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1.
J Strength Cond Res ; 38(4): 704-708, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38090979

RESUMEN

ABSTRACT: Howard, M, Sanders, GJ, Kollock, RO, Peacock, CA, and Freire, R. The effect of daily heart rate workloads on preseason, midseason, and postseason oxygen consumption in Division I basketball. J Strength Cond Res 38(4): 704-708, 2024-Basketball is a dynamic sport, requiring athletes to elicit a high-level of physical, tactical, technical, and psychological attributes and athletes must possess a robustly trained aerobic energy system. There is no research to assess how objectively measured training loads throughout a season influence aerobic capacity. The following study was a retrospective analysis of an NCAA Division I women's basketball team throughout a 5-month (23-week) competitive season. Data were sorted into season half totals and maximal oxygen consumption was recorded before, at the midway point and within 1-week postseason. Twelve athletes were monitored during each practice, pregame shoot around, scrimmage, and game for a total of 1,378 recorded sessions with a valid heart rate-based wearable microsensor (Polar Team Pro) during the season. There was a main effect of time for V̇O 2max throughout the season ( p < 0.001). Post hoc analysis revealed there was a significant increase in V̇O 2max from preseason to postseason ( p < 0.001). Interestingly, there were significant ( p ≤ 0.001 for all) decreases from the first half to the second half of the season for training load, and time allocated to HR Zone1-4 , but no difference in time for the most intense zone, HR zone5 . Conclusion: Oxygen consumption significantly increased 7.5% from preseason to postseason despite a reduction in overall work. The only training intensity that was not different from the first half to second half of the season was time in the highest heart rate intensity zone ≥85% of HR max .


Asunto(s)
Baloncesto , Humanos , Femenino , Baloncesto/fisiología , Carga de Trabajo , Frecuencia Cardíaca/fisiología , Estudios Retrospectivos , Consumo de Oxígeno/fisiología , Atletas
2.
J Int Soc Sports Nutr ; 20(1): 2247384, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37621001

RESUMEN

BACKGROUND: It is common practice for fight sport athletes to use a variety of weight manipulation strategies to compete in desired weight classes. Although numerous studies have highlighted rapid weight loss (RWL) strategies and the magnitude of weight loss, few have focused specifically on weight loss in female fighters. The purpose of this study was to provide descriptive information on professional UFC female fighters engaging in RWL in all women's UFC weight divisions: strawweight (52.2 kg): flyweight (56.7 kg); bantamweight (61.2 kg); featherweight (65.8 kg). METHODS: All fighter's weights were obtained at five separate time points: 72 hrs. pre-weigh-in, 48 hrs. pre-weigh-in, 24hrs. pre-weigh-in, official weigh-in, and 24 hrs. post-weigh-in (competition weight). Mixed effects models and random effects analysis were used to assess changes in weight and differences between weight divisions. All statistics were analyzed, and significance was set at p ≤0.05. Significant changes in weight between all time points were reported. RESULTS: No statistical differences between weight divisions were observed. Female fighters lost 4.5-6.6% of their weight prior to the official weigh-in. CONCLUSION: Females engaged in RWL practices lose weight in a similar fashion irrespective of weight class.


Asunto(s)
Atletas , Deportes , Humanos , Femenino , Pérdida de Peso
3.
J Funct Morphol Kinesiol ; 7(4)2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36547661

RESUMEN

Previous research has demonstrated that professional mixed martial arts (MMA) athletes employ a variety of weight manipulation strategies to compete at given weight classes. Although there is much literature demonstrating weight manipulation methods, minimal research exists analyzing how much weight MMA athletes lose prior to the official weigh-in. Moreover, there is minimal research examining how much weight professional MMA athletes gain between the official weigh-in and competition. Therefore, the purpose of the current study was to analyze weight loss/regain in professional MMA athletes. Data collected from 616 professional MMA athletes (31.1 ± 4.0 yrs.; 177.1 ± 4.7 cm) competing for the Ultimate Fighting Championship (UFC) between 2020 and 2022 were used for the study. The athlete's weight was obtained 72 h, 48 h, and 24 h prior to the official weigh-in, at the official weigh-in, and prior to competition. Random effects analysis was utilized to compare weight at a variety of time points between different weight classes. All statistics were analyzed, and significance was set at p ≤ 0.05. There is a significant (p ≤ 0.05) difference between weight classes and time points in professional MMA. MMA athletes decrease body weight significantly prior to the official weigh-in. MMA athletes increase body weight significantly between official weigh-in and competition. Based on these data, it appears that MMA athletes average a weight loss of nearly 7% within 72 h prior to the official weigh-in. The data also suggest that athletes gain nearly 10% of total weight between the official weigh-in and competition.

4.
J Strength Cond Res ; 36(1): 162-166, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31895280

RESUMEN

ABSTRACT: Sanders, GJ, Boos, B, Rhodes, J, Peacock, CA, Kollock, RO, and Scheadler, CM. Variability of competition-based caloric expenditure and relative heart rates in National Collegiate Athletic Association Division I women's basketball. J Strength Cond Res 36(1): 162-166, 2022-Basketball athletes frequently engage in high intensities (≥85% HRpeak) throughout competition, and it is unknown how high-intensity play coincides with caloric expenditure and average and peak relative heart rates. The purpose of the study was to assess caloric expenditure throughout 31 games (4- to 10-minute quarters) in National Collegiate Athletic Association Division I women's basketball. A total of 11 female athletes were tested for peak heart rate (HRpeak) and peak oxygen uptake (V̇o2peak) before the season, then monitored in-season with heart rate-based wearable devices. Estimated caloric expenditure, average (% HRavg) and peak (% HRpeak) relative heart rates, time played at intensities ≥85% HRpeak, and live time (i.e., game minutes not including stoppages in play) were recorded each game. Data were assessed as a team and compared across 4 quarters, and then, interathlete comparisons were made based on full game data. There were significant main effects of 10-minute quarters on calories (p < 0.001) and % HRavg (p = 0.015) but not playing intensity ≥85% HRpeak (p = 0.125) and % HRpeak (p = 0.629). Caloric expenditure was the only variable to increase from the first to the fourth quarter. There were main effects of individual athletes on calories, % HRavg, % HRpeak, live time, and playing intensity ≥85% HRpeak (p < 0.001 for all). Assessing individual athletes, relative to a team assessment across quarters, can provide practitioners with more accurate caloric expenditure, heart rate, and playing intensity data per athlete to improve training and fueling protocols.


Asunto(s)
Baloncesto , Atletas , Femenino , Gastos en Salud , Frecuencia Cardíaca , Humanos , Universidades
5.
Cureus ; 13(7): e16178, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34367785

RESUMEN

A large and growing body of research shows that non-caffeinated plant-based nutritional supplements can increase cognitive and physical performance. This study aimed to build on this work by investigating the possibility that a specific botanical blend (consisting of Bacopa monnieri bacosides, Kaempferia parviflora methoxy flavones, pomegranate peel polyphenols, and Moringa oleifera leaf saponins) could improve cognitive and physical performance. To this end, we carried out a randomized, double-blind, placebo-controlled 21-day parallel study on 36 healthy adults. We compared the effects of the botanical blend at baseline to a caffeine and a placebo condition on 1) self-reported alertness, anxiety, and headaches; 2) multiple measures of attention and cognition; 3) physical performance; and 4) stress biomarkers. We found that relative to baseline and compared to the Caffeine and Placebo groups, the botanical blend increased alertness and improved cognitive performance. The cognitive effects were most robust for attention measures. The botanical blend did not improve physical performance on a time to exhaustion (TTE) test. Of note, there was not the expected increase in catecholamine response after the TTE on Day 21, suggesting that long-term botanical blend use decreases the catecholamine stress response of a physical endurance task. In conclusion, we show that, within the confines of this study, a combination of the botanical blend could serve as a safe and effective nutritional supplement to improve cognitive performance.

6.
J Strength Cond Res ; 35(4): 1095-1102, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-30299392

RESUMEN

ABSTRACT: Sanders, GJ, Boos, B, Rhodes, J, Kollock, RO, and Peacock, CA. Competition-based heart rate, training load, and time played above 85% peak heart rate in NCAA division I women's basketball. J Strength Cond Res 35(4): 1095-1102, 2021-Basketball athletes frequently engage in intensities ≥85% HRpeak throughout competition. Knowing the time spent competing at intensities ≥85% HRpeak can improve training protocols. The purpose of the study was to assess heart rate responses across 4-quarter games (N = 31) in an NCAA Division I women's basketball season. Ten female athletes were tested and monitored with heart rate-based wearable microsensor devices. Before the season, HRpeak was recorded through a peak metabolic test (V̇o2peak). Average (HRavg) and HRpeak were recorded for each game, and time spent in 5 heart rate zones (HRZones) were recorded: HRZone1 = 50-60% HRpeak, HRZone2 = 60-70% HRpeak, HRZone3 = 70-76% HRpeak, HRZone4 = 77-84% HRpeak, and HRZone5 = 85-100% HRpeak. Training load was calculated with the summated-heart-rate-zone model (SHRZmod). There was a main effect of position (p ≤ 0.019) and quarter (p ≤ 0.005) on SHRZmod and on time spent in HRZone1-5. Athletes accumulated the most time in HRZone4 and HRZone5 and in the fourth quarter, and SHRZmod was the greatest in the fourth quarter. There was no main effect for HRavg and HRpeak (p ≥ 0.110). Athletes averaged 34.5 minutes per game competing in HRZone5 or ≥85% HRpeak with nearly one-third of those minutes accumulated in the fourth quarter. Although there were no differences in HRavg and HRpeak from quarter to quarter, SHRZmod increased from the first to fourth quarter. Utilizing time spent in heart rate zones and training load with SHRZmod can provide valuable information to practitioners regarding the intensity and physiological demands of competitive basketball games.


Asunto(s)
Baloncesto , Atletas , Femenino , Frecuencia Cardíaca , Humanos , Monitoreo Fisiológico
7.
J Sports Sci Med ; 19(1): 38-42, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32132825

RESUMEN

A functional single-nucleotide polymorphism (SNP) in the catechol-O-methyltransferase (COMT) gene (rs4680) is a gene variant that has been shown to predict the ability to maintain cognitive agility during combat and competition. Critically, COMT Met (low-activity; high dopamine) allele carriers outperform Val (high-activity; low dopamine) homozygotes on a variety of cognitive tasks. However, the relationship between genotype and cognitive performance appears to reverse under stressful conditions. Stress increases pre-frontal cortex dopamine (PFC DA) levels, and Met allele carriers (with higher DA) show performance deficits relative to Val allele carriers. This pattern reflects the inverted U-shaped function of DA activity where too little (Val allele) or too much (Met allele carriers under stress) DA is associated with poor cognitive performance. The Val allele advantage for stress resiliency is referred to as the COMT "warrior/ worrier" model. In line with this model, we predicted that elite level mixed martial arts (MMA) fighters would be more likely than athlete controls to carry the GG (warrior) genotype compared to an athlete group and a non-athlete group. Based on findings in our previous studies, we also assessed the stress biomarkers cortisol and salivary alpha-amylase (sAA). There was an overall significant difference in genotype frequencies between groups (p =0.01) and the MMA group showed a significantly greater GG (warrior) genotype frequency than the non-athlete control group (p = 0.003). There was not a significant group x genotype interaction for the cortisol or sAA; however, the non-athlete GG group had significantly higher cortisol than the A/- group (p = 0.038). Combined, our findings suggest that the "warrior" genotype may play a participation role in combat sports.


Asunto(s)
Catecol O-Metiltransferasa/fisiología , Cognición/fisiología , Artes Marciales/fisiología , Adulto , Agresión/fisiología , Dopamina/metabolismo , Genotipo , Humanos , Masculino , Metionina , Polimorfismo de Nucleótido Simple , Corteza Prefrontal/metabolismo , Transducción de Señal/fisiología , Valina , Adulto Joven
8.
J Strength Cond Res ; 34(7): 1974-1981, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29746384

RESUMEN

Sanders, GJ, Roll, B, Peacock, CA, and Kollock, RO. Maximum movement workloads and high-intensity workload demands by position in NCAA Division I collegiate football. J Strength Cond Res 34(7): 1974-1981, 2020-The purpose of the study was to quantify the average and maximum (i.e., peak) movement workloads, and the percent of those workloads performed at high intensity by NCAA Division I football athletes during competitive games. Using global positioning system devices (Catapult Sports), low, moderate, and high and total multidirectional movement workloads were quantified by each position. Strategically achieving maximal workloads may improve both conditioning and rehabilitation protocols for athletes as they prepare for competition or return to play after an injury. A total of 40 football athletes were included in the analysis. For the data to be included, athletes were required to participate in ≥75% of the offensive or defensive snaps for any given game. There was a total of 286 data downloads from 13 different games for 8 different football positions. Data were calculated and compared by offensive and defensive position to establish the mean, SD, and maximum workloads during competitive games. The percent high-intensity workload profile was established to assess the total number and percent of high-intensity movement workloads by position. The profile was calculated by dividing a position's maximal high-intensity movement workload by the total (e.g., sum of maximal low, moderate, and high-intensity movements) movement workload. One-way analysis of variances revealed that there was a main effect of football position for total movement workloads and the percent of workloads performed at high intensities (p ≤ 0.025 for all). Maximal high-intensity workloads were 1.6-4.3 times greater than average high-intensity workloads, and the percent of total workloads performed at high intensities varied greatly by position. Strategically training for and using maximal movement workloads can help ensure that athletes are achieving workloads that are similar to the greatest demands of a competitive game.


Asunto(s)
Fútbol Americano/fisiología , Movimiento/fisiología , Acondicionamiento Físico Humano/métodos , Adolescente , Atletas , Sistemas de Información Geográfica , Humanos , Masculino , Estudios Retrospectivos , Universidades , Adulto Joven
9.
J Int Soc Sports Nutr ; 16(1): 36, 2019 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-31477138

RESUMEN

BACKGROUND: Variations in the fat mass and obesity-associated gene (FTO) are associated with obesity; however, it is unclear if changes in energy intake affect the adaptive response to caloric restriction in those with risk variants. The three FTO single nucleotide polymorphisms (SNPs), rs1421085, rs17817449 and rs9939609, are in strong linkage disequilibrium. Thus, the purpose of this investigation was to determine the role of these FTO SNPs vis-à-vis the effects of a 4-week hypocaloric diet on body composition in exercise-trained men and women. Two salivary biomarkers that associate with energy expenditure were also assessed (cortisol and salivary alpha-amylase, sAA). METHODS: Forty-seven exercise-trained men (n = 11) and women (n = 36) (mean ± SD: age 32 ± 9 years; height 169 ± 8 cm, body mass index 24.5 ± 2.9 kg/m2, hours of aerobic training per week 4.9 ± 3.8, hours of weight training per week 3.9 ± 2.4, years of training experience 13.4 ± 7.0) completed a 4-week hypocaloric diet (i.e., decrease total calories by ~ 20-25% while maintaining a protein intake of ~ 2.0 g/kg/d). Subjects were instructed to maintain the same training regimen and to decrease energy intake via carbohydrate and/or fat restriction during the treatment period. Body composition was assessed via dual-energy X-ray absorptiometry (DXA) (Model: Hologic Horizon W; Hologic Inc., Danbury CT USA). Total body water was determined via a multifrequency bioelectrical impedance (BIA) device (InBody 770). Saliva samples were collected pre and post intervention in order to genotype the participants as well as to determine the concentrations of cortisol and sAA. RESULTS: Of the 47 subjects, 15 were of normal risk for obesity whereas 32 were carriers of the FTO gene risk alleles. Subjects were grouped based on their genotype for the three FTO SNPs (i.e., rs1421085, rs17817449 and rs9939609) due to their strong linkage disequilibrium. We have classified those with the normal obesity risk as "non-risk allele" versus those that carry the "risk allele" (i.e., both heterozygous and homozygous). Both groups experienced a significant decrease in total energy intake (p < 0.01); non-risk allele: pre kcal 2081 ± 618, post kcal 1703 ± 495; risk allele: pre kcal 1886 ± 515, post kcal 1502 ± 366). Both groups lost a significant amount of body weight (p < 0.01); however, there was no difference between groups for the change (post minus pre) in each group (risk allele change: - 1.0 ± 1.2 kg, non-risk allele change: - 1.2 ± 1.4 kg). Additionally, both groups lost a significant amount of fat mass (p < 0.01) with no differences between groups for the change in fat mass (risk allele change for fat mass: 1.1 ± 0.7 kg, non-risk allele change - 0.9 ± 0.4 kg). There were no significant changes in either group for fat free mass or total body water. The change in salivary alpha-amylase or cortisol was not different between groups. CONCLUSIONS: In the short-term (i.e., 4 weeks), exercise-trained men and women consuming a hypocaloric diet that is relatively high in protein experience similar changes in body composition due exclusively to a decrement in fat mass and independent of FTO allele status. Therefore, weight and fat loss on a hypocaloric diet is, at least in the short-term, unaffected by the FTO gene.


Asunto(s)
Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/genética , Restricción Calórica , Ejercicio Físico , Adulto , Alelos , Composición Corporal , Ingestión de Energía , Femenino , Humanos , Desequilibrio de Ligamiento , Masculino , Obesidad/genética , Polimorfismo de Nucleótido Simple , Adulto Joven
10.
J Sports Sci ; 37(19): 2236-2242, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31185823

RESUMEN

The purpose of the study was to assess factors that contribute to countermovement jump (CMJ) performance in women's basketball athletes. Thirteen female athletes participated and were tested for maximal oxygen uptake (VO2max) and heart rate (HRmax). Athletes were monitored, daily for a total of 21 weeks with heart rate-based wearable devices and CMJ performance and body weight were tested weekly after one day of recovery. 3-jump average height (CMJavg), maximum height jump (CMJmax), and CMJ power (Watts) were calculated and recorded. Playing intensities >85% HRmax, HRavg, HRmax and training load were averaged for three consecutive days prior to the recovery day. After the season, data was grouped as changes in CMJ power from week one: Large (≤ -4.39% change), Moderate (-4.4% to -0.62% change), and Minimal (≥ -0.61% change) changes. Fixed-effects models revealed a main effect of group (p ≤ 0.05) for CMJavg, CMJmax, VO2max, weekly percent changes in body weight and for 3-day training load, HRavg, and playing time at >85% HRmax. When athletes experienced minimal changes in CMJ performance, relative to large changes, they produced greater power, jumped higher, avoided negative changes in weekly body weight, had a greater preseason VO2max and 3-day average workloads appeared to have an impact on CMJ performance.


Asunto(s)
Rendimiento Atlético/fisiología , Baloncesto/fisiología , Conducta Competitiva/fisiología , Fatiga Muscular/fisiología , Adolescente , Peso Corporal , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Monitoreo Fisiológico/métodos , Consumo de Oxígeno/fisiología , Acondicionamiento Físico Humano , Aptitud Física/fisiología , Dispositivos Electrónicos Vestibles , Adulto Joven
11.
Sports (Basel) ; 7(1)2018 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-30577414

RESUMEN

The purpose of this investigation is to present observational data regarding sleep variables in professional Mixed Martial Arts (MMA) athletes. These sleep performance measures were related to physical performance and injury in MMA athletes. Eight professional athletes were placed into a quasi-controlled, multivariable fight-camp environment for a six-week period in preparation for fight competition. Throughout a six-week fight camp environment, athletes were continuously monitored for sleep performance measures (sleep latency, sleep efficiency, onset, and wake variances) via validated wearable sleep monitoring technology. Athletes were tested seven days prior to competition on measures of physical performance (vertical jump, VO2max, heart rate recovery, prowler sled push, and pull-ups). Multiple correlational analyses were utilized to assess relationships between all sleep and physical performance measures. There were significant (P < 0.05) correlations between sleep latency and VO2max, heart rate recovery, prowler sled push, vertical jump, and missed practice sessions. There were also significant (P < 0.05) correlations between average fall asleep time and heart rate recovery. Lastly, there were significant (P < 0.05) correlations between sleep efficiency, heart rate recovery, and missed practice sessions. MMA athletes who exhibited consistency in sleep demonstrated stronger relationships with performance testing during the fight-camp period.

12.
Sports (Basel) ; 6(3)2018 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-30213103

RESUMEN

The purpose of the study was to assess glycogen content of the rectus femoris (RF) muscles utilizing high-frequency ultrasound throughout an intensive, nine-day preseason training period in NCAA division I volleyball athletes. In the morning prior to the beginning of practice, athletes (n = 13) left and right RF muscles were assessed via ultrasound to quantify muscle fuel ratings (0⁻100 score range). The recommended location of the RF ultrasound scans were based on manufacturer guidelines, and the same technician recorded the daily measurements. To assess daily training load, session ratings of perceived exertion (s-RPE) were utilized. A paired t-test revealed a large significant difference between left (51.7 ± 17.9) and right (32.8 ± 17.4) RF muscle fuel ratings (p < 0.001). There was also a major effect of time on s-RPE (p < 0.001) and left (dominant) RF fuel rating (p = 0.001). s-RPE decreased from the beginning to the end of the training camp. However, left RF fuel ratings increased from the first to the second day, then remained elevated all throughout the preseason. In conclusion, all athletes were left-leg dominant and had a 57.6% bilateral asymmetry between their left and right RF muscle fuel ratings despite changes in training load. High-frequency ultrasounds are a noninvasive assessment tool that can determine glycogen replenishment asymmetries in the RF.

13.
Artículo en Inglés | MEDLINE | ID: mdl-29434529

RESUMEN

BACKGROUND: It has been posited that the consumption of extra protein (> 0.8 g/kg/d) may be deleterious to bone mineral content. However, there is no direct evidence to show that consuming a high-protein diet results in a demineralization of the skeleton. Thus, the primary endpoint of this randomized controlled trial was to determine if a high-protein diet affected various parameters of whole body and lumbar bone mineral content in exercise-trained women. METHODS: Twenty-four women volunteered for this 6-month investigation (n = 12 control, n = 12 high-protein). The control group was instructed to consume their habitual diet; however, the high-protein group was instructed to consume ≥2.2 g of protein per kilogram body weight daily (g/kg/d). Body composition was assessed via dual-energy x-ray absorptiometry (DXA). Subjects were instructed to keep a food diary via the mobile app MyFitnessPal®. Exercise or activity level was not controlled. Subjects were asked to maintain their current levels of exercise. RESULTS: During the 6-month treatment period, there was a significant difference in protein intake between the control and high-protein groups (mean±SD; control: 1.5±0.3, high-protein: 2.8±1.1 g/kg/d); however, there were no differences in the consumption total calories, carbohydrate or fat. Whole body bone mineral density did not change in the control (pre: 1.22±0.08, post: 1.22±0.09 g/cm2) or high-protein group (pre: 1.25±0.11, post: 1.24±0.10 g/cm2). Similarly, lumbar bone mineral density did not change in the control (pre: 1.08±0.16, post: 1.05±0.13 g/cm2) or high-protein group (pre: 1.07±0.11, post: 1.08±0.12 g/cm2). In addition, there were no changes in whole body or lumbar T-Scores in either group. Furthermore, there were no changes in fat mass or lean body mass. CONCLUSION: Despite an 87% higher protein intake (high-protein versus control), 6 months of a high-protein diet had no effect on whole body bone mineral density, lumbar bone mineral density, T-scores, lean body mass or fat mass.


Asunto(s)
Densidad Ósea , Dieta Rica en Proteínas , Proteínas en la Dieta/administración & dosificación , Fenómenos Fisiológicos en la Nutrición Deportiva , Absorciometría de Fotón , Adulto , Atletas , Composición Corporal , Dieta Rica en Proteínas/efectos adversos , Proteínas en la Dieta/efectos adversos , Ejercicio Físico , Femenino , Humanos
14.
J Strength Cond Res ; 31(10): 2728-2733, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28817506

RESUMEN

The purpose of the study was to quantify the average and maximum distances traveled by National Collegiate Athletic Association division I football athletes during competitive games. Using global positioning system devices (Catapult Sports), total and low-, moderate-, and high-speed distances were quantified by each position. Understanding maximal workloads can enhance conditioning practice periodization protocols. A total of 40 football athletes were included in the analysis. For the data to be included, athletes were required to participate in ≥75% of the offensive or defensive snaps for any given game. There was a total of 286 data downloads from 13 different games for 8 different football positions. Data were calculated and compared by offensive and defensive position to establish the mean, SD, and maximum distances (in meters) traveled during competitive games. A total maximum distance range (Max Range) was established to account for athletes who accumulated in-game total distances greater than the M + 1SD for each position. A percent was also calculated to highlight how often athletes accumulated distance workloads in the Max Range. One-way analysis of variance revealed there was a main effect of football position for all distance variables (p ≤ 0.001). Regardless of position, 12.0-16.7% of the time athletes accumulated in-game total distances in the Max Range. Conditioning and practice periodization protocols for distance should be position specific or individualized to avoid under or over conditioning. In addition, using a Max Range for distance can help ensure athletes are achieving distance workloads that are similar to the demands of a competitive game.


Asunto(s)
Atletas , Fútbol Americano/fisiología , Adolescente , Sistemas de Información Geográfica , Humanos , Masculino , Universidades , Adulto Joven
15.
Int J Exerc Sci ; 10(2): 197-204, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28344734

RESUMEN

Research is inconclusive regarding the association between aerobic fitness (objectively measured VO2max) and repeated sprint performance when the sprints are less than 40 meters. Soccer athletes must be able to repeat sprints without significant decreases in speed and strength and conditioning coaches need to better understand if aerobic fitness is related to repeated sprint ability (RSA). Twenty (10 male, 10 female) Division I soccer athletes first completed a graded maximal treadmill test to measure VO2max. Then on a separate day, athletes completed the RSA test. The RSA test consisted of 10, 30-meter sprints which athletes repeated every 30 seconds. There were significant negative correlations (r ≤ -0.69, P < 0.001) between VO2max and all 10-sprint times and average sprint time. More aerobically fit Division I soccer athletes were faster at all time points during the RSA test. Aerobic fitness is associated with faster sprint times during a more anaerobic RSA test when sprint distances are less than 40 meters.

16.
Int J Occup Saf Ergon ; 23(1): 44-49, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27617800

RESUMEN

BACKGROUND: Hypoxia is a physiological state defined as a reduction in the distribution of oxygen to the tissues of the body. It has been considered a major factor in aviation safety worldwide because of its potential for pilot disorientation. Pilots are able to operate aircrafts up to 3810 m without the use of supplemental oxygen and may exhibit symptoms associated with hypoxia. OBJECTIVE: To determine the effects of 3810 m on physiology, cognition and performance in pilots during a flight simulation. METHODS: Ten healthy male pilots engaged in a counterbalanced experimental protocol comparing a 0-m normoxic condition (NORM) with a 3810-m hypoxic condition (HYP) on pilot physiology, cognition and flight performance. RESULTS: Repeated-measures analysis of variance demonstrated a significant (p ≤ 0.05) time by condition interaction for physiological and cognitive alterations during HYP. A paired-samples t test demonstrated no differences in pilot performance (p ≥ 0.05) between conditions. CONCLUSION: Pilots exhibited physiological and cognitive impairments; however, pilot performance was not affected by HYP.


Asunto(s)
Medicina Aeroespacial , Cognición/fisiología , Hipoxia/fisiopatología , Pilotos , Adolescente , Adulto , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Análisis y Desempeño de Tareas
17.
J Nutr Metab ; 2016: 9104792, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27807480

RESUMEN

The purpose of this investigation was to determine the effects of a high protein diet over a one-year period. Fourteen healthy resistance-trained men completed the study (mean ± SD; age 26.3 ± 3.9 yr; height 178.5 ± 8.4 cm; and average years of training 8.9 ± 3.4 yr). In a randomized crossover design, subjects consumed their habitual or normal diet for 2 months and 4 months and alternated that with a higher protein diet (>3 g/kg/d) for 2 months and 4 months. Thus, on average, each subject was on their normal diet for 6 months and a higher protein diet for 6 months. Body composition was assessed via the Bod Pod®. Each subject provided approximately 100-168 daily dietary self-reports. During the subjects' normal eating phase, they consumed (mean ± SD) 29.94 ± 5.65 kcals/kg/day and 2.51 ± 0.69 g/kg/day of protein. This significantly increased (p < 0.05) during the high protein phase to 34.37 ± 5.88 kcals/kg/day and 3.32 ± 0.87 g/kg/day of protein. Our investigation discovered that, in resistance-trained men that consumed a high protein diet (~2.51-3.32 g/kg/d) for one year, there were no harmful effects on measures of blood lipids as well as liver and kidney function. In addition, despite the total increase in energy intake during the high protein phase, subjects did not experience an increase in fat mass.

18.
Work ; 54(3): 699-707, 2016 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-27315410

RESUMEN

BACKGROUND: Trips are common in and out of the workplace with most people recovering to avoid a subsequent fall. However, when the recovery attempt fails, a fall can be detrimental. OBJECTIVE: The purpose of this exploratory study was to examine adaptations to the elevating response during obstacle tripping while walking on a treadmill. Additionally, the possible transfer effects from adapted responses in the lab to the worksite are explored. METHODS: Fourteen healthy participants that covered the general working age range (20-70 yrs.) were presented with two different types of tripping obstacles while walking. RESULTS: Elevating the foot over the obstacle was expected due to all trips being induced during early swing phase (first 33% of the swing phase). However, in addition to the elevating strategy, a novel "push" strategy was observed in all but three participants. CONCLUSION: The current study provided support that obstacle type influences the behavioral response after a trip. Therefore, obstacles that catch the shoe should be considered when designing functional fall programs. Furthermore, information from the current study is useful for establishing guidelines when developing a fall prevention program in the workplace.


Asunto(s)
Accidentes por Caídas/prevención & control , Adaptación Fisiológica , Salud Laboral , Caminata/fisiología , Adulto , Anciano , Fenómenos Biomecánicos , Femenino , Marcha/fisiología , Humanos , Masculino , Persona de Mediana Edad , Lugar de Trabajo , Adulto Joven
19.
J Int Soc Sports Nutr ; 12: 39, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26500462

RESUMEN

BACKGROUND: The consumption of a high protein diet (>4 g/kg/d) in trained men and women who did not alter their exercise program has been previously shown to have no significant effect on body composition. Thus, the purpose of this investigation was to determine if a high protein diet in conjunction with a periodized heavy resistance training program would affect indices of body composition, performance and health. METHODS: Forty-eight healthy resistance-trained men and women completed this study (mean ± SD; Normal Protein group [NP n = 17, four female and 13 male]: 24.8 ± 6.9 yr; 174.0 ± 9.5 cm height; 74.7 ± 9.6 kg body weight; 2.4 ± 1.7 yr of training; High Protein group [HP n = 31, seven female and 24 male]: 22.9 ± 3.1 yr; 172.3 ± 7.7 cm; 74.3 ± 12.4 kg; 4.9 ± 4.1 yr of training). Moreover, all subjects participated in a split-routine, periodized heavy resistance-training program. Training and daily diet logs were kept by each subject. Subjects in the NP and HP groups were instructed to consume their baseline (~2 g/kg/d) and >3 g/kg/d of dietary protein, respectively. RESULTS: Subjects in the NP and HP groups consumed 2.3 and 3.4 g/kg/day of dietary protein during the treatment period. The NP group consumed significantly (p < 0.05) more protein during the treatment period compared to their baseline intake. The HP group consumed more (p < 0.05) total energy and protein during the treatment period compared to their baseline intake. Furthermore, the HP group consumed significantly more (p < 0.05) total calories and protein compared to the NP group. There were significant time by group (p ≤ 0.05) changes in body weight (change: +1.3 ± 1.3 kg NP, -0.1 ± 2.5 HP), fat mass (change: -0.3 ± 2.2 kg NP, -1.7 ± 2.3 HP), and % body fat (change: -0.7 ± 2.8 NP, -2.4 ± 2.9 HP). The NP group gained significantly more body weight than the HP group; however, the HP group experienced a greater decrease in fat mass and % body fat. There was a significant time effect for FFM; however, there was a non-significant time by group effect for FFM (change: +1.5 ± 1.8 NP, +1.5 ± 2.2 HP). Furthermore, a significant time effect (p ≤ 0.05) was seen in both groups vis a vis improvements in maximal strength (i.e., 1-RM squat and bench) vertical jump and pull-ups; however, there were no significant time by group effects (p ≥ 0.05) for all exercise performance measures. Additionally, there were no changes in any of the blood parameters (i.e., basic metabolic panel). CONCLUSION: Consuming a high protein diet (3.4 g/kg/d) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition. Furthermore, there is no evidence that consuming a high protein diet has any deleterious effects.


Asunto(s)
Composición Corporal/efectos de los fármacos , Proteínas en la Dieta/administración & dosificación , Entrenamiento de Fuerza , Tejido Adiposo , Adolescente , Adulto , Peso Corporal , Ingestión de Energía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Adulto Joven
20.
Games Health J ; 4(4): 265-70, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26182213

RESUMEN

OBJECTIVE: Nintendo(®) (Kyoto, Japan) "Wii™ Sports Boxing" ("Wii Boxing") and Xbox(®) (Microsoft, Redmond, WA) "Kinect(®) Sports Boxing" ("Kinect Boxing") are both boxing simulation videogames that are available for two different active videogame (AVG) systems. Although these AVGs are similar, the style of gameplay required is different (i.e., upper body only versus total body movements) and may alter physical activity intensity and one's preference for playing one game over the other. AVGs that elicit the greatest physiologic challenge and are preferred by users should be identified in an effort to enhance the efficacy of physical activity interventions and programs that include AVGs. MATERIALS AND METHODS: The mean heart rate (HRmean) and peak heart rate (HRpeak) for 27 adults (22.7±4.2 years old) were recorded during four 10-minute conditions: seated rest, treadmill walking at 3 miles/hour, "Wii Boxing," and "Kinect Boxing." Upon completion of all four conditions, participants indicated which condition they preferred, and HRmean and HRpeak were calculated as a percentage of age-predicted maximum heart rate to classify physical activity intensity for the three activity conditions (treadmill, "Wii Boxing," and "Kinect Boxing"). RESULTS: "Kinect Boxing" significantly (P<0.001) increased percentage HRmean (64.1±1.6 percent of age-predicted maximum) and percentage HRpeak (76.5±1.9 percent) above all other conditions: Wii HRmean, 53.0±1.2 percent; Wii HRpeak, 61.8±1.5 percent; treadmill HRmean, 52.4±1.2 percent; treadmill HRpeak, 55.2±2.2 percent. Percentage HRpeak for "Kinect Boxing" was great enough to be considered a vigorous-intensity physical activity. There was no difference (P=0.55) in percentage HRmean between "Wii Boxing" and treadmill walking. Participants also preferred "Kinect Boxing" (P<0.001; n=26) to all other conditions ("Wii Boxing," n=1; treadmill n=0). CONCLUSIONS: "Kinect Boxing" was the most preferred and the only condition that was physiologically challenging enough to be classified as a vigorous-intensity physical activity.


Asunto(s)
Boxeo/fisiología , Juegos de Video/psicología , Caminata/fisiología , Adolescente , Adulto , Boxeo/psicología , Frecuencia Cardíaca/fisiología , Humanos , Satisfacción Personal , Estudiantes , Juegos de Video/clasificación , Caminata/psicología
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