Res 1999;13:431.
18. Schilling BK, Stone MH, Utter A, Kearney JT, Johnson M, Coglianese R, et al. Creatine supplementation and
health variables: a retrospective study. Med Sci Sports Exerc 2001;33:183-188.
19. Kreider RB, Ferreira M, Wilson M, Grindstaff P, Plisk S, Reinardy J, et al. Effects of creatine supplementation
on body composition, strength, and sprint performance. Med Sci Sports Exerc 1998;30:73-82.
Creatine Supplementation, Cramping and Injury in Baseball
22
20. Rasmussen C, Kreider R, Ransom J, Hunt J, Melton C, Stroud T, et al. Creatine supplementation during pre-
season football training does not affect fluid or electrolyte status. Med Sci Sports Exerc 1999;31:S299.
21. Hulver MW, Campbell A, Haff G, Schroeder C, Comeau M, Potteiger JA. The effects of creatine
supplementation on total body fluids, performance, and muscle cramping during exercise. Med Sci Sports Exerc
2000;32:S133.
22. Oopik V, Paasuke M, Timpmann S, Medijainen L, Ereline J, Smirnova T. Effect of creatine supplementation
during rapid body mass reduction on metabolism and isokinetic muscle performance capacity. Eur J Appl Physiol
Occup Physiol 1998;78:83-92.
23. Volek JS, Mazzetti SA, Farquhar WB, Barnes BR, Gomez, Al, Kraemer WJ. Physiological responses to
short-term exercise in the heat after creatine loading. Med Sci Sports Exerc 2001;33:1101-1108.
24. Mihic S, MacDonald JR, McKenzie S, Tarnopolsky MA. Acute creatine loading increases fat-free mass, but
does not affect blood pressure, plasma creatinine, or CK activity in men and women. Med Sci Sports Exerc
2000;32:291-296.
25. Peeters BM, Lantz CD, Mayhew JL: Effect of oral creatine monohydrate and creatine phosphate
supplementation on maximal strength indices, body composition, and blood pressure. J Strength Cond Res
1999;13:3-9.
26. Earnest CP, Snell P, Rodriguez R, Almada A, Mitchell TL. The effect of creatine monohyerate ingestion on
anaerobic power indices, muscular strength and body composition. Acta Physiol Scand 1995;153:207-209.
27. Earnest CP, Almada A, Mitchell TL. High-performance capillary electrophoresis-pure creatine monohydrate
reduced blood lipids in men and women. Clinical Science 1996;91:113-118.
28. Bemben MG, Bemben DA, Loftiss DD, Knehans AW. Creatine supplementation during resistance training in
college football athletes. Med Sci Sports Exerc 2001;33:1667-1673.
29. Bermon S, Venembre P, Sachet C, Valour S, Dolisi C. Effects of creatine monohydrate ingestion in sedentary
and weight- trained older adults. Acta Physiol Scand 1998;164:147-155.
30. Eijnde BO, Hespel P. Short-term creatine supplementation does not alter the hormonal response to resistance
training. Med Sci Sports Exerc 2001;33:449-453.
31. Greenwood M, Kreider R, Melton C, Rasmussen C, Lundberg J, Stroud T, et al. Short- and long-term
creatine supplementation does not affect hematological markers of health. J Strength Cond Res 2000;14:362-363.
32. Hespel P, Eijnde BO, Van Leemputte M, Urso B, Greenhaff PL, Labarque V, et al. Oral creatine
supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in
humans. J Physiol 2001;536:625-633.
33. Kreider R, Rasmussen C, Melton C, Greenwood M, Stroud T, Ransom J, et al. Long-term creatine
supplementation does not adversely affect clinical markers of health. Med Sci Sports Exerc 2000;32:S134.
34. Stone MH, Schilling BK, Fry AC, Johnson M, Keith RE, Kearney JT, et al. A retrospective study of long-term
creatine supplementation on blood markers of health. J Strength Cond Res 1999;3:433
35. Sipila I, Rapola J, Simell O, Vannas A. Supplementary creatine as a treatment fo gyrate atrophy of the choroid
and retina. New Engl J Med 1981;304:867-870.
36. Vannas-Sulonen K, Sipila I, Vannas A, Simell O, Rapola J. Gyrate atrophy of the choroid and retina. A five-
year follow-up of creatine supplementation. Ophthalmology 1985;92:1719-1727.
37. Greenwood M, Farris J, Kreider R, Greenwood L, Byars A. Creatine supplementation patterns and perceived
effects in select division I collegiate athletes. Clin J Sport Med 2000;10:191-194.
38. Juhn MS, O'Kane JW, Vinci DM. Oral creatine supplementation in male collegiate athletes: a survey of dosing
habits and side effects. J Am Diet Assoc 1999;99:593-595.
39. LaBotz M, Smith BW. Creatine supplement use in an NCAA Division I athletic program. Clin J Sport Med
1999;9:167-169.
Creatine Supplementation, Cramping and Injury in Baseball
23
40. Juhn MS, Tarnopolsky M. Potential side effects of oral creatine supplementation: a critical review. Clin J
Sport Med 1998;8:298-304.
41. Ziegenfuss TN, Lowery, LM, and Lemon, PWR. Acute fluid volume changes in men during three days of
creatine supplementation. Journal of Exercise Physiology Online 1998;1:1-9. Available at
http://www.css.edu/users/tboone2/asep/jan3.htm. Accessed November 27, 2001.
42. Kern M, Podewils LJ, Vukovich M, Buono MJ. Physiological response to exercise in the heat following
creatine supplementation. Journal of Exercise Physiology Online 2001;4:18-27, 2001. Available at
http://www.css.edu/users/tboone2/asep/Kern.pdf. Accessed November 27, 2001.
43. Papadopoulos C, Imamura R, Bandon LJ. The effect of creatine supplementation on repeated bouts of high-
intensity exercise in the heat. Med Sci Sports Exerc 2001;33:S203.
44. Greenwood M, Kreider R, Rasmussen C, Ransom J, Melton C, Stroud T, et al. Creatine supplementation
does not increase incidence of cramping or injury during college football training II. J Strength Cond Res
1999;13:425-426.
45. Greenwood M, Greenwood LD, Kreider R, Byars A. Effects of creatine supplementation on the incidence of
cramping/injury during college football three a day training. Med Sci Sports Exerc 2000;32:S136.
46. Greenwood LD, Greenwood M, Kreider R, Byars A. Effects of creatine supplementation on the incidence of
cramping/injury during collegiate fall baseball. Med Sci Sports Exerc 2000;32:S136.
47. Hunt J, Kreider R, Melton C, Ransom J, Rasmussen C, Stroud T, et al. Creatine does not increase incidence
of cramping or injury during pre-season college football training II. Med Sci Sports Exerc 1999;31:S355.
48. Kreider R, Rasmussen C, Ransom J, Almada AL. Effects of creatine supplementation during training on the
incidence of muscle cramping, injuries and GI distress. J Strength Cond Res 1998;12:275.
49. Kreider R, Melton C, Ransom J, Rasmussen C, Stroud T, Cantler E, et al. Creatine supplementation does not
increase incidence of cramping or injury during college football training I. J Strength Cond Res 1999;13:428.
50. Kreider R, Melton C, Hunt J, Rasmussen C, Ransom J, Stroud T, et al. Creatine does not increase incidence
of cramping or injury during pre-season college football training I. Med Sci Sports Exerc 1999;31:S355.
51. Ortega Gallo PA, Dimeo F, Batista J, Bazan F, Betchakian L, Garcia Cambon C, et al. Creatine
supplementation in soccer players, effects in body composition and incidence of sport-related injuries. Med Sci Sports
Exerc 2000;32:S134.
52. Greenwood M, Kreider R, Greenwood LD, Comeau M, Brown LE, Stahura K, et al. Perceived health status
and side-effects associated with creatine supplementation during the collegiate baseball season. Med Sci Sports &
Exerc 2001;33:S205.
... Several open-label trials of the effects of creatine supplementation on muscle cramps, muscle tightness, muscle strains, injuries (contact and non-contact), missed practices, and players lost for the season in collegiate athletes have been published. In comparison with non-creatine users, creatine users experienced fewer muscle cramps, tightness, strains, and total injuries in 72 collegiate football players, [141] fewer total injuries but no differences in other variables in 39 collegiate baseball players [142], and fewer muscle cramps but no differences in other variables in 130 collegiate football players [143]. In these three studies, creatine ingestion was typical of high-dose loading followed by low-dose maintenance supplementation protocols and lasted from one to three seasons. ...
... These data indicate that, in hard-training athletes, creatine may reduce the likelihood of muscle injury and dysfunction. The effects of creatine supplementation on muscle injury and muscle dysfunction are summarized in Table 2 [141][142][143]. ...
Article
Full-text available
Exertional (exercise-induced) rhabdomyolysis is a potentially life threatening condition that has been the subject of research, intense discussion, and media attention. The causes of rhabdomyolysis are numerous and can include direct muscle injury, unaccustomed exercise, ischemia, extreme temperatures, electrolyte abnormalities, endocrinologic conditions, genetic disorders, autoimmune disorders, infections, drugs, toxins, and venoms. The objective of this article is to review the literature on exertional rhabdomyolysis, identify precipitating factors, and examine the role of the dietary supplement creatine monohydrate. PubMed and SPORTDiscus databases were searched using the terms rhabdomyolysis, muscle damage, creatine, creatine supplementation, creatine monohydrate, and phosphocreatine. Additionally, the references of papers identified through this search were examined for relevant studies. A meta-analysis was not performed. Although the prevalence of rhabdomyolysis is low, instances still occur where exercise is improperly prescribed or used as punishment, or incomplete medical history is taken, and exertional rhabdomyolysis occurs. Creatine monohydrate does not appear to be a precipitating factor for exertional rhabdomyolysis. Healthcare professionals should be able to recognize the basic signs of exertional rhabdomyolysis so prompt treatment can be administered. For the risk of rhabdomyolysis to remain low, exercise testing and prescription must be properly conducted based on professional standards.
... However, this is not supported by the literature. The results of several studies show no increase or decrease in muscle cramps, tightness, strains, total injuries, missed practices, or players lost for the season in collegiate athletes ingesting creatine supplements [30][31][32]. Interestingly, even though anecdotal reports claim that creatine supplements exacerbate muscle dysfunction, several research teams have investigated creatine supplementation as a means to enhance recovery from intense exercise by reducing exercise-induced muscle damage [33][34][35]. ...
Article
Full-text available
Numerous health conditions affecting the musculoskeletal, cardiopulmonary, and nervous systems can result in physical dysfunction, impaired performance, muscle weakness, and disuse-induced atrophy. Due to its well-documented anabolic potential, creatine monohydrate has been investigated as a supplemental agent to mitigate the loss of muscle mass and function in a variety of acute and chronic conditions. A review of the literature was conducted to assess the current state of knowledge regarding the effects of creatine supplementation on rehabilitation from immobilization and injury, neurodegenerative diseases, cardiopulmonary disease, and other muscular disorders. Several of the findings are encouraging, showcasing creatine’s potential efficacy as a supplemental agent via preservation of muscle mass, strength, and physical function; however, the results are not consistent. For multiple diseases, only a few creatine studies with small sample sizes have been published, making it difficult to draw definitive conclusions. Rationale for discordant findings is further complicated by differences in disease pathologies, intervention protocols, creatine dosing and duration, and patient population. While creatine supplementation demonstrates promise as a therapeutic aid, more research is needed to fill gaps in knowledge within medical rehabilitation.
... The gains in muscle mass appear to be a result of an improved ability to perform high intensity exercise enabling an athlete to train harder and thereby promote greater training adaptations and muscle hypertrophy [72][73][74][75]. The only clinically significant side effect occasionally reported from creatine monohydrate supplementation has been the potential for weight gain [71,[76][77][78] Although concerns have been raised about the safety and possible side effects of creatine supplementation [79,80], recent longterm safety studies have reported no apparent side effects [78,81,82] and/or that creatine monohydrate may lessen the incidence of injury during training [83][84][85]. Additionally a recent review was published which addresses some of the concerns and myths surrounding creatine monohydrate supplementation [86]. Consequently, supplementing the diet with creatine monohydrate and/or creatine containing formulations seems to be a safe and effective method to increase muscle mass. ...
Article
Full-text available
Abstract Sport nutrition is a constantly evolving field with literally thousands of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper presents a well-referenced overview of the current state of the science related to how to optimize training through nutrition. More specifically, this article discusses: 1.) how to evaluate the scientific merit of nutritional supplements; 2.) general nutritional strategies to optimize performance and enhance recovery; and, 3.) our current understanding of the available science behind weight gain, weight loss, and performance enhancement supplements. Our hope is that ISSN members find this review useful in their daily practice and consultation with their clients.
Article
Without question, since its over the counter availability to consumers in 1992, creatine has become one of the most popular nutritional supplements among exercise and sport populations. In addition to its popularity, creatine has become one of the most extensively studied and research validated products that have been experimentally dissected in a multitude of ways. Specifically, investigators have evaluated topics such as muscle-creatine content and phosphocreatine resynthesis, short-and long-term ergogenic effects of creatine ingestion, gender issues associated with creatine ingestion, age-specific issues related to creatine ingestion, ethical considerations of creatine ingestion, viable clinical and medical applications of creatine ingestion, health and safety concerns regarding creatine ingestion, and more recently relevant biochemical mechanisms regarding the creatine transport system. Although each of these research approaches have greatly contributed to the body of creatine literature, it is first imperative to grasp various foundational aspects associated with understanding this controversial nutritional supplement. With these considerations in mind, the purpose of this chapter is to set the stage for a creatine overview regarding the following information: (1) creatine facts, fallacies, and safety (2) creatine quality, purity, and formulations, (3) creatine dosage protocols, (4) creatine nutritional supplement combinations, (5) foundational creatine ergogenic efficacy, (6) future creatine research options, and (7) common creatine practical applications.
Article
This article briefly reviews research on the topic of creatine supplementation with special reference to Issues of relevance for competitive weightlifters.The article is aimed at weightlifters and their coaches to Increase their knowledge of the supplement in a manner specifically relating to their sport. Recommendations are made regarding creatine's specific effect on weightlifting performance, suitable loading practices for weightlifters, and supplementation's effect in body weight maintenance.
Article
Full-text available
The road to a safe, effective, and enjoyable fitness and athletic lifestyle should be considered an ultramarathon and not a 100-meter sprint. The often quoted phrase that Rome was not built in one day really holds credence here because of the number of annual exercisers that initiate an exercise protocol only to quit within a few weeks because they did not attain the desired results in their specified time frame. Because of inappropriate dietary habits and or training protocols that lead to overreaching (short-term) and overtraining (long-term), decrements of physiologic and psychologic outcomes occur in many exercisers (Kreider et al. In: Kreider et al., eds. Overtraining in Sport. Champaign, IL: Human Kinetics Publishers; 1 998:vii-ix). Whereas intense training is necessary to optimize performance, intense training over prolonged periods can hinder performance. The truth of the matter is, although it may take a person 30 or 40 years to display their current physical fitness state, it is human nature to want to immediately become, although unrealistic, the next Mr. or Ms. Olympia overnight. Yes, an effective athletic or fitness lifestyle becomes a journey and not a weekend vacation that involves the development of knowledge, patience, proper nutritional practices, variety, commitment and tenacity, not to mention hard work, in order for a person to reach and maintain their optimal athletic/exercise/fitness goals. Although research supports a plethora of reasons why people abandon exercise protocols (Weinberg and Gould. Foundations of Sport and Exercise Psychology. Champaign, IL: Human Kinetics Publishers; 1999:371-395), the scientific literature has varied on the precise reasons why and how the processes of overreaching/overtraining occur and can be reduced or eliminated. With these elements in mind, the purpose of this chapter is to present the following information: 1) physiologic and psychologic effects of overtraining related to sport and exercise, 2) valid fitness and health assessment guidelines to limit aspects of overtraining, 3) strength and conditioning periodization design to reduce occurrences of overtraining, and 4) scientific-based nutritional strategies to promote and prevent overtraining with exercise and sport populations.
Article
Creatine remains one of the most extensively studied nutritional ergogenic aids available for athletes. Hundreds of studies have reported that increasing muscle creatine stores through creatine supplementation can augment muscle creatine content, improve exercise and training adaptations, and/or provide some therapeutic benefit to some clinical populations. Consequently, creatine represents one of the most effective and popular nutritional ergogenic aids available for athletes. The future of creatine research is very promising. Researchers are attempting to determine ways to maximize creatine storage in the muscle, which types of exercise may obtain the greatest benefit from creatine supplementation, the potential medical uses of creatine, and the long-term safety and efficacy of creatine supplementation. Among these, the most promising area of research is determining the potential medical uses of creatine, particularly in patients with creatine synthesis deficiencies and neuromuscular diseases. Nevertheless, in regard to athletes, creatine has continually proved itself to be one of the most effective and safe nutritional supplements to increase strength, muscle mass, and performance. This is despite oftentimes inaccurate and misleading information that has been written about creatine in the popular media over the last several years.
Article
Fueling the rugby athlete requires a sports nutrition plan that balances energy intake with energy output while providing the athlete with adequate fuel for recovery. The content and timing of meals are fundamental parts of a successful regimen and often require the athlete to participate in extensive planning and preparation to succeed. Carbohydrates, protein, and fat are the primary fuel of the rugby athlete's diet, and proper hydration is imperative to optimize performance. The use of dietary supplements such as energy drinks and caffeine are controversial, and the supplementation of vitamins and minerals is generally not recommended. The use of creatine monohydrate as a supplement to a well-balanced diet has been shown to be safe and effective. With the help of sports nutritionists, team physicians, educated athletes, and coaches, a multifactorial all-encompassing plan is required generally to maximize optimal performance on and off the rugby pitch.
Article
summary: This article briefly reviews research on the topic of creatine supplementation with special reference to issues of relevance for competitive weightlifters. The article is aimed at weightlifters and their coaches to increase their knowledge of the supplement in a manner specifically relating to their sport. Recommendations are made regarding creatine's specific effect on weightlifting performance, suitable loading practices for weightlifters, and supplementation's effect in body weight maintenance. (C) 2007 National Strength and Conditioning Association
Article
Full-text available
The literature on creatine supplementation supporting its efficacy has grown rapidly and has included studies in both healthy volunteers and patient populations. However, the first rule in the development of therapeutic agents is safety. Creatine is well-tolerated in most individuals in short-term studies. However, isolated reports suggest creatine may be associated with various side effects affecting several organ systems including skeletal muscle, the kidney and the gastrointestinal tract. The majority of clinical studies fail to find an increased incidence of side effects with creatine supplementation. To date, studies have not found clinically significant deviations from normal values in renal, hepatic, cardiac or muscle function. Few data are available on the long-term consequences of creatine supplementation.
Article
Full-text available
Abstract Well-trained subjects …n ˆ 6† were studied before and after losing a mean 3.0%±4.3% of body mass to determine whether muscle performance could be maintained or even enhanced by dietary creatine sup- plementation. During a 5-day period of loss of mass the subjects were randomly assigned to a creatine or placebo supplemented diet. All the subjects were measured be- fore and after loss of mass on both supplements for isokinetic peak torque (PT) and work at peak torque (WPT) of knee extensors, also for intermittent high in- tensity working capacity of the same muscle group. The latter test consisted of submaximal isokinetic knee ex- tensions at an angular velocity of 1.57 rad á s)1 for 45 s at the rate of 30 contractions each min (submaximal work, Ws max) followed by 15-s maximal e€ort (maximal work, Wmax). Total duration of the test was 3 min. Ha- ematocrit was measured and haemoglobin, ammonia, lactate, glucose and urea concentrations were analysed in blood samples obtained at rest and after cessation of muscle performance tests. The results indicated that creatine supplementation in comparison with placebo treatment during rapid body mass reduction may help to maintain muscle PT and WPT at high angular velocities, not in¯uencing Wmax and the rate of fatigue development during Wmax, but a€ecting adversely Ws max. Within the limitations of the present study the reasons for the partially detrimental e€ect of creatine administration remain obscure, but it is suggested that impaired crea- tine uptake in muscle during body mass loss as well as creatine induced changes in muscle glucose and glycogen metabolism may be involved
Article
Purpose: Long-term safety of creatine supplementation has been questioned. This retrospective study was performed to examine markers related to health, the incidence of reported side effects and the perceived training benefits in athletes supplementing with creatine monohydrate. Methods: Twenty-six athletes (18 M and 8 F, 24.7 +/- 9.2 y; 82.4 +/- 20.0 kg; 176.5 +/- 8.8 cm) from various sports were used as subjects. Blood was collected between 7:00 and 8:30 a.m. after a 12-h fast. Standard clinical examination was performed for CBC and 27 blood chemistries. Testosterone, cortisol, and growth hormone were analyzed using an ELISA. Subjects answered a questionnaire on dietary habits, creatine supplementation, medical history, training history, and perceived effects of supplementation. Body mass was measured using a medical scale, body composition was estimated using skinfolds, and resting heart rate and blood pressure were recorded. Subjects were grouped by supplementation length or no use: Gp1 (control) = no use (N = 7; 3 F, 4 M); Gp2 = 0.8-1.0 yr (N = 9; 2 F, 7 M); and Gp3 = 1(+) (N = 10; 3 F, 7 M). Results: Creatine supplementation ranged from 0.8--4 yr. Mean loading dose for Gp2 and Gp3 was 13.7 +/- 10.0 and the maintenance dose was 9.7 +/- 5.7 g.d(-)1. Group differences were analyzed using one-way ANOVA. Conclusions: Expected gender differences were observed. Of the comparisons made among supplementation groups, only two differences for creatinine and total protein (P < 0.05) were noted. All group means fell within normal clinical ranges. There were no differences in the reported incidence of muscle injury, cramps, or other side effects. These data suggest that long-term creatine supplementation does not result in adverse health effects.
Article
The use of creatine as an ergogenic aid for athletic performance is growing in popularity, despite limited scientific support for its efficacy. The purpose of this study was to determine the effect of creatine (Cr) monohydrate (CrM) and creatine phosphate (CrP) supplementation on strength, body composition, and blood pressure over a 6-week period. Thirty-five males (age range = 19-29 years) with at least 2 years of strength training experience were tested on three separate occasions (pretest, 3 weeks, 6 weeks). Strength tests performed were the one-repetition maximum (1-RM) bench press, 1-RM leg press, and maximal repetitions on the seated preacher bar curl with a fixed amount of weight. Subjects were divided into three groups matched for strength: placebo (Pl), CrM, and CrP. All subjects were provided a standardized strength training regimen and ingested a loading dosage of 20 g per day for the first 3 days of the study, followed by a maintenance dose of 10 g per day for the remainder of the 6-week supplementation period. Significant differences were noted between the Pl group and the two Cr groups for changes in lean body mass, body weight, and 1-RM bench press. These results suggest that oral Cr supplementation will result in greater strength and fat-free mass development. In addition, CrP may be as effective as CrM in achieving these desired outcomes. (C) 1999 National Strength and Conditioning Association