Showing papers in "Medicine and Science in Sports and Exercise in 1975"

HEAT TOLERANCE OF EXERCISING LEAN AND OBESE PREPUBERTAL BOYS: 9: a.m

Abstract: Seven lean and five obese boys, aged 9-12 yr, exercised in four environments: 21.1, 26.7, 29.4, and 32.2 degrees C Teff. Subjects walked on a treadmill at 4.8 km/h, 5% grade for three 20-min exercise bouts separated by 5-min rest periods. Rectal temperature (Tre), skin temperature (Tsk), heart rate (HR), sweat rate, and oxygen uptake (VO2) were measured periodically throughout the session. Lean boys had lower Tre and HR than obese boys in each of the environments. Increases in Tre were significantly greater for the obese at 26.7 and 29.4 degrees C Teff. No significant differences in Tsk and sweat rate (g-m-2-h-1) were observed between lean and obese boys. Obese boys had significantly lower oxygen consumptions per kg but worked at a significantly higher percentage of VO2max than lean boys when performing submaximal work. Responses of the obese boys to exercise in the heat were similar to those of heavy prepubertal girls studied previously, except that the boys were more tolerant of exercise at 32.2 degrees C Teff than the girls. Lean boys had lower HR than lean girls in each environment, but lower Tre only at 32.2 degrees C Teff.

ISOKINETIC VS. ISOTONIC STRENGTH TRAINING IN ADULT MEN: 11: a.m

Abstract: The differences in changes in strength, body composition, anthropometric measurements and selected motor performance tasks, between groups, trained isotonically and isokinetically were compared. Thirty-six male volunteers were randomly assigned to one of four groups: isotonic; isokinetic low speed contraction; isokinetic high speed contraction; and control. Strength training was conducted three days per week, 40 minutes per day for eight weeks. The results demonstrated a clear superiority of the isokinetic training procedures over the isotonic procedures relative to strength, antrhopometric measures and motor performance tasks. The three training groups exhibited similar changes in body composition. The isokinetic high speed group demonstrated the greatest gains overall. The significance of these results is discussed.

The gamma mass scanning technique for inertial anthropometric measurement.

Abstract: The validity of the gamma mass scanner in predicting center of mass and moment of inertia of biological tissue was tested using legs of lamb. The reaction board, immersion and pendulum methods were used to obtain one or both the center of mass and moment of inertia of the legs. The results from these methods were compared with those obtained from the scanner. Results indicated that the gamma mass scanner consistently predicted the mass of the legs to within a 1% error, the center of gravity within 2.1% and moment of inertia to within 4.8%. Within the limits of this investigation it was concluded that the gamma mass scanner shows promise as a valid and exact method for determining the center of gravity and moment of inertia of biological tissue.

THE BODY COMPOSITION OF A COLLEGE FOOTBALL TEAM: 10: a.m

Abstract: The body composition and anthropometric measurements of 65 college football players were studied. Body composition was determined by underwater weighing with an accurate assessment of residual volume. The anthropometric measurements included height, weight, seven skinfolds, waist circumference and wrist diameter. A step-wise multiple regression analysis of the data indicated that body density and body fat could be predicted from anthropometric measurements. A multiple correlation of .96 was found between body density and three independent variables (waist circumference, triceps skinfold and height). The derived regression equations' standard errors of the estimate were 0.0041 body density units and 1.64 percent fat respectively. The team data were divided into five categories by position. When subjected to analysis of variance, significant differences at the .01 level of confidence suggested that at least two separate groups, backs and linemen, be used in future body composition studies of football teams. The estimated optimal playing weights of each player were determined by densitometry, and each player and the coach estimated that their optimal weights through personal experience. It was found that the players and the coach estimated the players optimal mean weight by 9 and 6 pounds heavier, respectively, than the densitometric analysis indicated as optimal.

Adapted physical education

Abstract: nize the signs and symptoms of diabetic emergency and how to treat diabetic individuals in an emergency situation. • Treat students with diabetes the same as other students, except to meet medical needs. • Make sure substitute P.E. instructors are aware of student needs without violating the student’s right to privacy. • Create a Quick Reference Emergency Plan (QREP) in case the student goes into diabetic shock. The student, his/her parent(s), the school nurse, and the physical education teacher should create the QREP. The plan should include: • Names and numbers of important contacts • Causes, signs, and symptoms of hypoglycemia • Locations (gym, playing fields, off-campus facilities) for all units of instruction to ensure quick responses from emergency medical personnel • Actions needed or instructions for response to hypoglycemia • Include instructions for an emergency glucagon kit, if applicable • Carry personal supplies and keep readily available: • Blood glucose monitoring equipment • Emergency glucagon kit, if prescribed • Sugar in the form of juice, candy, or glucose tablets

OXYGEN UPTAKE FOR NEGATIVE WORK, STRETCHING, CONTRACTIONS BY IN SITU DOG SKELETAL MUSCLE: 10: a.m

Abstract: Oxygen uptake for negative work, stretching twitch contractions by in situ gastrocnemius-plantaris muscle was calculated from measurements of venous outflow and arterial and venous blood oxygen contents. Contractions were produced by valving air at high pressure into the pneumatic lever 10-50 ms before stimulation of the muscle. The loads produced were up to about 2.5 times isometric. Muscle length was always below optimal isometric length. Oxygen uptake for shortening contractions increased with increasing load up to isometric load. Oxygen uptake for stretching contractions decreased with increasing loads above isometric load. Velocity of shortening decreased with increasing loads up to isometric load whereas velocity of stretching increased with increasing loads above isometric. In shortening contractions external work done by the muscle was greatest at intermediate loads, but in stretching contractions the work done on the muscle increased with increasing loads. In stretching contractions the ratio of the energy equivalent of the work absorbed by the muscle reached 8.0 times the energy equivalent of the oxygen uptake. Since this ratio cannot exceed 1.0 for an engine, muscles must act as brakes during stretching contractions.

PREDICTION OF BODY COMPOSITION IN HABITUALLY ACTIVE MIDDLE-AGED MEN: 9: a.m

Abstract: In 45 physically active men (ages 35-67 yr) who underwent hydrostatic weighing to determine body composition, multiple regression equations were developed for the prediction of body density (D), lean body weight (LBW), fat body weight (FBW), and % fat using selected anthropometric measurements. The prediction accuracy for these parameters using several previously generated anthropometric regression equations was also determined. With equations developed from the present data a substantially higher correlation was obtained between measured and predicted LBW (r = 0.95) than between measured and predicted D (r = 0.85), FBW (r = 0.88), or % fat (r = 0.84). When previously developed equations were applied to the present sample, correlations between measured and predicted values were considerably lower (4-42%) than in the original studies; this reduction was least in the case of LBW. Analysis of previous data indicated that in selected populations total body weight can account for a relatively large fraction of the variance in LBW. LBW may be estimated quite accurately (r greater than or equal to 0.90) in physically active men with one of several regression equations which include total body weight as an independent variable.