Blood Chemical Analysis ; Humans ; Water Sports ; physiology

Scuba diving is a popular sports activity, even though it is associated with potential hazards. When a diver enters the water for an underwater expedition, he/she needs a series of diving gear, including a regulator, buoyancy compensator, diving suit, and weight belt, among others. Here, the author encountered a fatal diving accident wherein autopsy showed the evidence of death by drowning. The witness stated that the diver requested more weight to descend into the water, and the diver wore one more weight belt, totalling 26 kg. After a second trial of diving, he did not grab the regulator and disappeared into the water suddenly, and bubbles did not appear at the surface. Based on the witness statement and autopsy findings, the original cause of accident was concluded as an overweighted belt for descent into the water.
Autopsy ; Diving ; Drowning ; Expeditions ; Overweight ; Sports ; Water

Catecholamines ; blood ; Heart Rate ; Humans ; Water Sports ; physiology

A good hydration status is important to the exercise performance and cognitive function of exercisers.The effective restoration of fluid balance after exercise is helpful to prevent dehydration,maintain body fluid balance,accelerate fatigue recovery,and enhance exercise performance.As the most effective sports nutrition supplement,sports beverage has different ingredients and formulas,and also has various effects.To provide clues for the development of sports beverage,this article reviews the types,components,effects,and mechanisms of sports beverage currently used in post-exercise fluid restoration.
Beverages ; Dehydration ; Exercise ; Fluid Therapy ; Humans ; Sports ; Water-Electrolyte Balance

BACKGROUND/OBJECTIVES: The purpose of this study was to assess the accuracy of a dietary reference intake (DRI) predictive equation for estimated energy requirements (EER) in female college tennis athletes and non-athlete students using doubly labeled water (DLW) as a reference method. MATERIALS/METHODS: Fifteen female college students, including eight tennis athletes and seven non-athlete subjects (aged between 19 to 24 years), were involved in the study. Subjects' total energy expenditure (TEE) was measured by the DLW method, and EER were calculated using the DRI predictive equation. The accuracy of this equation was assessed by comparing the EER calculated using the DRI predictive equation (EER(DRI)) and TEE measured by the DLW method (TEE(DLW)) based on calculation of percentage difference mean and percentage of accurate prediction. The agreement between the two methods was assessed by the Bland-Altman method. RESULTS: The percentage difference mean between the methods was -1.1% in athletes and 1.8% in non-athlete subjects, whereas the percentage of accurate prediction was 37.5% and 85.7%, respectively. In the case of athletic subjects, the DRI predictive equation showed a clear bias negatively proportional to the subjects' TEE. CONCLUSIONS: The results from this study suggest that the DRI predictive equation could be used to obtain EER in non-athlete female college students at a group level. However, this equation would be difficult to use in the case of athletes at the group and individual levels. The development of a new and more appropriate equation for the prediction of energy expenditure in athletes is proposed.
Athletes* ; Bias (Epidemiology) ; Energy Metabolism ; Female* ; Humans ; Methods* ; Motor Activity ; Recommended Dietary Allowances* ; Sports ; Tennis* ; Water*

OBJECTIVE: To investigate the effects of intermittent negative pressure therapy on the skin microcirculation perfusion of quadriceps in male rowers, and to provide basis for the practical application of this method. METHODS: Fourteen male rowers were selected from the national rowing team and randomly divided into experimental and control groups. The daily training plans of two groups were the same. The recovery intervention for experimental group was implemented by 20 minutes in the cube of Vacusport Regeneration System (German), 5 times per week for 4 weeks, no recovery intervention for control group. Microcirculation markers were collected by PeriFlux5000 system before and after the 4-week intervention. The markers included microcirculatory blood perfusion(MBP), average velocity of blood cells(AVBC), concentration of moving blood cells (CMBC), and values of the markers included basic values and post-heating values (44℃), difference before and after heating of the values was considered as the reserve capacity of those markers. RESULTS: The test results before the 4 weeks intervention showed there was no statistical difference between the two groups(P＞0.05). After the 4 weeks intervention: ①MBP: The post-heating value and the difference of the experimental group were significantly higher than those of the control group (P＜0.05). But there was no statistical inner-group difference. ②AVBC: The post-heating values and the difference in the experimental group were significantly lower than those in the control group (P＜0.05). Intra-group comparison found that the post-heating values after post-intervention were significantly reduced, compared with those of pre-intervention (P＜ 0.01); the difference after post-intervention was reduced significantly, compared with those in the pre-intervention (P＜0.05). ③CMBC: The post-heating values and the difference in the experimental group were significantly higher than those in the control group (P＜0.01). There were no statistical significant inner-group difference. CONCLUSION Lower limb intermittent negative pressure therapy can improve the skin microcirculation of the quadriceps of the male rowers, which has a positive effect on the rapid recovery of physical fitness.
Humans ; Lower Extremity ; Male ; Microcirculation ; Pressure ; Quadriceps Muscle ; blood supply ; Skin ; blood supply ; Water Sports

OBJECTIVES: The aim of this investigation was to give insights into the impact of carbohydrate-electrolyte drinks on the likely capacity of enamel surface dissolution and the influence of human saliva exposure as a biological protective factor. MATERIALS AND METHODS: The pH, titratable acidity (TA) to pH 7.0, and buffer capacity (β) of common beverages ingested by patients under physical activity were analyzed. Then, we randomly distributed 50 specimens of human enamel into 5 groups. Processed and natural coconut water served as controls for testing three carbohydrate-electrolyte drinks. In all specimens, we measured surface microhardness (Knoop hardness numbers) and enamel loss (profilometry, µm) for baseline and after simulated intake cycling exposure model. We also prepared areas of specimens to be exposed to human saliva overnight prior to the simulated intake cycling exposure. The cycles were performed by alternated immersions in beverages and artificial saliva. ANOVA two-way and Tukey HDS tests were used. RESULTS: The range of pH, TA, and β were 2.85 - 4.81, 8.33 - 46.66 mM/L and 3.48 - 10.25 mM/L × pH, respectively. The highest capacity of enamel surface dissolution was found for commercially available sports drinks for all variables. Single time human saliva exposure failed to significantly promote protective effect for the acidic attack of beverages. CONCLUSIONS: In this study, carbohydrate-electrolyte drinks usually consumed during endurance training may have a greater capacity of dissolution of enamel surface depending on their physicochemical proprieties associated with pH and titratable acidity.
Beverages ; Cocos ; Dental Enamel* ; Hardness ; Humans* ; Hydrogen-Ion Concentration ; Immersion ; Motor Activity ; Protective Factors ; Saliva ; Saliva, Artificial ; Sports ; Water

We investigated the comparative effect of magnesium and thiosulfate on the calcium oxalate crystallization. Magnesium is a strong inhibitor of calcium oxalate crystallization and it is sported to inhibit calcium phophate by about 20%. Even if it's mechanism is not clearly known, thiosulfat can resolve 250~100,000 times more than other calcium salts when it is combined with calcium. Wistar rats were fed by 1.0% ethylene glycol (EG) mixed with water. 500mg of magnesium oxide (MgO) per 100gm chows and 10mMo1 of S2O3 per 100gm chows were provided by oral intake respectively. Forty eight wistar rats were divided into following 6 groups. Each group has equal 8 wistar rats; A group (normal chow and water), B group (normal chow and 1%EG), C group (MgO and 1%EG), D group (MgO and water), E group (S2O3 and 1%EG), and F group (S2O3 and water). First, we examined calcium oxalate crystallization on bladder aspiration urine for 6 groups before the experiment and every week for 4 weeks after the experiment. Second, we also examined the degree of formation of calcium oxalate crystallization in renal tissue under polarizing microscope. Calcium oxalate crystallization was found in all 8 wistar rats in B group while it was not round in A, D, F group. Calcium oxalate crystallization was also found in one out of 8 wistar rats in C group, and 5 out of 8 wistar rats in E group. In conclusion, we believe that both MgO and sodium thiosulfate are effective in preventing calcium oxalate stone, and we also believe MgO is more elective than sodium thiosulfate. We think that further researches on administrating methods, the side effects and dosage of these two agents in human are necessary.
Calcium Oxalate* ; Calcium* ; Crystallization* ; Ethylene Glycol ; Humans ; Magnesium Oxide* ; Magnesium* ; Nephrolithiasis ; Rats, Wistar ; Salts ; Sodium* ; Sports ; Urinary Bladder ; Water

The purpose of this study was to determine the effects of beverage temperature and composition on weight retention and fluid balance upon voluntary drinking following exercise induced-dehydration. Eight men who were not acclimated to heat participated in four randomly ordered testing sessions. In each session, the subjects ran on a treadmill in a chamber maintained at 37degrees C without being supplied fluids until 2% body weight reduction was reached. After termination of exercise, they recovered for 90 min under ambient air conditions and received one of the following four test beverages: 10degrees C water (10W), 10degrees C sports drink (10S), 26degrees C water (26W), and 26degrees C sports drink (26S). They consumed the beverages ad libitum. The volume of beverage consumed and body weight were measured at 30, 60, and 90 min post-recovery. Blood samples were taken before and immediately after exercise as well as at the end of recovery in order to measure plasma parameters and electrolyte concentrations. We found that mean body weight decreased by 1.8-2.0% following exercise. No differences in mean arterial pressure, plasma volume, plasma osmolality, and blood electrolytes were observed among the conditions. Total beverage volumes consumed were 1,164 +/- 388, 1,505 +/- 614, 948 +/- 297, and 1,239 +/- 401 ml for 10W, 10S, 26W, and 26S respectively (P > 0.05). Weight retention at the end of recovery from dehydration was highest in 10S (1.3 +/- 0.7 kg) compared to 10W (0.4 +/- 0.5 kg), 26W (0.4 +/- 0.4 kg), and (0.6 +/- 0.4 kg) (P < 0.005). Based on these results, carbohydrate/electrolyte-containing beverages at cool temperature were the most favorable for consumption and weight retention compared to plain water and moderate temperature beverages.
Arterial Pressure ; Beverages ; Body Weight ; Dehydration ; Drinking ; Electrolytes ; Fluid Therapy ; Hot Temperature ; Humans ; Male ; Osmolar Concentration ; Plasma ; Plasma Volume ; Retention (Psychology) ; Sports ; Water ; Water-Electrolyte Balance

BACKGROUND: There are approximately 2,400 drowning deaths reported every year in Korea, but there are few good reports about submerged patients visiting the emergency room, so this study was designed to investigate the clinical characteristics and outcomes of submerged patients treated at an emergency medical center near the Han river. METHODS: A retrospective review of 123 cases of submerged patients admitted to our emergency medical center over a 5 year period from 1996 to 2000 was conducted. RESULTS: Among the 123 submerged patients, there were 66 males and 57 females, and their mean age was 33.18. The common cause of submersions was a suicide attempt, followed by lack of attention, unknown etiology, and water sports such as swimming. Most of the patients were transported to ER by 119 ambulance. In-hospital CPR was performed on 27(22%) cases. At initial ECG rhythm of these cases, asystole was noted in 25 patients; VF and pulseless electrical activity, respectively, were noted in two others. Prehospital CPR had been performed on all in-hospital CPR cases except 2. Prolonged ROSC after succesful CPR was noted in 13 cases. The mean duration of CPR was 26 minutes. Five patients survived after CPR. Their neurologic outcomes were assessed on CPC(cerebral performance category). Three patients were categorized in CPC1, the other two patients were categorized in CPC3 and CPC4. CONCLUSION: Submerged patient's visits to emergency medical center near the Han river were most frequent in summer for suicide purposes. Drowned patients were more hypothermic than other cardiac arrest cases, and resulted in better outcome even with prolonged arrest time, if they were given appropriate prehospital CPR and aggressive in-hospital resuscitation.
Ambulances ; Cardiopulmonary Resuscitation ; Drowning ; Electrocardiography ; Emergencies* ; Emergency Service, Hospital ; Female ; Heart Arrest ; Humans ; Immersion ; Korea ; Male ; Resuscitation ; Retrospective Studies ; Rivers* ; Sports ; Suicide ; Swimming ; Water