Intrinsic Fatigue & Its Relation to Workload

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Description
The study aimed to determine the relationship of subjective perception of wellness (Intrinsic Fatigue) and Global Positioning Satellite derived workload amongst elite high school soccer players. Twenty-nine (16.4 ± 1.54 years) male participants completed a mobile app-based wellness questionnaire comprising…

The study aimed to determine the relationship of subjective perception of wellness (Intrinsic Fatigue) and Global Positioning Satellite derived workload amongst elite high school soccer players. Twenty-nine (16.4 ± 1.54 years) male participants completed a mobile app-based wellness questionnaire comprising of 6 subjective markers prior to 10 workload variables being measured by STATSports 10Hz GPS units later that same day. Only instances where both wellness and GPS reports qualified for analyses (N=231 exposures). No significant differences were reported in reported wellness within- or between-weeks (p > 0.05) with average Effect Sizes (ES) ranging from 0.001 to 0.15. Total Distance (TD) was significantly different (p < 0.05) within week. All GPS variables except TD and Distance per Minute (DpM) were significantly different (p < 0.05) between-weeks. Average GPS ES sizes ranged from 0.02 to 0.58. Wellness and GPS or it’s ESs were not correlated, with correlations ranging from -1.000 to 0.207. The results suggest monitoring of GPS reports to be a practical method of monitoring variation in player workload but does not support subjective questionnaires as a means of monitoring player wellness reflecting these workload variations in youth populations.
Date Created
2020
Agent

Relationship of Nutrition Knowledge and Dietary Intake Among Collegiate Female Athletes

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Description
The assessment and evaluation of dietary intake and nutrition knowledge in female athletes is especially important due to the high prevalence of inadequate intake in this population (Black et al., 2019). This study evaluated 1) the relationship of nutrition knowledge…

The assessment and evaluation of dietary intake and nutrition knowledge in female athletes is especially important due to the high prevalence of inadequate intake in this population (Black et al., 2019). This study evaluated 1) the relationship of nutrition knowledge and dietary intake among collegiate female athletes at the National Collegiate Athletic Association (NCAA) Division I, National Junior College Athletic Association (NJCAA), and Club sport levels and 2) the impact of competition level on this relationship as well. Participants (NCAA DI, n=51; NJCAA, n = 36; Club, n = 37) in this study answered two questionnaires, the Nutrition Sport Knowledge Questionnaire (NSKQ) and the Rapid Eating Assessment for Participants (REAP) questionnaire to assess knowledge and dietary intake. Participants also provided anthropometric and demographic information. The NSKQ was scored as a whole and for each of the four subcategories. REAP was scored both by tallying the number of “usually/often” frequency responses and given a numeral score to estimate diet quality. Statistical analysis was conducted using Kruskal-Wallis, Chi-square and Spearman’s correlation tests to compare differences within subgroups of participants and evaluate any relationships that may exist between nutrition knowledge and dietary intake with significance set at p≤0.05. Differences in nutrition knowledge between competition groups were significant, H(2)= 16.94, p< 0.001. NCAA DI (p<0.001) and Club (p<0.001) athletes had higher nutrition knowledge than athletes at the NJCAA level. This was true for overall knowledge as well as knowledge subcategories. However, minimal relationships between nutrition knowledge and dietary intake were found. The overall correlation value was rs(118)= -0.10 (95%CI: -0.28 to 0.08), p>0.05. This suggests those with higher nutrition knowledge did not necessarily have better dietary intake. Improvements in the assessment of nutrition knowledge and quick assessment of dietary quality and the relation between both is needed.
Date Created
2020
Agent

Effect of Specific Macronutrients On Competitive Golf Performance

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Description

This study aimed to investigate the effects of specific macronutrient feedings on competitive golf performance and perceived levels of fatigue and alertness. Participants played three, nine hole rounds of golf, consuming an isocaloric beverage as a control (CON), with the…

This study aimed to investigate the effects of specific macronutrient feedings on competitive golf performance and perceived levels of fatigue and alertness. Participants played three, nine hole rounds of golf, consuming an isocaloric beverage as a control (CON), with the addition of carbohydrate (CHO), or combination of protein and carbohydrate (COM). Physiological and performance measurements were taken before, during, and following each nine hole round. Performance measurements include driving accuracy (DA), driving distance (DD), iron accuracy (IA), chipping accuracy (CA), and putting accuracy (PA). Pre-golf hydration status (urine specific gravity [USG]) and Sweat Rate during golf performance showed no significant differences between trials. All nine hole rounds were performed in ~2 hours. Environmental conditions were similar for all three testing days (mean WBGT=10.946). No significant differences were seen in Driving Distance, Driving Accuracy, and Iron Accuracy for all nine holes between groups receiving different macronutrient feedings. Chipping Accuracy was significantly better in CON trial compared to CHO (p=0.004) and COM (p=0.019). No significant differences were seen in putting make percentages. COM trial significantly lowered Perceived Levels of Fatigue (p=0.019) compared to CON. The CHO trial showed significant improvements in DA compared to CON (13.7 vs. 44.1, p=0.012) and COM (13.7 vs. 33.6, p=0.004) in the first four holes. In the last five holes, the COM trial showed significant improvements in DA compared to CHO (17.5 vs. 29.7, p=0.007). Low Handicap golfers (3 +/- 3) performed significantly better than High Handicap golfers (14 +/- 3.6) in DD (265 vs. 241, p<0.001), DA (15.0 vs. 29.3, p=0.004), IA (15.2 vs. 25.2, p<0.001), CA (52.0 vs. 61.5, p=0.027), and PA 5ft (64% vs. 40%, p=0.003). High Handicap players showed no significant differences between the three trials for any golf performance measurements. Low Handicap players showed significant improvements in DA for COM trial compared to CON trial (13.6 vs. 27.6, p=0.003). The results suggest that carbohydrates at the start and a combination of carbohydrate and protein is beneficial at the second part of 9 holes to improve golf performance and maintain levels of fatigue, however, it needs to be investigated how this knowledge will relate to playing more holes.

Date Created
2020
Agent

Dietary Intake Behaviors of Recreational Mountain Hikers Climbing "A" Mountain in Summer and Fall

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Description
More than 200 hikers are rescued annually in the greater Phoenix area. This study

examined the impact of hiking in hot (HOT), dry temperatures versus moderate (MOD)

temperatures on dietary intake behaviors as well as markers of heat stress. Twelve

recreational mountain hikers…

More than 200 hikers are rescued annually in the greater Phoenix area. This study

examined the impact of hiking in hot (HOT), dry temperatures versus moderate (MOD)

temperatures on dietary intake behaviors as well as markers of heat stress. Twelve

recreational mountain hikers climbed “A” Mountain four consecutive times (4-miles) on

a HOT day (WBGT=31.6 °C) and again on a MOD day (WBGT= 19.0 °C). Simulated

food and fluid behavior allowed participants to bring what they normally would for a 4-

mile hike and to consume both ad libitum. The following heat stress indicators (mean

difference; p-value), were all significantly higher on the HOT hike compared to the MOD

hike: average core temperature (0.6 °C; p=0.002), average rating of perceived exertion

(2.6; p=0.005), sweat rate (0.54; p=0.01), and fluid consumption (753; p<0.001). On the

HOT hike, 42% of the participants brought enough fluids to meet their individual

calculated fluid needs, however less than 20% actually consumed enough to meet those

needs. On the MOD hike, 56% of participants brought enough fluids to meet their needs,

but only 33% actually consumed enough to meet them. Morning-after USG samples

≥1.020 indicating dehydration on an individual level showed 75% of hikers after the

HOT hike and 67% after the MOD hike were unable to compensate for fluids lost during

the previous day’s hike. Furthermore, participant food intake was low with only three

hikers consuming food on the hot hike, an average of 33.2g of food. No food was

consumed on the MOD hike. These results demonstrate that hikers did not consume

enough fluids to meet their needs while hiking, especially in the heat. They also show

heat stress negatively affected hiker’s physiological and performance measures. Future

recommendations should address food and fluid consumption while hiking in the heat.
Date Created
2020
Agent

Sun Radiation in Moderate Environmental Conditions Does Not Affect Fluid Balance in Female Collegiate Soccer Players

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Description
Exposure to sun radiation (SUR) with ambient temperature may be an influencer on athletes’ sweat loss in different environments, but the results are not currently known. The purpose of this study was to determine the effects of SUR on fluid…

Exposure to sun radiation (SUR) with ambient temperature may be an influencer on athletes’ sweat loss in different environments, but the results are not currently known. The purpose of this study was to determine the effects of SUR on fluid balance (FB) and hydration status (HS) in athletes exercising indoors and outdoors.

Initial FB and HS were assessed in NCAA-DI female soccer athletes (n=10) of a single team in temperate, dry conditions (55-68°F, 18-48% humidity) who were monitored during 3 practices of equal estimated energy expenditure (EE): two outdoors in direct SUR (cold/moderate temperatures) and one indoors without SUR (moderate temperatures). Humidity, temperature, and wet bulb globe temperature (WBGT – a measurement partly based on SUR, including ambient temperature/relative humidity) were recorded using Heat Stress Meters placed in the direct sun or in the shade. Each athlete’s semi-nude dry body weight was recorded before and after exercise. Urine samples were taken before, after, and the morning after. Urine specific gravity (USG) was tested to assess HS. Athletes wore combined heart rate and activity monitors to estimate EE and were provided ad libitum water and/or a zero-calorie sports drink. Their total intake included weights of consumed food and drink. Sweat rate was calculated using body weight change and intakes of liquids minus urine losses/hour.

Two-way repeated measures ANOVA analyzed group-level differences. No significance was found in total FB (1.01±0.32 L/hr) or EE/hr (444±97.1 kcal/hr) across all days (p>0.05). In analyzing individual athlete results, 40% had consistent USG >1.025 (p=0.001) suggesting potential dehydration. These 4 athletes selected water as their beverage, of which is known that consuming only water does not stimulate drinking behavior as does electrolyte drinks. The remaining 60% were overall not dehydrated (USG <1.025) but must be aware of incidental dehydration in hotter temperatures.

The conclusion is that in low-moderate temperatures, athletes self-regulate drinking habits and achieve fluid balance during exercise with or without sun radiation. However, athletes with average USG >1.025 are likely to remain dehydrated in moderate temperatures. The findings suggest that more education would benefit these athletes by ensuring hydration in any environment.
Date Created
2019
Agent

Heat Stress Degrades Hiking Performance

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Description

This study investigated the effect of environmental heat stress on physiological and performance measures during a ~4 mi time trial (TT) mountain hike in the Phoenix metropolitan area. Participants (n = 12; 7M/5F; age 21.6 ± 2.47 [SD]) climbed ‘A’…

This study investigated the effect of environmental heat stress on physiological and performance measures during a ~4 mi time trial (TT) mountain hike in the Phoenix metropolitan area. Participants (n = 12; 7M/5F; age 21.6 ± 2.47 [SD]) climbed ‘A’ mountain (~1 mi) four times on a hot day (HOT; wet bulb globe temperature [WBGT] = 31.6°C) and again on a moderate day (MOD; WBGT = 19.0°C). Physiological and performance measures were made before and throughout the course of each hike. Mean pre-hike hydration status (urine specific gravity [USG]) indicated that participants began both HOT and MOD trials in a euhydrated state (1.016 ± 0.010 and 1.010 ± 0.008, respectively) and means did not differ significantly between trials (p = .085). Time trial performance was impaired by -11% (11.1 minutes) in the HOT trial (105 ± 21.7 min), compared to MOD (93.9 ± 13.1 min) (p = .013). Peak core temperatures were significantly higher in HOT (38.5 ± 0.36°C) versus MOD (38.0 ± 0.30°C) with progressively increasing differences between trials over time (p < .001). Peak ratings of perceived exertion were significantly higher in HOT (14.2 ± 2.38) compared to MOD (11.9 ± 2.02) (p = .007). Relative intensity (percent of age-predicted maximal heart rate [HR]), estimated absolute intensity (metabolic equivalents [METs]), and estimated energy expenditure (MET-h) were all increased in HOT, but not significantly so. The HOT condition reduced predicted maximal aerobic capacity (CRFp) by 6% (p = .026). Sweat rates differed significantly between HOT (1.38 ± 0.53 L/h) and MOD (0.84 ± 0.27 L/h) (p = .01). Percent body mass loss (PBML) did not differ significantly between HOT (1.06 ± 0.95%) and MOD (0.98 ± 0.84%) (p = .869). All repeated measures variables showed significant between-subjects effects (p < .05), indicating individual differences in response to test conditions. Heat stress was shown to negatively affect physiological and performance measures in recreational mountain hikers. However, considerable variation exists between individuals, and the degree of physiological and performance impairment is probably due, in part, to differences in aerobic fitness and acclimatization status rather than pre- or during-performance hydration status.

Date Created
2019
Agent
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