Hydration and Performance in Young Triathletes During a Competition in Tropical Climate.

PURPOSE: We examined fluid intake, the relation between body mass (BM) loss and performance, and core temperature in young triathletes during a competition in tropical climate. METHODS: Fluid intake and pre and post BM were measured in 35 adolescent athletes, and core temperature was measured in one female and one male. RESULTS: Mean urine specific gravity (1.024 [0.007]) indicated that athletes were in suboptimal state of hydration upon waking. Race time was 73.2 (8.0) minutes. BM decreased by 0.6 (0.3) kg (P < .05). Fluid intake (528.5 [221.6] mL) replaced 47% of the fluid loss (1184.9 [256.4] mL) and was higher during run (11.5 [6.6] mL·min-1) compared to bike (7.3 [3.1] mL·min-1), P < .01. Loss in BM was ≥1.0% in 66% and ≥1.5% in 29% of the athletes. Males showed a moderate association between percentage loss in BM and finishing time (r = -.52), higher sweat rates (1.0 [0.3] L·h-1), and faster times (69.4 [7.5] min; P < .05). Core temperature rose to 40.1 °C in the female and 39.6 °C in the male. CONCLUSION: Young triathletes competing in a hot/humid climate became mildly to moderately dehydrated and hyperthermic even when water and sports drinks were available but did not show symptoms of heat illness.

Return-to-Competition Progression After Exertional Heat Stroke in an Adolescent Runner: A Case Report.

A 14-year-old runner indigenous to the tropics collapsed during his first 10-km race in a hot and humid climate. Dizziness, stumbling, and loss of consciousness were symptoms of exertional heat stroke. Two days postcollapse, blood tests revealed elevated hepatic transaminases consistent with hepatic injury. We discuss the return-to-competition progression, which included a gradual increase in exercise duration, initially in a cool and then in a tropical climate, and 2 field-based (wet-bulb globe temperature > 29.0°C) running evaluations that simulated the environmental conditions and training intensity the athlete would encounter in his sport. The thermoregulatory results guided the training progression, his tolerance to running in the heat improved, blood values normalized, and he was cleared to compete in a tropical climate. This exploration case report presents a novel field-based protocol that replicates the physiological demands of training in the tropics to evaluate thermoregulatory responses during exercise-heat stress in young runners after exertional heat stroke to facilitate a safe return to competition.

Evidence for isokinetic and functional testing in return to sport decisions following ACL surgery.

The rupture and reconstruction of the anterior cruciate ligament (ACL) of the knee are associated with an increased risk of functional instability, a reduction in sports performance, and a higher risk of future additional injuries. Competitive athletes who participate in sports that require pivoting, cutting, and jumping are at particularly high risk for ACL rupture. The return to sport progression continuum after surgery includes sports-specific rehabilitation, evaluation of strength and function, gradual participation in exercise training with progressively challenging activities in the field of play, participation in sports at a lower level, and finally a return to preinjury-level sports competition. This narrative review evaluates the evidence that supports the use of quadriceps and hamstrings isokinetic strength testing and sports-specific functional skills assessments to evaluate progress with rehabilitation after ACL surgery. Strength evaluations, hop tests, agility tests, and the limb symmetry index are described, as well as the associations of quadriceps and hamstrings muscle strength and functional test results with successful return to sports and the risk of ACL graft rupture and contralateral knee injuries. Suggestions for future research directions are presented including the importance of presurgery testing, standardization of test batteries, and comparison of test results with normative data.

Normative Data for Sweat Rate and Whole-Body Sodium Concentration in Athletes Indigenous to Tropical Climate.

This study determined normative data for sweat rate (SR) and whole-body (WB) sweat sodium concentration [Na+] in athletes indigenous to a tropical climate, categorized by age, gender, and sport classification. We analyzed data from 556 athletes (386 adult and 170 young) in endurance (END), team/ball (TBA), and combat (COM) sports exercising in tropical environments (wet bulb globe temperature = 29.4 ± 2.1 °C). SR was calculated from change in body weight corrected for urine output and fluid/food intake. Sweat was collected using absorbent patches, and regional [Na+] was determined using an ion selective analyzer and normalized to WB sweat [Na+]. Data are expressed as mean ± SD. SR was higher in males compared with females in both young (24.2 ± 7.7 ml·kg-1·hr-1 vs. 16.7 ± 5.7 ml·kg-1·hr-1) and adult (22.8 ± 7.4 ml·kg-1·hr-1 vs. 18.6 ± 7.0 ml·kg-1·hr-1) athletes, in END sports in girls (END = 19.1 ± 6.0 ml·kg-1·hr-1; TBA = 14.6 ± 4.5 ml·kg-1·hr-1), and in adult males (END = 25.2 ± 6.3 ml·kg-1·hr-1; TBA = 19.1 ± 7.2 ml·kg-1·hr-1; COM = 18.4 ± 8.5 ml·kg-1·hr-1) and females (END = 23.5 ± 5.6 ml·kg-1·hr-1; TBA = 14.2 ± 5.2 ml·kg-1·hr-1; COM = 15.3 ± 5.2 ml·kg-1·hr-1); p < .05. WB sweat [Na+] was higher in adult athletes than in young athletes (43 ± 10 mmol/L vs. 40 ± 9 mmol/L, p < .05). These norms provide a reference range for low, low average, average high, and high SR and WB sweat [Na+], which serve as a guide for fluid replacement for athletes who live and train in the tropics.

Sweating and core temperature in athletes training in continuous and intermittent sports in tropical climate / Sudoración y temperatura interna en atletas durante entrenamiento para deportes continuos e intermitentes en clima tropical

Higher sweat rate values have been reported during intermittent compared to continuous type exercise in hot conditions in the laboratory. Studies in the training field are scarce. Objective: Document sweat rate, rehydration and core temperature (Tc) during training in long duration-continuous (CON) and intermittent (INT ) type sports, and determine the presence of a mutation in the CFTR gene in athletes with high sodium concentration ([Na+]) in sweat.Methods: Athletes (CON =50 and INT=123) were tested during training in tropical climate. Sweat rate, sweat [Na+], Tc, de-hydration level, and presence of ∆ F508 gene mutation in the CFTR gene in athletes with high sweat [Na+] were evaluated. Results: Sweat rate was higher in CON (1.5 ± 0.4 L/h) compared to INT (1.2 ± 0.5 L/h) and CON athletes finished training with higher dehydration (2.1 ± 0.8 vs 1.2 ± 0.7%) P < 0.05. Sweat [Na+] was higher in INT (62.0 ± 21.1 mmol/L) compared to CON (53.9 ± 18.1 mmol/L), P < 0.05. A tennis player with high [Na+] was heterozygous for the ΔF508 mutation. Average and highest Tc was similar for CON (38.4 ± 0.3 and 38.8 ± 0.4 oC) and INT (38.3 ± 0.3 and 38.7 ± 0.4 oC), P > 0.05. Conclusion: During training in a tropical climate, sweat loss and dehydration level are lower, and fluid intake is higher in intermittent compared to continuous type sports. Core temperature may rise to a similar level in intermittent type sports due to the repeated high intensity bouts and/or the effects of clothing worn while training in hot venues. Healthy athletes with high [Na+] in sweat who are heterozygous carriers of CFTR mutations may be at increased risk for hyponatremic dehydration and whole-body muscle cramps

Se reportan tasas de sudoración más altas durante ejercicio intermitente comparado con continuo en condiciones de calor en el laboratorio. Estudios en el campo de entrenamiento son escasos. Objetivo: Documentar la tasa de sudoración, rehidratación y temperatura central (Tc) durante entrenamiento para deportes de tipo continuo (CON) e intermitente (INT ), y determinar presencia de mutación genética en el gen CFTR en atletas con alta concentración de sodio ([Na+]) en sudor.Metodología: Se evaluó la tasa de sudoración, la [Na+] en sudor, la Tc, y el nivel de deshidratación en atletas (CON = 50; INT =123) durante entrenamiento en clima tropical, y la presencia de la mutación genética ∆F508 en el gen CFTR en aquellos con alta [Na+] en sudor.Resultados: La tasa de sudoración fue mayor en CON (1,5 ± 0,4 L/h) comparado con INT (1,2 ± 0,5 L/h) y los atletas en CON terminaron el entrenamiento con mayor deshidratación (2,1 ± 0,8 vs 1,2 ± 0,7%) P < 0,05. La [Na+] en sudor fue más alta en INT (62,0 ± 21,1 mmol/L) comparado con CON (53,9 ± 18,1 mmol/L), P < 0,05. Un tenista con alta [Na+] era heterocigoto para la mutación ΔF508. La Tc promedio y más alta fueron similares para CON (38,4 ± 0,3 y 38,8 ± 0,4 oC) e INT (38,3 ± 0,3 y 38,7 ± 0,4 oC), P > 0,05. Conclusión: Durante el entrenamiento en clima tropical, la pérdida de sudor y el nivel de deshidratación son más bajos, y la ingesta de líquido es más alta en deportes intermitentes que en deportes continuos. La temperatura interna puede aumentar a nivel similar en deportes intermitentes debido a periodos repetidos de alta intensidad y/o la vestimenta usada durante el entrenamiento. Atletas saludables con alta [Na+] en sudor que son heterocigóticos para mutaciones de CFTR pueden estar en mayor riesgo de deshidratación hiponatrémica y calambres musculares

Principles of exercise physiology: responses to acute exercise and long-term adaptations to training.

Physical activity and fitness are associated with a lower prevalence of chronic diseases, such as heart disease, cancer, high blood pressure, and diabetes. This review discusses the body's response to an acute bout of exercise and long-term physiological adaptations to exercise training with an emphasis on endurance exercise. An overview is provided of skeletal muscle actions, muscle fiber types, and the major metabolic pathways involved in energy production. The importance of adequate fluid intake during exercise sessions to prevent impairments induced by dehydration on endurance exercise, muscular power, and strength is discussed. Physiological adaptations that result from regular exercise training such as increases in cardiorespiratory capacity and strength are mentioned. The review emphasizes the cardiovascular and metabolic adaptations that lead to improvements in maximal oxygen capacity.

Hydration status in adolescent judo athletes before and after training in the heat.

UNLABELLED: Adolescent judo athletes who train in tropical climates may be in a persistent state of dehydration because they frequently restrict fluids during daily training sessions to maintain or reduce their body weight and are not given enough opportunities to drink. PURPOSE: Determine the body hydration status of adolescent judo athletes before, immediately after, and 24 h after (24H) a training session and document sweat Na+ loss and symptoms of dehydration. METHODS: Body mass and urine color and specific gravity (USG) were measured before, after, and 24 h after a training session in a high-heat-stress environment (29.5 ± 1.0°C; 77.7 ± 6.1% RH) in 24 adolescent athletes. Sweat sodium loss was also determined. A comparison was made between mid-pubertal (MP) and late pubertal (LP) subjects. RESULTS: The majority of the subjects started training with a significant level of dehydration. During the training session, MP subjects lost 1.3 ± 0.8% of their pretraining body mass whereas LP subjects lost 1.9 ± 0.5% (P < .05). Sweat sodium concentration was 44.5 ± 23.3 mmol/L. Fluid intake from a water fountain was minimal. Subjects reported symptoms of dehydration during the session, which in some cases persisted throughout the night and the next day. The 24H USG was 1.028 ± 0.004 and 1.027 ± 0.005 g/mL for MP and LP, respectively. CONCLUSIONS: Adolescent judo athletes arrive to practice with a fluid deficit, do not drink enough during training, and experience symptoms of dehydration, which may compromise the quality of training and general well-being.

Self-reported physical activity in Hispanic adults living with HIV: comparison with accelerometer and pedometer.

Limited information is available regarding physical activity (PA) and its assessment in Hispanics living with HIV. This study compared self-reported PA using the International Physical Activity Questionnaire (IPAQ) with objectively measured PA using the ActiGraph accelerometer and DigiWalker pedometer in 58 Hispanic adults with HIV. IPAQ was administered before and after a 7-day period in which subjects wore the ActiGraph and DigiWalker. PA classification was based on > or = 150 min/wk (IPAQ, ActiGraph) and > or = 10,000 steps/day (DigiWalker). IPAQ-PA was higher than ActiGraph-PA (423 +/- 298 vs. 165 +/- 134 min/wk, respectively) (p < .01). There was a mismatch in PA classification with the IPAQ, ActiGraph, and DigiWalker (active = 81%, 54%, and 17%, respectively). Hispanics with HIV highly overestimated self-reported PA. Nurse scientists and other investigators must consider accelerometers or pedometers to assess PA in this population.

Voluntary drinking and hydration in trained, heat-acclimatized girls exercising in a hot and humid climate.

This study examined the effects of beverage composition on the voluntary drinking pattern, body fluid balance and body temperature responses of heat-acclimatized trained girls exercising intermittently in outdoor conditions (WBGT = 30.9 +/- 0.2 degrees C). Twelve trained, heat-acclimatized girls (age = 10.6 +/- 0.2 years) performed three 3-h sessions, each consisting of four 20-min cycling bouts at 60% VO2max, alternating with 25-min rest. One of three beverages was assigned: unflavored water (W), flavored water (FW) or flavored water plus 6% carbohydrate and 18 mmol/l NaCl (CNa). Drinking was ad libitum. Total intake was similar among conditions (W = 953.3 +/- 107.8 ; FW = 1026.5 +/- 138.1; CNa = 906.4 +/- 107.5 g). A mild hypohydration occurred during the three conditions (W = -1.12%; FW = -0.95%; CNa = -0.74% BW, P > 0.05). Sweat loss, higher than previously reported for sedentary girls, was not different among conditions (W = 1,051.5 +/- 90.8; FW = 979.9 +/- 72.8; CNa = 1,052.7 +/- 52.6 g). The average amount of urine produced (W = 269.8 +/- 85.9; FW = 320.8 +/- 87.2; CNa = 85.6 +/- 9.3 g) was 73 and 68% lower [corrected] during CNa compared to [corrected] FW and W, respectively, [corrected] (CNa vs. FW, P < 0.05), CNa vs W, P = 0.06) [corrected] The increase in rectal temperature, heart rate and all perceptual variables did not differ among conditions. In conclusion, flavoring of the water and addition of 6% carbohydrate plus 18 mmol/l NaCl do not prevent mild hypohydration in trained, heat-acclimatized girls with high sweating rates. However, there is a tendency towards a greater fluid retention with the CNa beverage.

Voluntary drinking and hydration in non-acclimatized girls exercising in the heat.

The intent of this study was to assess the influence of drink flavor and composition on voluntary drinking and hydration status in girls exercising intermittently in the heat (35 +/- 1 degrees C, 45-50% relative humidity). Twelve physically active, nonacclimatized girls (9-12 years) performed three 3 h identical sessions, each consisting of four 20 min cycling bouts at 50% (VO(2max)), separated by 25 min of rest. One of the three beverages (chilled to 8-10 degrees C) was assigned to each session: unflavored water (W), grape-flavored water (FW) and grape-flavored water plus 6% carbohydrate and 18 mmol l(-1) NaCl (CNa). Drinking was ad libitum. Body weight (BW), drink intake (DI), heart rate, rectal and skin temperatures, and perceptions of thirst and stomach fullness were monitored periodically. Total DI was 759, 940, 1,045 g in W, FW and CNa, respectively (P < 0.05 for CNa-W and FW-W). BW changes were -0.15, 0.16, and 0.45% in W, FW and CNa, respectively, but only the difference between CNa and W was significant (P < 0.05). Other physiological and perceptual variables were not different between trials. In conclusion, beverage flavoring regardless if its combination with carbohydrate and NaCl, mildly enhanced voluntary drinking in young non-acclimatized girls. In contrast to previous research in young boys, euhydration was maintained in the girls by an adequate intake of unflavored water.

Effect of drink pattern and solar radiation on thermoregulation and fluid balance during exercise in chronically heat acclimatized children.

The purposes of this study were to examine the thermoregulatory and body fluid balance responses in chronically heat acclimatized children, i.e., indigenous to a tropical climate, during exercise in four outdoor conditions and the effects of dehydration on their thermoregulatory response. Nine children (age = 13.3 ± 1.9 yr, VO2 max = 45.5 ± 9.2 ml · kg-1 · min-1 ) cycled at 60% VO2 max each under four conditions: sun exposure voluntary drinking (SuVD), sun exposure forced drinking (SuFD), shaded voluntary drinking (ShVD), and shaded forced drinking (ShFD). Exercise sessions consisted of four 20-min exercise bouts alternating with 25-min rest periods. Globe temperature and the WBGT index were higher during SuVD and SuFD compared to ShVD and ShFD (P < 0.05). The change in rectal temperature, metabolic heat production, and heat storage did not differ among the conditions. Total water intake (% IBW) was higher during SuFD (4.1 ± 0.01) and ShFD (3.7 ± 0.1) compared to SuVD (2.1 ± 0.1) and ShVD (1.0 ± 0.1) and during SuVD compared to ShVD (P < 0.05). Sweating rate (L · hr-1 ) was higher during SuFD (0.7 ± 0.1) and ShFD (0.6 ± 0.1) compared to SuVD (0.5 ± 0.1) and ShVD (0.4 ± 0.1) (P < 0.05). Total fluid loss did not differ among conditions (SuVD = 1.7 ± 0.4; SuFD = 1.5 ± 0.4; ShVD = 2.1 ± 0.2; ShFD = 1.3 ± 0.3). Results indicate that when exercising in a tropical climate, chronically heat acclimatized children demonstrate mild voluntary dehydration and adequate heat dissipation. © 1995 Wiley-Liss, Inc.

Perfil antropométrico y fisiológico de atletas puertorriqueños: softbol femenino / Anthropometric and physiologic profile of Puerto Rican athletes: female softball

This study was conducted to describe and compare various anthropometric, body composition, cardiorespiratory, metabolic and neuromuscular characteristics of 12 female athletes, members of the Puerto Rico national softball team. The subjects were divided into three categories according to their game specific requirements (game position): infielders (n = 5), outfielders (n = 4), and pitchers (n = 3). The mean and standard deviations of all the variables in each group was calculated. These athletes demonstrated high levels of body fat and below optimal levels of flexibility, cardiorespiratory endurance, and muscular strength and endurance. The results revealed deficiencies in the health related fitness components and in the physical preparation for sports competition. These results also suggest that the subjects are at risk for the development of cardiovascular diseases, sport injuries, and poor sport performance

Morbilidad durante los XVI Juegos Deportivos Centroamericanos y del Caribe: Delegación de Puerto Rico, México 1990 / Morbidity during the XVI Central American and Caribbean Games: Puerto Rico delegation, Mexico 1990

The health services offered to the Puerto Rican Delegation during the XVI Central American and Caribbean Sports Games in México in 1990 included: medical, dental and psychological assistance, physical therapy and services on the playing field. From the consultation sheets completed during the Games we obtained information about the use of these services. The 336 members of the Puerto Rico Delegation in the village at México City had 1,838 encounters with the health team. Of these, 991 were medical consults, 55 group therapies, 466 physical therapy sessions and 326 encounters in the sports venues. Among the encounters for medical evaluation the most frequent problems were athletic injuries (318; 32.1 percent), respiratory problems (240; 24.2 percent), gastrointestinal conditions (126; 12.7 percent) and dental services (119; 12.0 percent). The most frequent athletic injuries were first degree strains (83; 26.1 percent), tendinitis (56; 17.6 percent), contusions (42; 13.2 percent), myositis (40; 12.6 percent) and first degree sprains (28; 8.8 percent). The health problems found were diversed and in the majority of cases mild in character, which can be attend by adequately trained on sports health primary health professionals

Fisiologia de la mujer durante el ejercicio / Female physiology during exercise

Las repuestas fisiológicas y adaptaciones de la mujer al ejercicio dependen de sus características morfológicas y funcionales, determinadas genéticamente, y de su nivel de acondicionamiento físico. La mujer demuestra respuestas funcionales cuantitativamente diferentes a las del hombre durante elejercicio submáximo y máximo pero exhibe adaptaciones al entrenamiento cualitativamente similares. Gran parte de la diferencia en a ejecutoria atlética entre la mujer y el hombre en eventos que requieren una lata potencia aeróbica o anaeróbica se debe a diferencias en estructura y composición corporal: la mujer promedio es de menor estatura y peso, y posee menos masa mucular. Esta características influyen en la respuesta fisiológica de los sistemas musculo-esqueletal, cardiovascular, y respiratório durante el ejercicio. En este artículo se describen las respuestas fisiológicas de la mujer durante el ejercicio, la relación de estas respuestas con las características morfológicas y las diferencias del sexo masculino. Además, se discuten las adaptaciones que ocurren con el entrenamiento físico