Iowa wrestling study: weight loss and urinary profiles of collegiate wrestlers.
ABSTRACT A longitudinal study was conducted with various members of the 1975 University of Iowa NCAA championship wrestling team to determine if excessive weight loss, accompanied by signs of dehydration, occurred at the college level of competition. Body weight changes from September to December indicated a mean loss of 6%, while skinfold totals (6 sites) changed from a mean of 58 mm to 37 mm. During a four-month period, mean weight losses of 10.2, 9.5, 8.0, 7.5 and 7.0 lbs occurred in intervals of 12, 4, 3, 2 and 1 day, respectively. Basal urines analyzed throughout the season usually contained 2-3 times the potassium excreted before the season started. Analyses of urines at various intervals during a 2-day time period prior to weigh-in showed a .003 increase in specific gravity, 160 mosm/1 increase in osmolarity, .10 decrease in pH, 45.3 mEq/1 decrease in Na+ concentration, and a 71.3 mEq/1 increase in K+ concentration which suggested that the wrestlers were dehydrated prior to competition. Total urinary electrolyte loss during the 2 days amounted to 3.7% of estimated total body Na+ stores and 3.0% of total body K+ stores. These data were similar to what had been reported for Iowa high school finalists and indicated that collegiate wrestlers were also competing while in a dehydrated state.
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ABSTRACT: The purpose of this study was to characterize the magnitude of acute weight gain (AWG) and dehydration in mixed martial arts (MMA) fighters prior to competition. Urinary measures of hydration status and body mass were determined ∼24 h prior and then again ∼2 h prior to competition in 40 MMA fighters (Mean ± SE, age: 25.2 ± 0.65 yr, height: 1.77 ± 0.01 m, body mass: 75.8 ± 1.5 kg). AWG was defined as the amount of body weight the fighters gained in the ∼22 h 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 ∼22 h period prior to competition. Urine specific gravity significantly decreased (P < 0.001) from 1.028 ± 0.001 to 1.020 ± 0.001 during the ∼22 h rehydration period. Results demonstrated that 39% of the MMA fighters presented with a Usg of greater than 1.021 immediately prior to competition indicating significant or serious dehydration. MMA fighters undergo significant dehydration and fluctuations in body mass (4.4% avg.) in the 24 h period prior to competition. Urinary measures of hydration status indicate that a significant proportion of MMA fighters are not successfully rehydrating prior to 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.The Journal of Strength and Conditioning Research 02/2013; · 1.80 Impact Factor
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ABSTRACT: Despite worldwide popularity of amateur boxing, research focussed on the physiological demands of the sport is limited. The physiological profile of Senior and Junior England international amateur boxers is presented. A gradual (8 to 21-days) and rapid (0 to 7-days) phase of body weight reduction was evident with 2.2 ± 0.3 % of the 7.0 ± 0. 8 % weight loss occurring over the final 24-hours. An increase in body weight >4% was observed following a recovery period. High urine osmolality values (> 1000 mOsm·kg(-1)) were recorded during training and competition. High post-competition blood lactate values (>13.5 mmol·l(-1)) highlighted the need for a well-developed anaerobic capacity and the importance of not entering the ring in a glycogen depleted state. The aerobic challenge of competition was demonstrated by maximum heart rate values being recorded during 'Open' sparring. Mean body fat values of 9-10% were similar to those reported for other weight classified athletes. Normal resting values were reported for hematocrit (Senior 48 ± 2 % and Junior 45 ± 2 %), haemoglobin (Senior 14.7 ± 1.0 g·dl(-1) and Junior 14.5 ± 0.8 g·dl(-1)), bilirubin (Senior 15.3 ± 6.2 µmol·l-1(-1)) and ferritin (Senior 63.3 ± 45.7 ng·ml(-1)). No symptoms associated with asthma or exercise-induced asthma was evident. A well- developed aerobic capacity was reflected in the Senior VO2max value of 63.8 ± 4.8 ml·kg(-1)·min(-1). Senior lead hand straight punching force (head 1722 ± 700 N and body 1682 ± 636 N) was lower than the straight rear hand (head 2643 ± 1273 N and body 2646 ± 1083 N), lead hook (head 2412 ± 813 N and body 2414 ± 718 N) and rear hook (head 2588 ± 1040 N and body 2555 ± 926 N). It was concluded that amateur boxing performance is dependent on the interplay between anaerobic and aerobic energy systems. Current weight making methods may lead to impaired substrate availability, leading to reduced competitive performance and an increased risk to a boxers health. Key PointsSenior England international amateur boxers decrease 6.0-8.3 % (7.0 ± 0.8 %) body weight over a 21-day pre-contest period by employing passive and active weight making methods.Urine osmolality values >1000 mOsm·kg(-1) are recorded during training and competition.Senior and Junior England international amateur boxers experience high post contest blood lactate values (Seniors 13.5 ± 2 mmol·l(-1) and Juniors 14.1 ± 2 mmol·l(-1) under the current 4 rounds x 2-minute contest format.Senior England international amateur boxers have a high relative VO2max of 63.8 ± 4.8 ml·kg(-1)·min(-1)Senior England international amateur boxers have a straight and hook punch force >2400 N, except for the straight lead hand to the head and body.Journal of sports science & medicine 01/2006; 5(CSSI):74-89. · 0.90 Impact Factor
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ABSTRACT: Weight-class sports incite the sportsmen to loose weight to change class and increase their chance of success in competition. Although these sports are very demanding on the physiological level (high intensity), most of the competitors undertake caloric restrictions that are likely to induce physiological disorders detrimental to their health and sport performances. Two strategies allow to loose bodyweight. The first is maintained over a very short time (less than 1 week), the second is maintained over a longer period (several weeks). Managing weight reduction, food intake, and physical activities over several weeks is a particularly efficient way to conserve the sportsman’s performance abilities. On the other hand, the transgression of certain principles in only one of these fields is enough to deteriorate the sportsman's capacities of performance and (or) his health, whatever the duration of the period of the loss of weight. During food restriction, the carbohydrate and protein rations must be increased to prevent the unavoidable involutions of body composition and performance. In spite of food restriction, the training intensity must be high, and only the training volume must decrease to remain competitive.Applied Physiology Nutrition and Metabolism 12/2006; 31(6):684-692. · 2.01 Impact Factor