摘要:

EHN, LARS, BJÖRN CARLMARK, and SVERKER HÖGLUND. Iron status in athletes involved in intense physical activity.Med. Sci. Sports Exercise. Vol. 12, No. 1, pp. 61–64, 1980. Iron status was studied in 8 long distance runners. Training programs, diets, and general health were also investigated over a period of at least 2 years. Hemoglobin and serum iron did not differ from normals whereas bone marrow showed either an absence or only traces of iron indicating latent iron deficiency. Radio iron studies of heme and non-heme iron absorption and incorporation showed rather low values. However, they did not differ significantly from normal values. Whole body counting studies during 10 months showed increased elimination of radio iron corresponding to 2 mg iron/day. Due to a high daily iron intake, a balance was present. No signs of bleeding, hemolysis, or increased excretion of hemoglobin via the urine could be found. The low absorption and increased elimination of iron seems to be the explanation for the empty iron stores.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

CHANDLER, JOE V. and STEVEN N. BLAIR. The effect of amphetamines on selected physiological components related to athletic success.Med. Sci. Sports Exercise, Vol. 12, No. 1, pp. 65–69, 1980. Six male college students were tested under two experimental conditions; amphetamine and no amphetamine. Each subject was tested three times under each condition. A double-blind placebo-controlled approach was employed and on six consecutive Fridays the subjects received either a placebo or 15 mg of Dexedrine per 70 kg of body weight 2 hours prior to testing. The physiological components tested were strength, muscular power, running speed, acceleration, aerobic power, and anaerobic capacity. Other variables evaluated were pre-exercise and maximum heart rates, respiratory exchange ratio and time to exhaustion. Data analysis revealed significant increases in knee extension strength, acceleration, anaerobic capacity, time to exhaustion, and pre-exercise and maximum heart rates. The most revealing results were in the area of increased time to exhaustion during the Vo2max test presumably due to higher lactic acid tolerance, thus a possible rationale to substantiate the theory that this drug has the ability to mask fatigue. It may also be possible that the biochemical actions of the drug alter fatigue processes directly. The results demonstrate that amphetamines have no effect on aerobic power, but further research will be necessary to clarify the drug's influence on muscular power-dominated movements.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

GBIMBY, G., E. GUSTAFSSON, L. PETERSON, and P. RENSTROM. Quadriceps function and training after knee ligament surgery.Med. Sci. Sports Exercise, Vol. 12, No. 1, pp. 70–75,1980. A follow-up study of 30 patients operated on for knee ligament injuries was performed with measurements of maximal isometric and isokinetic (angular velocity 30, 42, 120°/s) torque for knee extension and muscle biopsy from vastus lateralis. The maximal torque values of the operated side were reduced in spite of resumed physical activities and athletic training. Isokinetic training, weight training (10 RM), and self-training were compared. All training groups increased their muscle strength with the largest increase for the isokinctically trained group. Before training, the mean fiber areas were somewhat low, especially for type II fibers and there was a tendency for an increase after training. There was no significant change in ATP, CP, and contractile enzyme activities with training. With the isokinetic training principle, maximal torque can in contrast to weight training be achieved through the whole range of motion, which may explain its larger training effect.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID