Differential Effects of Continuous Versus Discontinuous Aerobic Training on Blood Pressure and Hemodynamics.

Landram, MJ, Utter, AC, Baldari, C, Guidetti, L, McAnulty, SR, and Collier, SR. Differential effects of continuous versus discontinuous aerobic training on blood pressure and hemodynamics. J Strength Cond Res 32(1): 97-104, 2018-The purpose of this study was to compare the hemodynamic, arterial stiffness, and blood flow changes after 4 weeks of either continuous or discontinuous aerobic exercise in adults. Forty-seven subjects between the ages of 18 and 57 were recruited for 1 month of either continuous aerobic treadmill work for 30 minutes at 70% max heart rate or 3 bouts of 10 minutes of exercise at 70% of max heart rate with two 10 minutes break periods in between, totaling 30 minutes of aerobic work. After exercise, both continuous (CON) and discontinuous (DIS) groups demonstrated a significant improvement in maximal oxygen uptake (V[Combining Dot Above]O2max, CON 35.39 ± 1.99 to 38.19 ± 2.03; DIS 36.18 ± 1.82 to 39.33 ± 1.75), heart rate maximum (CON 183.5 ± 3.11 to 187.17 ± 3.06; DIS 179.06 ± 2.75 to 182 ± 2.61), decreases in systolic blood pressure (CON 119 ± 1.82 to 115.11 ± 1.50; DIS 117.44 ± 1.90 to 112.67 ± 1.66), diastolic blood pressure (CON 72.56 ± 1.65 to 70.56 ± 1.06; DIS 71.56 ± 1.59 to 69.56 ± 1.43), augmentation index (CON 17.17 ± 2.17 to 14.9 ± 1.92; DIS 19.71 ± 2.66 to 13.91 ± 2.46), central pulse wave velocity (CON 8.29 ± 0.32 to 6.92 ± 0.21; DIS 7.85 ± 0.30 to 6.83 ± 0.29), peripheral pulse wave velocity (CON 9.49 ± 0.35 to 7.72 ± 0.38; DIS 9.11 ± 0.37 to 7.58 ± 0.47), and significant increases in average forearm blood flow (CON 4.06 ± 0.12 to 4.34 ± 0.136; DIS 4.26 ± 0.18 to 4.53 ± 0.15), peak forearm blood flow (FBF) after reactive hyperemia (CON 28.45 ± 0.094 to 29.96 ± 0.45; DIS 29.29 ± 0.46 to 30.6 ± 0.38), area under the curve (AUC) of FBF (CON 28.65 ± 1.77 to 30.4 ± 1.08; DIS 30.52 ± 1.9 to 31.67 ± 1.44), and AUC peak FBF after reactive hyperemia (CON 222.3 ± 5.68 to 231.95 ± 4.42; DIS 230.81 ± 6.91 to 237.19 ± 5.39). These data suggest that for healthy people either 4 weeks of continuous or discontinuous aerobic training is effective in improving measures of fitness and vascular health.

Validity of Urine Specific Gravity When Compared With Plasma Osmolality as a Measure of Hydration Status in Male and Female NCAA Collegiate Athletes.

Sommerfield, LM, McAnulty, SR, McBride, JM, Zwetsloot, JJ, Austin, MD, Mehlhorn, JD, Calhoun, MC, Young, JO, Haines, TL, and Utter, AC. Validity of urine specific gravity when compared with plasma osmolality as a measure of hydration status in male and female NCAA collegiate athletes. J Strength Cond Res 30(8): 2219-2225, 2016-The purpose of this study was to evaluate the response of urine specific gravity (Usg) and urine osmolality (Uosm) when compared with plasma osmolality (Posm) from euhydration to 3% dehydration and then a 2-hour rehydration period in male and female collegiate athletes. Fifty-six National Collegiate Athletic Association (NCAA) wrestlers (mean ± SEM); height 1.75 ± 0.01 m, age 19.3 ± 0.2 years, and body mass (BM) 78.1 ± 1.8 kg and 26 NCAA women's soccer athletes; height 1.64 ± 0.01 m, age 19.8 ± 0.3 years, and BM 62.2 ± 1.2 kg were evaluated. Hydration status was obtained by measuring changes in Posm, Uosm, Usg, and BM. Male and female subjects dehydrated to achieve an average BM loss of 2.9 ± 0.09% and 1.9 ± 0.03%, respectively. Using the medical diagnostic decision model, the sensitivity of Usg was high in both the hydrated and dehydrated state for males (92%) and females (80%). However, the specificity of Usg was low in both the hydrated and dehydrated states for males (10 and 6%, respectively) and females (29 and 40%, respectively). No significant correlations were found between Usg and Posm during either the hydrated or dehydrated state for males or females. Based on these results, the use of Usg as a field measure of hydration status in male and female collegiate athletes should be used with caution. Considering that athletes deal with hydration status on a regular basis, the reported low specificity of Usg suggests that athletes could be incorrectly classified leading to the unnecessary loss of competition.

Acute Sodium Ingestion Before Exercise Increases Voluntary Water Consumption Resulting In Preexercise Hyperhydration and Improvement in Exercise Performance in the Heat.

Dehydration has been shown to hinder performance of sustained exercise in the heat. Consuming fluids before exercise can result in hyperhydration, delay the onset of dehydration during exercise and improve exercise performance. However, humans normally drink only in response to thirst, which does not result in hyperhydration. Thirst and voluntary fluid consumption have been shown to increase following oral ingestion or infusion of sodium into the bloodstream. We measured the effects of acute sodium ingestion on voluntary water consumption and retention during a 2-hr hydration period before exercise. Subjects then performed a 60-min submaximal dehydration ride (DR) followed immediately by a 200 kJ performance time trial (PTT) in a warm (30 °C) environment. Water consumption and retention during the hydration period was greater following sodium ingestion (1380 ± 580 mL consumed, 821 ± 367 ml retained) compared with placebo (815 ± 483 ml consumed, 244 ± 402 mL retained) and no treatment (782 ± 454 ml consumed, 148 ± 289 mL retained). Dehydration levels following the DR were significantly less after sodium ingestion (0.7 ± 0.6%) compared with placebo (1.3 ± 0.7%) and no treatment (1.6 ± 0.4%). Time to complete the PTT was significantly less following sodium consumption (773 ± 158 s) compared with placebo (851 ± 156 s) and no treatment (872 ± 190 s). These results suggest that voluntary hyperhydration can be induced by acute consumption of sodium and has a favorable effect on hydration status and performance during subsequent exercise in the heat.

Effect of cluster set configurations on power clean technique.

The purpose of this investigation was to examine the effects of cluster set configurations on power clean technique. Ten male, recreational weightlifters performed three sets of six repetitions at 80% of one repetition max with 0 (P0), 20 (P20) or 40 seconds (P40) inter-repetition rest. During the first and second set of P0, the catch and first pull were in a more forward position during repetition 6 as compared to repetition 1, respectively. During the second set of P40, differences in horizontal displacement were found between repetitions 1 and 6 for the second pull and the loop. During the third set of P40, differences in horizontal displacement were found between repetitions 1 and 6 for the first pull, transition, and beginning of the second pull. No differences in horizontal displacement were found between repetitions 1 and 6 during P20. During each set of P0, vertical displacement decreased between repetitions 1 and 6 (1.02 ± 0.07 m vs. 0.94 ± 0.06 m; Mean ± s). Cluster set configurations led to the maintenance of vertical displacement throughout all sets. The results demonstrate cluster set configurations with greater than 20 seconds inter-repetition rest maintain weightlifting technique to a greater extent than a traditional set configuration.

Dehydration and acute weight gain in mixed martial arts fighters before competition.

The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters before competition. Urinary measures of hydration status and body mass were determined approximately 24 hours before and then again approximately 2 hours before competition in 40 MMA fighters (mean ± SE, age: 25.2 ± 0.65 years, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). The AWG was defined as the amount of body weight the fighters gained in the approximately 22-hour period between the official weigh-in and the actual competition. On average, the MMA fighters gained 3.40 ± 2.2 kg or 4.4% of their body weight in the approximately 22-hour period before competition. Urine specific gravity significantly decreased (p < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the approximately 22-hour rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of >1.021 immediately before competition indicating significant or serious dehydration. The MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24-hour period before competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating before competition and subsequently are competing in a dehydrated state. Weight management guidelines to prevent acute dehydration in MMA fighters are warranted to prevent unnecessary adverse health events secondary to dehydration.

Validity of COSMED's quark CPET mixing chamber system in evaluating energy metabolism during aerobic exercise in healthy male adults.

This study validated the accuracy of COSMED's Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system in measuring metabolic factors during maximal, graded exercise testing. Subjects included 32 physically active men between the ages of 18 and 34 years. During the first test session, subjects were measured for maximal oxygen consumption twice (15 min separation) with the CPET and Douglas bag systems (random order). During the second test session, subjects exercised through four stages of the Bruce treadmill protocol with measurement by the CPET and Douglas bag systems (random order) during steady state at the end of each 3-minute stage. Statistical analysis using a 2 (systems) x 5 (time) repeated measures ANOVA showed that the pattern of change in VO2, VCO2, VE, FeO2, FeCO2, and RER did not differ significantly between CPET and Douglas bag systems. This validation study indicates that the CPET mixing chamber system provides valid metabolic measurements that compare closely with the Douglas bag system during aerobic exercise.

Effect of inter-repetition rest on ratings of perceived exertion during multiple sets of the power clean.

The purpose of this study was to examine the effects of inter-repetition rest (IRR) on ratings of perceived exertion (RPE) in the power clean exercise in a multiple set protocol using peak power as an indication of fatigue. Ten resistance-trained males participated in four testing sessions which consisted of determination of a one repetition maximum (1RM) in the power clean exercise (session 1) and performance of three sets of six repetitions at 80% of 1RM with 0 (P0), 20 (P20), or 40 s (P40) IRR (sessions 2-4). Fatigue during all three conditions was indicated by a significant decrease in power of 9.0% (P0), 3.0% (P20) and 2.1% (P40), respectively. Significant difference in the rate of power decrease in P40 indicates less fatigue in comparison to P0 and P20. P40 resulted in a significantly lower RPE compared to P0 and P20 (7.43 ± 0.34, 6.46 ± 0.47, and 5.30 ± 0.55, respectively). RPE increased significantly (p ≤ 0.01) within each set (5.26 ± 0.37, 6.46 ± 0.44, and 7.46 ± 0.53; sets 1, 2, and 3, respectively). Significant difference in average RPE between the conditions indicates that RPE is not a determinant of intensity (% of 1RM) but the rate of fatigue (decreases in peak power). In addition, the fact that RPE increased between sets 1, 2 and 3 during all conditions support the same conclusion. The results demonstrate that increasing IRR in power clean training decreases the perception of effort and is inversely related to the rate of fatigue.

The validity of multifrequency bioelectrical impedance measures to detect changes in the hydration status of wrestlers during acute dehydration and rehydration.

The objective of this study was to examine the validity of multifrequency direct segmental bioelectrical impedance analysis (DSM-BIA) measures to detect changes in the hydration status of wrestlers after they underwent 3% acute dehydration and a 2-hour rehydration period. Fifty-six National Collegiate Athletic Association wrestlers: (mean ± SEM); age 19.5 ± 0.2 years, height 1.73 ± 0.01 m, and body mass (BM) 82.5 ± 2.3 kg were tested in euhydrated, dehydrated (-3.5%), and 2-hour rehydration conditions using DSM-BIA to detect the changes in hydration status. The hydration status was quantified by measuring the changes in plasma osmolality (P(osm)), urine osmolality (Uosm), urine specific gravity (U(sg)), BM, and weighted segmental impedance at frequencies of 5, 20, 50, 100, and 500 kHz. Weighted segmental impedance significantly increased after a 3.5% reduction in the body weight for all the 5 frequencies evaluated, but it did not return to baseline at 2-hour rehydration. P(osm) (303 ± 0.6 mOsm·L(-1)), Uosm (617 ± 47 mOsm·L(-1)), and U(sg) (1.017 ± 0.001) all significantly increased at postdehydration and returned to baseline at 2-hour rehydration. Estimations of extracellular water were significantly different throughout the trial, but there were no significant changes in the estimations of the total body water or intracellular water. The results of this study demonstrate the potential use of DSM-BIA as a field measure to assess the hydration status of wrestlers for the purpose of minimal weight certification before the competitive season. When employing DSM-BIA to assess the hydration status, the results indicated that the changes in weighted segmental impedance at the frequencies evaluated (5, 20, 50, 100, and 500 kHz) are sensitive to acute changes in dehydration but lag behind changes in the standard physiological (plasma and urinary) markers of hydration status after a 2-hour rehydration period.

Effect of interrepetition rest on power output in the power clean.

The effect of interrepetition rest (IRR) periods on power output during performance of multiple sets of power cleans is unknown. It is possible that IRR periods may attenuate the decrease in power output commonly observed within multiple sets. This may be of benefit for maximizing improvements in power with training. This investigation involved 10 college-aged men with proficiency in weightlifting. The subjects performed 3 sets of 6 repetitions of power cleans at 80% of their 1 repetition maximum with 0 (P0), 20 (P20), or 40 seconds (P40) of IRR. Each protocol (P0, P20, P40) was performed in a randomized order on different days each separated by at least 72 hours. The subjects performed the power cleans while standing on a force plate with 2 linear position transducers attached to the bar. Peak power, force, and velocity were obtained for each repetition and set. Peak power significantly decreased by 15.7% during P0 in comparison with a decrease of 5.5% (R1: 4,303 ± 567 W, R6: 4,055 ± 582 W) during P20 and a decrease of 3.3% (R1: 4,549 ± 659 W, R6: 4,363 ± 476 W) during P40. Peak force significantly decreased by 7.3% (R1: 2,861 ± 247 N, R6: 2,657 ± 225 N) during P0 in comparison with a decrease of 2.7% (R1: 2,811 ± 327 N, R6: 2,730 ± 285 N) during P20 and an increase of 0.4% (R1: 2,861 ± 323 N, R6: 2,862 ± 280 N) during P40. Peak velocity significantly decreased by 10.2% (R1: 1.97 ± 0.15 m·s(-1), R6: 1.79 ± 0.11 m·s(-1)) during P0 in comparison with a decrease of 3.8% (R1: 1.89 ± 0.13 m·s(-1), R6: 1.82 ± 0.12 m·s(-1)) during P20 and a decrease of 1.7% (R1: 1.93 ± 0.17 m·s(-1), R6: 1.89 ± 0.14 m·s(-1)) during P40. The results demonstrate that IRR periods allow for the maintenance of power in the power clean during a multiple set exercise protocol and that this may have implications for improved training adaptations.

Validation of the Italian version of the OMNI Scale of Perceived Exertion in a sample of Italian-speaking adults.

The purpose was to examine whether the translation of verbal descriptors from English to Italian affects the validity of the OMNI Scale of Perceived Exertion. 82 people for whom Italian was the primary language performed an orintation trial and a maximal graded exercise test on a cycle ergometer. Ratings of perceived exertion for the overall body and physiological responses were measured during each exercise stage. Significant correlations were found between perceptual responses of the Italian version of the OMNI Cycle Scale of Perceived Exertion and oxygen uptake, pulmonary ventilation, heart rate, respiratory rate, and respiratory exchange ratio responses to a maximal graded exercise test on a cycle ergometer. These findings indicate that the Italian version of the OMNI Scale of Perceived Exertion gives a valid estimate of effort during cycle ergometer exercise.

Evaluation of ultrasound velocity to assess the hydration status of wrestlers.

The objective of this study was to evaluate the utility of ultrasound velocity (UV) to detect changes in the hydration status of wrestlers after undergoing acute dehydration and a 2-hour rehydration period. Forty-seven NCAA wrestlers (mean+/-SEM); age 19.1+/-0.2 years, height 1.73+/-0.1 m, body mass (BM) 79.4+/-2.4 kg were tested in euhydrated, dehydrated, and a 2-hours rehydrated conditions. Hydration status was quantified by measuring changes in plasma osmolarity (Posm), urine osmolarity (Uosm), urine specific gravity (Usg), and BM. Ultrasound velocity was measured at 1 MHz using 1.5-microsecond duration tone burst in the soleus muscle. Significant changes (p<0.001) in UV during periods of dehydration (BM change=-3.6+/-0.14%) (UV=+2.18 m.s) and rehydration (BM change=+2.8+/-0.12%) (UV=-2.89 m.s) were found. Significant main effects (p<0.001) were also found for Usg, Uosm, and Posm during dehydration. The change in Posm from the 1 to 2-hour rehydration time period significantly correlated to the change in UV during the same time period (r=0.27, p<0.001). This study demonstrates that changes in UV correspond to the changes of Posm, Usg, Uosm, and BM during acute dehydration and rehydration in collegiate wrestlers. The use of ultrasound measures may have potential application as an alternative field-based method to assess the hydration status of collegiate wrestlers although future research is warranted.

Effects of rooibos tea, bottled water, and a carbohydrate beverage on blood and urinary measures of hydration after acute dehydration.

Rooibos tea contains polyphenol antioxidants, including flavonoids and phenolic acids that are potent free radical scavengers and has purported benefits for accelerated rehydration. The objective was to evaluate the effects of three different drinks (rooibos tea, bottled water, and a carbohydrate beverage) on blood and urinary markers of hydration after acute dehydration in collegiate wrestlers. Twenty-three athletes were recruited and followed a randomized, cross-over design with three different study arms comparing the effectiveness of rooibos tea, carbohydrate beverage (6% or 60 grams l(-1)), or bottled water (placebo) in promoting rehydration after a 3% reduction in body mass. Urine specific gravity (U(sg)) urine (U(osm)) and plasma osmolarity (P(osm)), and plasma volume were measured pre- and post dehydration and at 1-h after rehydration. Statistical analyses utilized a 3 (conditions) x 3 (times) repeated measures analysis of variance to test main effects. Significant interaction effects were found for P(osm) and U(osm), both of which remained below basleline after 1-h rehydration in the rooibos tea and water trials. No significant interaction effects were found for either urine U(sg) or plasma volume shift. The findings of this study demonstrate that rooibos tea was no more effective in promoting rehydration than plain water, with significant changes being found for P(osm) and U(osm) in the carbohydrate/electrolyte solution, in collegiate wrestlers after a 3% reduction in body mass and a rehydration period of 1-h when consuming 100% of their body weight loss.

Successive bouts of cycling stimulates genes associated with mitochondrial biogenesis.

Exercise increases mRNA for genes involved in mitochondrial biogenesis and oxidative enzyme capacity. However, little is known about how these genes respond to consecutive bouts of prolonged exercise. We examined the effects of 3 h of intensive cycling performed on three consecutive days on the mRNA associated with mitochondrial biogenesis in trained human subjects. Forty trained cyclists were tested for VO(2max) (54.7 +/- 1.1 ml kg(-1) min(-1)). The subjects cycled at 57% watts(max) for 3 h using their own bicycles on CompuTrainer Pro Model trainers (RacerMate, Seattle, WA) on three consecutive days. Muscle biopsies were obtained from the vastus lateralis pre- and post-exercise on days one and three. Muscle samples were analyzed for mRNA content of peroxisome proliferator receptor gamma coactivator-1 alpha (PGC-1alpha), sirtuin 1 (Sirt-1), cytochrome c, and citrate synthase. Data were analyzed using a 2 (time) x 2 (day) repeated measures ANOVA. Of the mRNA analyzed, the following increased from pre to post 3 h rides: cytochrome c (P = 0.006), citrate synthase (P = 0.03), PGC-1alpha (P < 0.001), and Sirt-1 (P = 0.005). The following mRNA showed significant effects from days one to three: cytochrome c (P < 0.001) and citrate synthase (P = 0.01). These data show that exhaustive cycling performed on three consecutive days resulted in both acute and chronic stimuli for mRNA associated with mitochondrial biogenesis in already trained subjects. This is the first study to illustrate an increase in sirtuin-1 mRNA with acute and chronic exercise. These data contribute to the understanding of mRNA expression during both acute and successive bouts of prolonged exercise.

Effects of commercially formulated water on the hydration status of dehydrated collegiate wrestlers.

The objective of this study was to evaluate the effects of three different drinks (commercially formulated water, bottled water, and a carbohydrate-electrolyte beverage) on blood and urinary markers of hydration after acute dehydration in collegiate wrestlers. Twenty-one athletes were recruited to perform a randomized, crossover study comparing the effectiveness of commercially formulated water, carbohydrate-electrolyte (6% or 60 g L(-1)), or regular bottled water (placebo) in promoting rehydration after a 3% reduction in body mass. Urine specific gravity (U(sg)), urine osmolarity (U(osm)), plasma osmolarity (P(osm)), and plasma volume were measured pre- and post-dehydration and at 1 hour after rehydration. Statistical analyses used a 3 (conditions) x 3 (times) repeated measures analysis of variance. Significant (p < 0.01) interactions were found for P(osm), U(osm), and U(sg). P(osm) returned to baseline levels and U(osm) remained in a lower balance after 1 hour of rehydration in the trials of the commercially formulated water and regular bottled water. No significant interactions were found for plasma volume shift. The findings of this study demonstrate that the commercially formulated water was no more effective in promoting rehydration than either a carbohydrate-electrolyte solution or plain water in collegiate wrestlers after a 3% reduction in body mass and a rehydration period of 1 hour when consuming 100% of their body weight loss.

Quercetin does not affect rating of perceived exertion in athletes during the Western States endurance run.

The purpose of this study was to measure the influence of quercetin supplementation on ratings of perceived exertion in ultramarathon runners competing in the 160-km Western States Endurance Run (WSER). Sixty-three runners were randomized to quercetin (Q) and placebo (P) groups, and under double blinded methods ingested four supplements per day with or without 250 mg quercetin for 3 weeks before the WSER. Thirty-nine of the 63 subjects (quercetin N = 18, placebo N = 21) finished the race. At the completion of exercise ratings of perceived exertion (RPE) were assessed at aid stations located at 40, 90, 125, 150, and 160 km (finish line). The pattern of change in RPE over time was not significantly different between the Q and P groups. Ratings of perceived exertion (RPE) did not significantly increase throughout the race (15.2 +/- 2.9 at 40 km -14.2 +/- 4.0 at 160 km) for both groups combined. Race times were not different between the groups (Q = 26.4 +/- 0.7 h and P = 27.5 +/- 0.6 h). Significant time main effects (p < 0.001) were found for both serum glucose and cortisol throughout the race. Quercetin supplementation for 3 weeks prior to the WSER had no effect on RPE during competitive self-paced ultramarathon running. Ratings of perceived exertion (RPE) did not increase in a linear fashion but instead fluctuated nonmonotonically throughout the self-paced endurance running event.

Evaluation of ultrasound in assessing body composition of high school wrestlers.

PURPOSE: To evaluate the accuracy of ultrasound (ULTRA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state. METHODS: Body composition was determined by ULTRA, HW, and three-site SK in 70 high school wrestlers (mean +/- SD: age, 15.5 +/- 1.5; height, 1.60 +/- 0.08 m; body mass, 65.8 +/- 12.7 kg). For all methods, body density (Db) was converted to percent body fat (%BF) using the Brozek equation. Hydration state was quantified by evaluating urine specific gravity. RESULTS: There were no significant differences for estimated FFM between ULTRA (57.2 +/- 9.7 kg) and HW (57.0 +/- 9.9 kg); however, SK (54.9 +/- 8.8 kg) were significantly different from HW. The standard errors of estimate for FFM with HW as the reference method were 2.40 kg for ULTRA and 2.74 kg for SK. Significant correlations were found for FFM between HW and ULTRA (r = 0.97, P < 0.001) and between HW and SK (r = 0.96, P < 0.001). A systematic bias was found for SK, as the difference between SK and HW significantly correlated with the FFM average of the two methods (r = -0.38, P < 0.001). This systematic bias was not found for ULTRA (r = - 0.07). CONCLUSIONS: This study demonstrates that ULTRA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. ULTRA should be considered as an alternative field-based method of estimating the FFM of high school wrestlers.

The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in US High School Boys' Wrestling (2005-2006 Through 2013-2014) and National Collegiate Athletic Association Men's Wrestling (2004-2005 Through 2013-2014).

CONTEXT: The advent of Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided the acquisition of wrestling injury data. OBJECTIVE: To describe the epidemiology of injuries sustained in high school boys' wrestling in the 2005-2006 through 2013-2014 academic years and collegiate men's wrestling in the 2004-2005 through 2013-2014 academic years using Web-based sports injury surveillance. DESIGN: Descriptive epidemiology study. SETTING: Online injury surveillance from wrestling teams of high school boys (annual average = 100) and collegiate men (annual average = 11). PATIENTS OR OTHER PARTICIPANTS: Male wrestlers who participated in practices and competitions during the 2005-2006 through 2013-2014 academic years in high school or the 2004-2005 through 2013-2014 academic years in college. MAIN OUTCOME MEASURE(S): Athletic trainers collected time-loss (≥24 hours) injuries and exposure data during this time period. Injury rates per 1000 athlete-exposures (AEs), injury rate ratios with 95% confidence intervals, and injury proportions by body site and diagnosis were calculated. RESULTS: The High School Reporting Information Online documented 3376 time-loss injuries during 1 416 314 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 2387 time-loss injuries during 257 297 AEs. The total injury rate was higher in college than in high school (9.28 versus 2.38/1000 AEs; injury rate ratio = 3.89; 95% confidence interval = 3.69, 4.10). In high school, the most commonly injured body parts for both practices and competitions were the head/face (practices = 19.9%, competitions = 21.4%) and shoulder/clavicle (practices = 14.1%, competitions = 21.0%). In college, the most frequently injured body parts for both practices and competitions were the knee (practices = 16.7%, competitions = 30.4%) and head/face (practices = 12.1%, competitions = 14.6%). CONCLUSIONS: Injury rates were higher in collegiate than in high school players, and the types of injuries sustained most often differed. Based on these results, continued study of primary and secondary prevention of injury in wrestlers across levels of competition is warranted.

Quercetin ingestion does not alter cytokine changes in athletes competing in the Western States Endurance Run.

The purpose of this study was to measure the influence of quercetin on plasma cytokines, leukocyte cytokine mRNA, and related variables in ultramarathoners competing in the 160-km Western States Endurance Run (WSER). Sixty-three runners were randomized to quercetin and placebo groups and under double-blinded methods ingested 1000 mg/day quercetin for 3 weeks before the WSER. Thirty-nine of the 63 subjects (n = 18 for quercetin, n = 21 for placebo) finished the race and provided blood samples the morning before the race and 15-30 min postrace. Significant prerace to postrace WSER increases were measured for nine proinflammatory and anti-inflammatory plasma cytokines, cortisol (quercetin = 94%, placebo = 96%), serum C-reactive protein (CRP) (mean +/- SE absolute increase, quercetin = 31.8 +/- 4.2, placebo = 38.2 +/- 5.0 mg/L), and creatine kinase (CK) (quercetin = 21,575 +/- 3,977, placebo = 19,455 +/- 3,969 U/L), with no significant group differences. Interleukin-6 (IL-6) mRNA did not change post-WSER, with a significant decrease measured for leukocyte IL-8 mRNA (0.21 +/- 0.03-fold and 0.25 +/- 0.04-fold change from rest, quercetin and placebo, respectively) and significant increases for IL-1Ra mRNA (1.43 +/- 0.18-fold and 1.40 +/- 0.16-fold change, quercetin and placebo, respectively) and IL-10 mRNA (12.9 +/- 3.9-fold and 17.2 +/- 6.1-fold change, quercetin and placebo, respectively), with no significant differences between groups. In conclusion, quercetin ingestion (1 g/day) by ultramarathon athletes for 3 weeks before a competitive 160-km race significantly increased plasma quercetin levels but failed to attenuate muscle damage, inflammation, increases in plasma cytokine and hormone levels, and alterations in leukocyte cytokine mRNA expression.

Quercetin's influence on exercise-induced changes in plasma cytokines and muscle and leukocyte cytokine mRNA.

Trained male cyclists (n = 40) ingested quercetin (Q; n = 20) (1,000 mg/day) or placebo (P; n = 20) supplements under randomized, double-blinded methods for 3 wk before and during a 3-day period in which subjects cycled for 3 h/day at approximately 57% maximal work rate. Blood samples were collected before and after each exercise session and assayed for plasma IL-6, IL-10, IL-1ra, IL-8, TNF-alpha, and monocyte chemoattractant protein 1, and leukocyte IL-10, IL-8, and IL-1ra mRNA. Muscle biopsies were obtained before and after the first and third exercise sessions and assayed for NF-kappaB and cyclooxygenase-2 (COX-2), IL-6, IL-8, IL-1beta, and TNF-alpha mRNA. Postexercise increases in plasma cytokines did not differ between groups, but the pattern of change over the 3-day exercise period tended to be lower in Q vs. P for IL-8 and TNF-alpha (P = 0.094 for both). mRNA increased significantly postexercise for each cytokine measured in blood leukocyte and muscle samples. Leukocyte IL-8 and IL-10 mRNA were significantly reduced in Q vs. P (interaction effects, P = 0.019 and 0.012, respectively) with no other leukocyte or muscle mRNA group differences. Muscle NF-kappaB did not increase postexercise and did not differ between Q and P. Muscle COX-2 mRNA increased significantly postexercise but did not differ between Q and P. In summary, 1 g/day quercetin supplementation by trained cyclists over a 24-day period diminished postexercise expression of leukocyte IL-8 and IL-10 mRNA, indicating that elevated plasma quercetin levels exerted some effects within the blood compartment. Quercetin did not, however, influence any of the muscle measures, including NF-kappaB content, cytokine mRNA, or COX-2 mRNA expression across a 3-day intensified exercise period.

Carbohydrate attenuates perceived exertion during intermittent exercise and recovery.

PURPOSE: The purpose of this study was to examine the effect of carbohydrate supplementation on differentiated and undifferentiated ratings of perceived exertion (RPE) during prolonged intermittent exercise and recovery. METHODS: Twelve male subjects cycled for 2.0 h at 64% Wmax and 73% V O2peak with 3-min rest intervals interspersed every 10 min (2.6 h of total exercise time, including rest intervals) with placebo (P) or carbohydrate (C) beverages. RPE was assessed during the last minute of each 10-min exercise interval and then every 30 s during the 3-min recovery period. RESULTS: The pattern of change in RPE over time was significantly different between C and P ingestion (P < 0.05), with attenuated RPE responses found for both overall body (O) and legs (L). A significant main effect was found for recovery RPE-O between C and P ingestion (P < 0.05), with attenuated RPE responses found in the later part of the 2-h run. C relative to P ingestion was associated with higher respiratory exchange ratios and plasma levels of glucose and with lower levels of plasma cortisol. CONCLUSIONS: These data indicate that carbohydrate supplementation attenuates perceived exertion during prolonged intermittent exercise and recovery.