Cramping and Injury Incidence in Collegiate Football Players Are Reduced by Creatine Supplementation

OBJECTIVE: To examine the effects of creatine supplementation on the incidence of cramping and injury observed during 1 season of National Collegiate Athletic Association Division IA football training and competition. DESIGN AND SETTING: In an open-label manner, subjects who volunteered to take creatine ingested 0.3 g.kg(-1).d(-1) of creatine for 5 days followed by an average of 0.03 g.kg.(-1)d(-1) after workouts, practices, and games. Creatine intake was monitored and recorded by researchers throughout the course of the study. SUBJECTS: Thirty-eight of 72 athletes (53.0%) participating in the 1999 Division IA collegiate football season from the same university volunteered to take creatine in this study. Subjects trained, practiced, or played in environmental conditions ranging from 15 degrees C to 37 degrees C (mean = 27.26 degrees +/- 10.93 degrees C) and 46.0% to 91.0% relative humidity (mean = 54.17% +/- 9.71%). MEASUREMENTS: Injuries treated by the athletic training staff were recorded and categorized as cramping, heat illness or dehydration, muscle tightness, muscle strains, noncontact joint injuries, contact injuries, and illness. The number of missed practices due to injury and illness was also recorded. Data were analyzed using a 2 x 2 chi(2) test to examine the first reported incidences of cramping and injury for creatine users and nonusers. RESULTS: Creatine users had significantly less cramping (chi(2)(1) = 5.35 P =.021); heat illness or dehydration (chi(2)(1) = 4.09, P =.043); muscle tightness (chi(2)(1) = 5.39, P =.020); muscle strains (chi(2)(1) = 5.36, P =.021); and total injuries (chi(2)(1) = 17.80, P<.001) than nonusers. There were no significant differences between groups regarding noncontact joint injuries (chi(2)(1)= 3.48, P =.062); contact injuries (chi(2)(1) = 0.00, P =.100); illness (chi(2)(1) = 6.82, P =.409); missed practices due to injury (chi(2)(1) = 1.43, P =.233); or players lost for the season (chi(2)(1) = 4.75, P =.491). CONCLUSIONS: The incidence of cramping or injury in Division IA football players was significantly lower or proportional for creatine users compared with nonusers.     

Creatine Kinase Levels are Elevated During 2-A-Day Practices in Collegiate Football Players

OBJECTIVE: To determine blood serum creatine kinase (CK) levels in football players undergoing 2-a-day football practices and to determine if CK levels are related to fitness. Our hypotheses were that CK levels in each subject would increase over the course of practices and that higher levels of fitness would result in smaller increases in CK. DESIGN AND SETTING: Creatine kinase measurements were taken 4 times over 10 days of preseason, 2-a-day practices: before beginning practices (CKM1) and on the mornings of the 4th (CKM2), 7th (CKM3), and 10th (CKM4) days of practice. SUBJECTS: Twelve male Division I football players from a midwestern university. MEASUREMENTS: Fitness tests included percentage of body fat, body mass index, anaerobic capacity, and peak power from a 1-leg step test and 1-repetition maximum bench press and squat lifts. Changes in CK levels were calculated as the difference between the second CK measure (CKM2) and the first CK measure (CKM1). RESULTS: Differences were significant between the CK measurements (P =.0002). Post hoc analysis revealed that CKM2 and CKM3 levels were statistically higher than CKM1 levels. No other statistically significant differences between CK measures were noted. Pearson product moment correlation coefficients showed that athletes who generated higher peak power during a 15-second step test had smaller increases in CK levels from CMK1 to CMK2 (r = -.64). Although the correlations with anaerobic capacity (r = -.54, P =.071), body mass index (r = -.51, P =.090), and percentage of body fat (r = -.52, P =.082) approached statistical significance, no other correlations were statistically significant. The mean CKM2 level was 5124.7 U.L(-1) +/- 5518.1, approximately 30 times the norm for men. CONCLUSIONS: Participation in 2-a-day football practices resulted in significant serum CK elevations, which remained elevated for at least 7 days. Participants who had higher peak power had smaller increases in CK.     

Creatine supplementation improves muscular performance in older women

Muscle power and strength decrease with age leading to reduced independence and increased health risk from falls. Creatine supplementation can increase muscle power and strength. The purpose of this study was to examine the effects of 7 days of creatine supplementation on body composition, muscular strength, and lower-body motor functional performance in older women. Thirty 58–71 year old women performed three test sessions (T1–T3) each separated by one week. Each session consisted of one repetition maximum tests for bench press and leg press, and isometric hand-grip, tandem gait, upper-body ergometer, and lower-body ergometer tests. Following T2, subjects were assigned to a creatine monohydrate (0.3 g kg body mass⁻¹ for 7 days) (CR: 63.31 ± 1.22 year, 160.00 ± 1.58 cm, 67.11 ± 4.38 kg) or a placebo (PL: 62.98 ± 1.11 year, 162.25 ± 2.09 cm, 67.84 ± 3.90 kg) supplementation group. CR significantly (P < 0.05) increased bench press (1.7 ± 0.4 kg), leg press (5.2 ± 1.8 kg), body mass (0.49 ± 0.04 kg) and fat free mass (0.52 ± 0.05) and decreased completion time on the functional tandem gait tests from T2–T3. No significant changes were found for PL on any of the measured variables. No adverse side-effects were reported by either group. Short-term creatine supplementation resulted in an increase in strength, power, and lower-body motor functional performance in older women without any adverse side effects     

Effects of creatine monohydrate ingestion in sedentary and weight-trained older adults

To investigate the effects of an oral creatine supplementation in older adults, 32 elderly subjects (67–80 years; 16 females, 16 males) were randomly assigned to four equivalent subgroups (control-creatine; control-placebo; trained-creatine; trained-placebo) based on whether or not they took part in an 8-week strength training programme and an 8-week oral creatine monohydrate creatine supplementation programme. The strength training programme consisted of three sets of eight repetitions at 80% of one-repetition maximum, for leg press, leg extension and chest press, 3 days a week. The 52-day supplementation programme consisted of 20 g of creatine monohydrate (or glucose) and 8 g of glucose per day for the initial 5 days followed by 3 g of creatine monohydrate (or glucose), and 2 g of glucose per day. Prior to and after the training and supplementation periods, body mass, body fat, lower limb muscular volume, 1-, 12-repetitions maxima and isometric intermittent endurance tests for leg press, leg extension and chest press were determined. In all groups, no significant changes in anthropometric parameters were observed. For all movements, the increases in 1- and 12-repetitions maxima were greater (P < 0.02) in trained than control subjects. No significant interactions (supplementation/training/time) were observed for the 1-, 12-repetitions maxima, and the isometric intermittent endurance, whatever the movement considered. We conclude that oral creatine supplementation does not provide additional benefits for body composition, maximal dynamical strength, and dynamical and isometric endurances of healthy elderly subjects, whether or not it is associated with an effective strength training.     

The effects of creatine supplementation on muscular performance and body composition responses to short-term resistance training overreaching

To determine the effects of creatine supplementation during short-term resistance training overreaching on performance, body composition, and resting hormone concentrations, 17 men were randomly assigned to supplement with 0.3 g/kg per day of creatine monohydrate (CrM: n=9) or placebo (P: n=8) while performing resistance exercise (5 days/week for 4 weeks) followed by a 2-week taper phase. Maximal squat and bench press and explosive power in the bench press were reduced during the initial weeks of training in P but not CrM. Explosive power in the bench press, body mass, and lean body mass (LBM) in the legs were augmented to a greater extent in CrM (P0.05) by the end of the 6-week period. A tendency for greater 1-RM squat improvement (P=0.09) was also observed in CrM. Total testosterone (TT) and the free androgen index (TT/SHBG) decreased in CrM and P, reaching a nadir at week 3, whereas sex hormone binding globulin (SHBG) responded in an opposite direction. Cortisol significantly increased after week 1 in CrM (+29%), and returned to baseline at week 2. Insulin was significantly depressed at week 1 (–24%) and drifted back toward baseline during weeks 2–4. Growth hormone and IGF-I levels were not affected. Therefore, some measures of muscular performance and body composition are enhanced to a greater extent following the rebound phase of short-term resistance training overreaching with creatine supplementation and these changes are not related to changes in circulating hormone concentrations obtained in the resting, postabsorptive state. In addition, creatine supplementation appears to be effective for maintaining muscular performance during the initial phase of high-volume resistance training overreaching that otherwise results in small performance decrements.     

Identification of Cardiometabolic Risk Among Collegiate Football Players

Context:

Excessive fat mass clearly has adverse effects on metabolic processes that can ultimately lead to the development of chronic disease. Early identification of high-risk status may facilitate referral for definitive diagnostic tests and implementation of interventions to reduce cardiometabolic risk.

Objective:

To document the prevalence of metabolic syndrome among collegiate football players and to develop a clinical prediction rule that does not require blood analysis to identify players who may possess a high level of cardiometabolic risk.

Design:

Cross-sectional cohort study.

Setting:

University athletic training research laboratory.

Patients or Other Participants:

Sixty-two National Collegiate Athletic Association Division I Football Championship Subdivision football players (age  =  19.9 ± 1.2 years, height  =  182.6 ± 6.1 cm, mass  =  97.4 ± 18.3 kg).

Main Outcome Measure(s):

Anthropometric characteristics associated with body fat, isokinetic quadriceps strength, and biometric indicators associated with metabolic syndrome were measured. Participants were classified as high risk or low risk for future development of type 2 diabetes and cardiovascular disease.

Results:

The prevalence of metabolic syndrome in the cohort was 19% (12 of 62), and 79% (49 of 62) of the players exceeded the threshold for 1 or more of its 5 components. A 4-factor clinical prediction rule that classified individuals on the basis of waist circumference, blood pressure, quadriceps strength, and ethnic category had 92% sensitivity (95% confidence interval  =  65%, 99%) and 76% specificity (95% confidence interval  =  63%, 86%) for discrimination of high-risk or low-risk status.

Conclusions:

The risk for developing type 2 diabetes and cardiovascular disease appears to be exceptionally high among collegiate football players. A lack of race-specific criteria for the diagnosis of metabolic syndrome almost certainly contributes to an underestimation of the true level of cardiometabolic risk for African American collegiate football players.     

Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution

OBJECTIVE: To examine the effects of oral creatine (Cr) monohydrate supplementation on muscle Cr concentration, body mass, and total body water (TBW), extracellular water (ECW), and intracellular water (ICW) volumes. DESIGN AND SETTING: After an overnight fast, urinary Cr and creatinine concentrations, muscle Cr concentration, body mass, TBW, ECW, and ICW were measured, and subjects were randomly assigned to either a Cr or a placebo (P) group. The Cr group ingested 25 g/d of Cr for 7 days (loading phase) and 5 g/d for the remaining 21 days (maintenance phase), whereas the P group ingested a sucrose P using the same protocol. All the measures were reassessed immediately after the loading and maintenance phases. SUBJECTS: Sixteen men (age = 22.8 +/- 3.01 years, height = 179.8 +/- 7.1 cm, body mass = 84.8 +/- 11.2 kg) and 16 women (age = 21.8 +/- 2.51 years, height = 163.4 +/- 5.9 cm, body mass = 63.6 +/- 14.0 kg) involved in resistance training volunteered to participate in this study. MEASUREMENTS: Muscle Cr concentration was determined from the vastus lateralis muscle using a percutaneous needle-biopsy technique. Total body water, ECW, and ICW volumes were assessed using deuterium oxide and sodium bromide dilution analyses. RESULTS: The Cr group experienced a significant increase in muscle Cr concentration, body mass, and TBW. The P group experienced a small but significant increase in TBW only. CONCLUSIONS: The Cr supplementation protocol was effective for increasing muscle Cr concentrations, body mass, and TBW; however, fluid distribution was not changed.     

Predicting football players' dual-energy x-ray absorptiometry body composition using standard anthropometric measures

Context:

The recent increase in athlete size, particularly in football athletes of all levels, coupled with the increased health risk associated with obesity warrants continued monitoring of body composition from a health perspective in this population. Equations developed to predict percentage of body fat (%Fat) have been shown to be population specific and might not be accurate for football athletes.

Objective:

To develop multiple regression equations using standard anthropometric measurements to estimate dual-energy x-ray absorptiometry %Fat (DEXA%Fat) in collegiate football players.

Design:

Controlled laboratory study.

Patients and Other Participants:

One hundred fifty-seven National Collegiate Athletic Association Division IA football athletes (age  =  20 ± 1 years, height  =  185.6 ± 6.5 cm, mass  =  103.1 ± 20.4 kg, DEXA%Fat  =  19.5 ± 9.1%) participated.

Main Outcome Measure(s):

Participants had the following measures: (1) body composition testing with dual-energy x-ray absorptiometry; (2) skinfold measurements in millimeters, including chest, triceps, subscapular, midaxillary, suprailiac, abdominal (SFAB), and thigh; and (3) standard circumference measurements in centimeters, including ankle, calf, thigh, hip (AHIP), waist, umbilical (AUMB), chest, wrist, forearm, arm, and neck. Regression analysis and fit statistics were used to determine the relationship between DEXA%Fat and each skinfold thickness, sum of all skinfold measures (SFSUM), and individual circumference measures.

Results:

Statistical analysis resulted in the development of 3 equations to predict DEXA%Fat: model 1, (0.178 • AHIP) + (0.097 • AUMB) + (0.089 • SFSUM) − 19.641; model 2, (0.193 • AHIP) + (0.133 • AUMB) + (0.371 • SFAB) − 23.0523; and model 3, (0.132 • SFSUM) + 3.530. The R² values were 0.94 for model 1, 0.93 for model 2, and 0.91 for model 3 (for all, P < .001).

Conclusions:

The equations developed provide an accurate way to assess DEXA%Fat in collegiate football players using standard anthropometric measures so athletic trainers and coaches can monitor these athletes at increased health risk due to increased size.     

Long-term creatine supplementation improves muscular performance during resistance training in older women

This study examined the effects of long-term creatine supplementation combined with resistance training (RT) on the one-repetition maximum (1RM) strength, motor functional performance (e.g., 30-s chair stand, arm curl, and getting up from lying on the floor tests) and body composition (e.g., fat-free mass, muscle mass, and % body fat using DEXA scans) in older women. Eighteen healthy women (64.9 ± 5.0 years) were randomly assigned in a double-blind fashion to either a creatine (CR, N = 9) or placebo (PL, N = 9) group. Both groups underwent a 12-week RT program (3 days week^?1), consuming an equivalent amount of either creatine (5.0 g day^?1) or placebo (maltodextrin). After 12 week, the CR group experienced a greater (P < 0.05) increase (Δ%) in training volume (+164.2), and 1RM bench press (+5.1), knee extension (+3.9) and biceps curl (+8.8) performance than the PL group. Furthermore, CR group gained significantly more fat-free mass (+3.2) and muscle mass (+2.8) and were more efficient in performing submaximal-strength functional tests than the PL group. No changes (P > 0.05) in body mass or % body fat were observed from pre- to post-test in either group. These results indicate that long-term creatine supplementation combined with RT improves the ability to perform submaximal-strength functional tasks and promotes a greater increase in maximal strength, fat-free mass and muscle mass in older women.     

Effects of creatine monohydrate supplementation during combined strength and high intensity rowing training on performance.

This study investigated the effect of creatine monohydrate (Cr) supplementation on performance and training volume in rowers. Twenty-two rowers trained with continuous and interval rowing and resistance training 4 and 2 days/week, respectively, for 6 weeks. Cr supplementation consisted of a 5-day load (0.3 g/kg(-1) x day(-1)) followed by a 5-week maintenance dose (0.03 g/kg(-1) x day(-1)) while training. Five days of Cr loading did not change body composition, repeated interval rowing performance, 2,000-m rowing times, or strength performance. Five additional weeks of training with a maintenance dose of Cr or placebo significantly improved body composition, VO2max, 2,000-m rowing times, repeated power interval performance, and strength to a similar extent in both groups. Subjects training with Cr did not perform more repetitions per set of strength exercise nor produce or maintain higher power outputs during repeated rowing sessions. Cr supplementation did not increase performance or training volume over a placebo condition in rowers that performed a combined high intensity rowing and strength program.     

Collegiate Football Players Display More Active Cervical Spine Mobility Than High School Football Players

OBJECTIVES: To compare the active cervical spine range of motion and resting cervical spine alignment (sagittal plane) of collegiate and high school football players using the Cervical Range of Motion (CROM) Measurement System and to identify normative values for these populations. DESIGN AND SETTING: A 2 x 7 factorial design for main effects was used to evaluate the influence of level of play (college, high school) on the cervical spine range of motion of football players. Data were collected during preparticipation physical examinations. SUBJECTS: A convenience sample of 189 unimpaired collegiate (n = 70, age = 19.5 +/- 1.5 years) and high school (n = 119, age = 15.7 +/- 1.4 years) football players participated. MEASUREMENTS: Subjects were measured for active cervical spine range of motion using the CROM system and the manufacturer's recommended measurement techniques. RESULTS: Collegiate football players had increased active cervical spine range of motion for flexion, extension, left cervical rotation, and left lateral flexion (overall mean increase = 4.3 +/- 2 degrees ) compared with high school players. Collegiate players also assumed a more flexed resting sagittal-plane cervical spine posture (P =.001). CONCLUSIONS: Collegiate players generally displayed greater active cervical spine range of motion than high school players. The increased resting sagittal-plane cervical spine flexion alignment we report among the collegiate players suggests a change in the natural cervical spine lordosis, possibly due to a neutral-zone shift associated with combined increases in lower cervical spine flexion and upper cervical spine extension as an adaptation to football training or playing. Further study using radiographic or magnetic resonance imaging techniques is warranted. The CROM system is a useful tool for identifying aggregate hypomobile or hypermobile active cervical spine mobility among football players that might otherwise remain unrecognized during standard preparticipation physical examinations. In combination with manual segmental assessments of passive accessory intervertebral movements, CROM enables early identification of players with impaired or excessive cervical spine mobility, thus facilitating proactive injury-prevention intervention.     

Creatine supplementation post-exercise does not enhance training-induced adaptations in middle to older aged males

Purpose

The present study evaluated the effects of creatine monohydrate (CrM) consumption post-exercise on body composition and muscle strength in middle to older males following a 12-week resistance training program.

Methods

In a double-blind, randomized trial, 20 males aged between 55 and 70 years were randomly assigned to consume either CrM-carbohydrate (CHO) [20 g days^?1 CrM + 5 g days^?1 CHO × 7 days, then 0.1 g kg^?1 CrM + 5 g CHO on training days (average dosage of ~8.8 g)] or placebo CHO (20 g days^?1 CHO × 7 days, then 5 g CHO on training days) while participating in a high intensity resistance training program [3 sets × 10 repetitions at 75 % of 1 repetition maximum (1RM)], 3 days weeks^?1 for 12 weeks. Following the initial 7-day “loading” phase, participants were instructed to ingest their supplement within 60 min post-exercise. Body composition and muscle strength measurements, blood collection and vastus lateralis muscle biopsy were completed at 0, 4, 8 and 12 weeks of the supplement and resistance training program.

Results

A significant time effect was observed for 1RM bench press (p = 0.016), leg press (p = 0.012), body mass (p = 0.03), fat-free mass (p = 0.005) and total myofibrillar protein (p = 0.005). A trend for larger muscle fiber cross-sectional area in the type II fibers compared to type I fibers was observed following the 12-week resistance training (p = 0.08). No supplement interaction effects were observed.

Conclusion

Post-exercise ingestion of creatine monohydrate does not provide greater enhancement of body composition and muscle strength compared to resistance training alone in middle to older males.     

Creatine supplementation reduces increased homocysteine concentration induced by acute exercise in rats

The aim of this study was to evaluate the effect of creatine supplementation on homocysteine (Hcy) metabolism after acute aerobic and anaerobic exercise. A total of 112 Wistar rats were divided into four groups: aerobic exercise (A), aerobic exercise plus creatine supplementation (ACr), anaerobic exercise (An), and anaerobic exercise plus creatine-supplemented (AnCr). Creatine supplementation consisted of the addition of 2% creatine monohydrate to the diet. After 28 days, the rats performed an acute moderate aerobic exercise bout (1 h swimming with 4% of total body weight load) or an acute intense anaerobic exercise bout (6 × 30-s vertical jumps into the water with a 30-s rest between jumps, with 50% of total body weight load). The animals were killed before (pre) and at 0, 2, and 6 h (n = 8) after acute exercise. Plasma Hcy concentration increased significantly (P < 0.05) up to 2 h after anaerobic exercise (An group: pre 8.7 ± 1.2, 0 h 13.2 ± 2.3, 2 h 13.5 ± 4.2, and 6 h 12.1 ± 2.2, μmol/l). The same did not occur in acute aerobic exercised animals. Nevertheless, creatine supplementation significant decreased (P < 0.05) homocysteine concentration independent of exercise intensity (AnCr group: pre 17%, 0 h 80%, 2 h 107%, and 6 h 48%; ACr group: pre 17%, 0 h 19%, 2 h 28%, and 6 h 27%). Increased S-adenosylhomocysteine was also found in the An group. In conclusion, acute intense anaerobic exercise increased plasma Hcy concentration. On the other hand, creatine supplementation decreased plasma Hcy independent of exercise intensity.     

Creatine supplementation, sleep deprivation, cortisol, melatonin and behavior

The effect of creatine supplementation and sleep deprivation, with intermittent moderate-intensity exercise, on cognitive and psychomotor performance, mood state, effort and salivary concentrations of cortisol and melatonin were examined. Subjects were divided into a creatine supplementation group and a placebo group. They took 5 g of creatine monohydrate or a placebo, dependent on their group, four times a day for 7 days immediately prior to the experiment. They undertook tests examining central executive functioning, short-term memory, choice reaction time, balance, mood state and effort at baseline and following 18-, 24- and 36-h sleep deprivation, with moderate intermittent exercise. Saliva samples were taken prior to each set of tests. A group x time analysis of covariance, with baseline performance the covariate, showed that the creatine group performed significantly (p < 0.05) better than the placebo group on the central executive task but only at 36 h. The creatine group demonstrated a significant (p < 0.01) linear improvement in performance of the central executive task throughout the experiment, while the placebo group showed no significant effects. There were no significant differences between the groups for any of the other variables. A significant (p < 0.001) main effect of time was found for the balance test with a linear improvement being registered. Cortisol concentrations on Day 1 were significantly (p < 0.01) higher than on Day 2. Mood significantly (p < 0.001) deteriorated up to 24 h with no change from 24 to 36 h. Effort at baseline was significantly (p < 0.01) lower than in the other conditions. It was concluded that, during sleep deprivation with moderate-intensity exercise, creatine supplementation only affects performance of complex central executive tasks.     

Creatine supplementation does not enhance submaximal aerobic training adaptations in healthy young men and women

The benefits of dietary creatine supplementation on muscle performance are generally related to an increase in muscle phosphocreatine content. However, creatine supplementation may benefit endurance sports through increased glycogen re-synthesis following exercise. This study investigated the effect of creatine supplementation on muscle glycogen content, submaximal exercise fuel utilisation and endurance performance following 4 weeks of endurance training. Thirteen healthy, physically active, non-vegetarian subjects volunteered to take part and completed the study. Subjects were supplemented with either creatine monohydrate (CREAT, n = 7) or placebo-maltodextrin (CON, n = 6). Submaximal fuel utilisation and endurance performance were assessed before and after a 4 week endurance training program. Muscle biopsies were also collected before and following training for assessment of muscle creatine and glycogen content. Training increased quadriceps glycogen content to the same degree (∼20%) in both groups (P = 0.04). There was a significant training effect on submaximal fuel utilisation and improved endurance performance. However, there was no significant treatment effect of creatine supplementation. Creatine supplementation does not effect metabolic adaptations to endurance training.     

Financial resources for conducting athletic training programs in the collegiate and high school settings

The distribution of resources to athletic training programs varies greatly, depending on the size and scope of the athletic program. No research has been found that assesses the differences in dollars allocated within various athletic training settings or assesses whether the different program levels allocate similar proportions of their resources to like categories of expenditures. In this study, I assessed the financial resources available to athletic training programs at major football NCAA Division IA schools, small football NCAA Division IA schools, NCAA Division IAA schools, NCAA Division II schools, NCAA Division III schools, and high schools. All schools had men's and women's sports and football programs. Categories assessed included: size and scope of the athletic program, supplies and equipment, operating expenses, medical expenses, salaries and benefits, malpractice insurance, and use of competitive bids in purchasing. Data supported the conclusion of wide disparities within many categories and in total expenses. Large-scale football NCAA Division IA programs spent $925.86 per athlete, while NCAA Division III programs spent $181.22, and high school programs spent $95.62. However, athletic trainers at all levels are conducting athletic training programs governed by the same professional competencies and standards of care.     

Hierarchical differences in body composition of professional Sumo wrestlers

The body composition of 36 professional Sumo wrestlers and 39 collegiate male students were assessed densitometrically. The means of body weight, BMI and %fat for Sumo wrestlers were 117.1 kg, 36.5 and 26.2%, extraordinarily large compared with untrained men (p < 0.001). Results of the analysis of variance of divisions of Sumo wrestlers revealed significant differences in body weight, fat-free mass, fat mass, BMI, fat-free mass index (FFM/height2) and fat mass index (FM/height2). For the visual expression of the hierarchical differences of body composition, fat mass index and fat-free mass index of the wrestlers in various leagues were plotted on a body composition chart. Wrestlers in the Sekitori division had significantly larger fat-free mass index scores in comparison with wrestlers from the lower divisions who share a common area of the chart. The cut-off point of fat-free mass index which divided Sekitori wrestlers from other wrestlers is approximately 30 and this value may be one of the anthropometrical indications of whether or not a Sumo wrestler is destined to be successful.     

Elevated Anterior Compartment Pressure in the Leg After Creatine Supplementation: A Controlled Case Report

OBJECTIVE: To report abnormal changes in lower leg anterior compartment pressure in 1 subject who consumed creatine as a dietary supplement. BACKGROUND: The subject received creatine at a dosage of 0.3 g.kg body mass(-1).d(-1) for 6 days, followed by 0.03 g.kg body mass(-1).d(-1) for 28 days. Thereafter, the subject consumed no supplement for 21 days. Compartment pressure was measured pre-exercise and for 15 minutes postexercise after a treadmill run for 20 minutes at 80% of VO(2) max before supplementation and after 6 and 34 days of supplementation. DIFFERENTIAL DIAGNOSIS: Normally, resting anterior compartment pressure is less than 15 mm Hg, whereas postexercise pressure is below 30 to 35 mm Hg. Creatine supplementation for 6 days dramatically increased pressure at rest (31 mm Hg) and at 1 minute (67 mm Hg), 5 minutes (35 mm Hg), 10 minutes (28 mm Hg), and 15 minutes (26 mm Hg) postexercise. Pressure remained high at rest (35 mm Hg) and at 1 minute (109 mm Hg), 5 minutes (90 mm Hg), 10 minutes (87 mm Hg), and 15 minutes (69 mm Hg) postexercise after 34 days of supplementation. TREATMENT: The subject stopped taking creatine for 21 days. Compartment pressure was measured at rest and after exercise after 7 and 21 days with no supplementation. Anterior compartment pressure decreased after cessation of creatine supplementation. However, pressures were elevated at 7 days postsupplementation at rest (26 mm Hg) and at 1 minute (112 mm Hg), 5 minutes (58 mm Hg), 10 minutes (40 mm Hg), and 15 minutes (30 mm Hg) postexercise. Pressures at 21 days postsupplementation remained high at rest (24 mm Hg) and at 1 minute (64 mm Hg), 5 minutes (42 mm Hg), 10 minutes (27 mm Hg), and 15 minutes (27 mm Hg) postexercise. CONCLUSION: These data indicate that creatine supplementation can substantially increase anterior compartment pressure in the leg.     

Creatine supplementation exacerbates allergic lung inflammation and airway remodeling in mice

Creatine supplement is the most popular nutritional supplement, and has various metabolic functions and sports medicine applications. Creatine supplementation increases muscle mass and can decrease muscular inflammation. Some studies have also suggested a beneficial role of creatine supplementation on chronic pulmonary diseases such as chronic obstructive pulmonary disease and cystic fibrosis. Among athletes, the prevalence of asthma is high, and many of these individuals may be taking creatine. However, the effects of creatine supplementation on chronic pulmonary diseases of allergic origin have not been investigated. In the present study, we analyzed the effects of creatine supplementation on a model of chronic allergic lung inflammation. Thirty-one Balb/c mice were divided into four groups: control, creatine (Cr), ovalbumin (OVA), and OVA+Cr. OVA and OVA+Cr groups were sensitized with intraperitoneal injections of OVA on Days 0, 14, 28, and 42. OVA challenge (OVA 1%) and Cr treatment (0.5 g/kg/d) were initiated on Day 21 and lasted until Day 53. We determined the index of hyperresponsiveness, the serum levels of OVA-specific immunoglobulin (Ig)E and IgG(1), and the total and differential cell counts in bronchoalveolar lavage fluid. We also quantified airway inflammation, and the airway density of IL-4+, IL-5+, IL-2+, IFN-gamma+, and insulin-like growth factor (IGF)-1+ cells, collagen and elastic fibers, and airway smooth muscle thickness. Our results showed that creatine in OVA-sensitized mice increased hyperresponsiveness; eosinophilic inflammation; airway density of IL-4+, IL-5+, and IGF-1 inflammatory cells; airway collagen and elastin content; and smooth muscle thickness. The results show that creatine supplementation exacerbates the lung allergic response to OVA through a T helper cell type 2 pathway and increased IGF-1 expression.     

A systematic review of prophylactic braces in the prevention of knee ligament injuries in collegiate football players

OBJECTIVE: To determine the relative risk reduction associated with prophylactic knee braces in the prevention of knee injuries in collegiate football players. DATA SOURCES: An exhaustive search for original research was performed using the PubMed, SportDiscus, and CINAHL databases from 1970 through November 2006, with the search terms knee brace, knee braces, knee bracing and football, prophylactic brace, and prophylactic knee braces. STUDY SELECTION: Seven studies comparing knee injuries among braced and nonbraced collegiate football players were included. Study methods were assessed using the Physiotherapy Evidence Database (PEDro) scale. PEDro scores ranged from 2 to 5. DATA EXTRACTION: The number of participants and frequency of knee injuries were used to calculate the relative risk reduction or increase. DATA SYNTHESIS: We found a relative risk reduction for 3 studies with point estimates of 10% (36% to -26%), 58% (25% to 76%), and 56% (13% to 77%). Four studies demonstrated an increased risk of injury, with point estimates of 17% (19% to -71%), 49% (-31% to -69%), 114% (23% to -492%), and 42% (-18% to -70%). CONCLUSIONS: Data from existing research are inconsistent. Based on a Strength of Recommendation Taxonomy level of evidence of 2 with a grade B recommendation, we cannot conclusively advocate or discourage the use of prophylactic knee braces in the prevention of knee injuries in collegiate football players.