Dehydration during and after exercise is prevalent in athletes. Due to a thirst mechanism that does not entirely replenish total body water lost during exercise, it is crucial to rehydrate efficiently with sufficient fluids and electrolytes to retain fluid intake. The study aimed to observe the effectiveness of rehydration with different commercially available drinks and plain water. The rehydration was assessed over 4 hours after a 2% exercise-induced dehydration in the heat. Rehydration was equal to 150% of fluid loss via exercise and was administered in four equal doses during the first 60 minutes of the rehydration period. The average exercise-induced dehydration was 2.11 ± 0.4%. The high sodium and potassium-containing drink, GoodSport, had significantly better rehydration at the four-hour time point (-0.44 ± .21) than in Gatorade (-0.71 ± 0.16; P = 0.0273), Body Armor (-1.00 ± 0.5; P < 0.0001), and water (-0.88 ± 0.39; P = 0.0015). Similarly, GoodSport resulted in lower urinary output than the other drinks. Results from this study indicate that the intake of a high sodium and potassium-containing sports drink after exercise improves net fluid balance more than drinks with lower electrolyte concentrations.

Nutritional supplements (the combination of dietary supplements, sports foods, and performance-enhancing supplements) are used by many athletes for health and/or performance-related reasons. Nutritional supplements may be contaminated with illegal substances, putting the athlete at risk of adverse health outcomes or a positive doping test. Third-party testing programs help mitigate risk by regulating the purity and safety of supplements. However, it is unknown what percentage of high school athletes are familiar with third-party testing programs and how many athletes use such programs. This study was designed to explore high school athletes’ use of nutritional supplements, whether they were third-party tested, and their attitudes and influences toward safe(r) nutritional supplement use. An online questionnaire was developed to distribute among student-athletes from a private high school in the western US, resulting in a representative sample (n=225). Ninety-four percent (n = 211) of the student-athlete population reported using at least one nutritional supplement within the past year, reporting six different supplements on average. Sports foods were used the most (87%), followed by dietary supplements (76%), and then supplements claiming to enhance performance (58%). The most frequently reported nutritional supplements were sports drinks (72%), vitamins (65%), sports bars (60%), protein powder (58%), recovery drinks (46%), and multivitamin/mineral supplements (40%). One-fourth of student-athletes reported consistent use of third-party tested supplements. Reasons for supplement use include gaining muscle (48%), improving health (46%), improving performance (44%), and losing or gaining weight (29%). Parents (45%) had the most influence on the athlete’s purchasing of supplements, followed by friends, teammates, or other family members (40%), the physician (30%), head sports coach (26%), strength and conditioning coach (25%), and athletic trainer (24%). The sports dietitian was checked by 8% of students as influential. The biggest gap in knowledge was where to find third-party tested supplements (22% knowledgeable) and where to order third-party tested supplements (25% knowledgeable). Based on the results, high school athletes would likely benefit from increased education regarding third-party testing programs and should increase their knowledge of where to find and purchase third-party tested supplements.

Nutritional supplement use by high school student athletes may pose risks of consuming prohibited or banned substances that can result in suspension of athletic participation. Currently, there is no peer-reviewed published data that exists on the use of supplements and use of third-party tested supplements for this population. When looking at supplement use, the Theory of Planned Behavior (TPB) can be utilized. This model was designed to determine if the intention of completing a behavior is based on three different constructs which include attitude, subjective norm, and perceived behavioral control. A pre- and post- test questionnaire was used to determine the effect of an educational intervention that was designed and developed. A total of 106 high school student athletes, ranging from 14-19 years of age from a private high school in the western US were included in the analysis of the study. The intention to use a good basic diet and intention to use nutritional supplements were both predicted by attitude, subjective norm, and perceived behavioral control and both resulted in a significant regression equation (p < .001). There was 95.3% (n=101) of athletes that reported use of at least one supplement in the last 12 months with reporting on average eight supplements ranging from 0-31 supplements. In conclusion, almost all high school student athletes reported using at least one nutritional supplement in the last 12 months, while roughly one-fourth consistently reported to use third-party tested nutritional supplements. The TPB based supplement education program resulted in the intention to change supplement behavior toward using safe third-party tested supplements more frequently at a group level.

Sleep is an essential biological requirement to sustain human life and a critical component for athletes. There has been a rising trend for poor sleep in the general population and the problem persists as well within the athletic population. Research has demonstrated numerous benefits of optimized sleep on athletic performance and athlete wellness. Further investigation of potential dietary strategies to improve self-perceived sleep quality is warranted. This study examined the differences in perceived sleep quality and wellness between a 3-week baseline period and after a 3-week supplementation period, in which participants consumed a dietary supplement containing fermented whey protein + galacto-oligosaccharides (GOS) + casein protein daily. Validated questionnaires, namely, Athens Insomnia Scale (AIS), Physical Health Questionnaire (PHX), Kessler-6 Mental Stress Scale (K6) were used to measure perceived sleep quality and wellness on Day 1, Day 22 and Day 43. Additionally, multiple 24-h dietary recalls (ASA24), and food quality using the validated Rapid Eating Assessments for Participants (REAP) questionnaire, were used to assess dietary patterns throughout the study, while exercise occurrence was tracked through a self-developed daily questionnaire. A total of 54 healthy active adults (age=18-35yrs) experiencing gastro-intestinal (GI) complaints were included in the trial, and 50 participants were included in the final analysis. Significantly lower AIS-8 total scores were found on Day 43 compared to Day 22 while controlled for Day 1 (Day 43: 4.36 ± 3.68 versus Day 22: 5.02 ± 4.11, F=4.379 (1, 50), p=0.042), while no differences were found for wellbeing (p≥ 0.180). Dietary intake, food quality and exercise frequency did not change over time (p≥0.080). These results suggested that a daily protein + GOS supplement was associated with a decrease in AIS-8 total scores suggesting improved perceived sleep quality among athletes after 3 weeks. A controlled research study should confirm these results in the future. More research is required to assess the effects of protein + prebiotic supplementation on sleep parameters among athletes.

Gastrointestinal (GI) complaints are prevalent among athletes. Fermented foods with pre-or probiotic features may relieve GI symptoms by improving gut health. This study aimed is to examine the impact of a nutritional supplement containing fermented whey protein with Galacto-oligosaccharide (GOS) fiber on GI distress among well-trained athletes over time by analyzing self-reported GI complaints without a control group. This quasi-experimental clinical trial consisted of a 3-week baseline period, reflected by two baseline measurements on Day 1 and Day 22, which was followed by a 3-week intervention period, reflected by a post-intervention measurement on Day 43, in which athletes added 15g of a fermented whey protein product to their diet. The primary outcome was based on the self-reported gastrointestinal symptom rating scale (GSRS), and the secondary outcome was based on a daily questionnaire, in which daily GI complaints and exercise occurrences were reported. Tertiary outcomes included a 24-hour diet recall (ASA24) and self-reported diet quality (REAP). Outcomes obtained during baseline (Day 1 and Day 22 average) were compared to those post-intervention (Day 43). Statistical significance was set at P<0.05. A total of n=50 athletes (24.7±4.5 years) with GI issues were included in the study. Five individual items of the GSRS including abdominal pain, acid reflux, bloating, burping, and loose stools reflected significantly lower scores on Day 43 in comparison to baseline (P≤0.028). A total of 78% reported GI complaints at baseline, and 61% of the participants reported lower GI complaints on Day 43 after supplementation in comparison to baseline (P=0.004). Further research is needed to explore the potential benefits of a hydrolyzed and fermented whey protein with prebiotics in a more controlled setting among athletic populations.

The human body has temperature-regulating mechanisms working to maintain body core temperature around 37°C. This ensures optimal bodily function. Disruption to core temperature however, initiates a cascade of events to return to baseline. The objective of this study is to evaluate the efficacy of cooling strategies to induce the fastest reductions in core temperature. The study was set up as a randomized field study. Core temperature was measured using an E-Celsius core temperature capsule. Environmental conditions were measured using a Kestrel heat stress tracker. Following completion of a heat-stress protocol, participants underwent one of the four randomized cooling protocols. These cooling protocols consisted of: 1) wearing an ice vest (18°C), 2) applying an icy towel directly to the back of the neck (24°C) in combination with hand/forearm water immersion (15°C), 3) a combination of ice vest, icy towel and hand/forearm water immersion, or 4) sitting in a thermoneutral room (20°C). In all cooling interventions, participants consumed 16oz of an ice slurry (0°C) within 10 minutes of the initiation of the protocol. The control group consumed only room temperature water- ad libitum. A total of 10 active males (25 ± 3 years old) reported no difference between baseline body core temperatures after each heating intervention (P=0.23). Average core temperature and heart rate differed, though not statistically significant between treatments (P>0.05). No significant differences were noted between cooling rates (P=0.51). Skin temperature (Tsk) average and decrement was found to be statistically significant (P<0.001).

Heat acclimatization can be induced by targeting a core temperature 38.5°C for at least 60 minutes per day lasting 5 to 21 days, complementary to normal exercise activity. However, consistently meeting this threshold on consecutive days may be difficult for athletes. The objective of this study was to evaluate the efficacy of four single-bout heating protocols to reach a core temperature 38.5°C. The study was set up as a non-randomized field study, factoring in the September-October outdoor desert conditions, Tempe, AZ, USA. Environmental conditions were measured using a Kestrel heat stress tracker. Protocols were constituted out of 3 elements: PAS – passive heat exposure in a tent (54±1°C), EH - exercise in hot condition with high intensity interval training (HIIT) outdoors in the heat in a tent with a ventilator (43±1°C), EM – exercise in moderate conditions with HIIT indoors (22±0.4°C). All participants performed protocols in the following order: 1) PAS 60-min; 2) EH-PAS (EH 30-min + PAS 30-min); 3) EH 60-min, and 4) EM 60-min. A cycle ergometer was used for HIIT (2-min warm-up followed by 7x2-min sprints with 2-min relative rest between sprints during the first 30 min and stationary cycling for the second 30 min), with a self-selected workload at 80-100 rpm and similar heart rate (HR) response during exercise testing for EH: 146±10, EM: 142±13, and EH-PAS: 142±13 (P>0.05). A total of 10 active male students (25±3 years old) reported no difference between protocols for baseline Tc (P=0.37) and HR (P=0.28). During the first 30-min, Tc was significantly different between protocols (average ranging from 37.3-37.6°C, P=0.01), but from a practical perspective, differences were limited. During the second 30-min session, the Tc for EH (38.5±0.4°C) and EH-PAS (38.6±0.4°C) were significantly higher from EM (38.1±0.4°C) and PAS alone (37.8±0.4°C), P<0.001. The average HR (bpm) was significantly lower in PAS (110±17) and EH (136±13) during the second half of the protocols compared to the EH (151±10) and EM (149±16), P<0.001. In conclusion, exercise alone vs. a combination of exercise and passive heating in hot conditions resulted both in a body temperature 38.5°C, but the combination was more efficient since participants exercised for only 30-minutes.

The purpose of this study was to evaluate the impact of improved hydration on endurance performance and mood in physically active adults. Participants (n = 72; age, 21.0 ± 3.0; 22.2% female) completed two two-mile run trials separated by exactly a week. Before each trial, participants provided a urine sample from the day before the run and a sample from the morning of the run. These samples were analyzed for urine osmolality (UOsm), urine specific gravity (USG), and urine color (Ucol). UOsm and USG levels determined if the participants were placed in either the euhydrated or underhydrated group after the first trial. Those assigned to the euhydrated group were instructed to maintain their current fluid intake levels and those in the underhydrated group were instructed to increase fluid intake levels before the second trial. However, results were grouped by if they improved or maintained their hydration or not. The subjects also completed a Profile of Mood States (POMS) questionnaire before and after each trial to determine mood. Based on conditioning requirements for group assignment, 38% of subjects were classified as underhydrated. There were significant differences between the two trials for both subjects that improved and worsened their hydration in UOsm, USG, Ucol, and thirst (P < 0.05). The group with improved hydration ran -15 ± 67 sec faster in the second trial, while the group that worsened hydration ran 4 ± 26 sec slower in the second trial. When these differences were compared between the two groups with a t-test, there was a trend for statistical differences with a one-way t-test analysis (P = 0.06). When results were split by sex no statistically significant differences were observed (male: -10.8 ± 63.6 sec; female: -29.4 ± 94.8 sec; P > 0.05). Improved hydration did not result in statistically significant difference in TMD or any of the individual mood sub-scales for either group for both males and females (P > 0.05). In conclusion, increased fluid intake to optimize hydration status may affect endurance exercise in young, healthy adults in a two-mile run, but no effect was seen on mood.

Water is an essential nutrient that is often overlooked. As a result of this hydration status is often forgotten as well. Becoming hypohydrated puts athletes at risk of decreased performance and potentially life-threatening heat illness. Being able to self-assess hydration status is may be instrumental in helping athletes safely optimize performance. Therefore, this study investigated, 1) the ability of an athletic population vs. trained investigators to self-diagnose underhydration, 2) the diagnostic ability of urine color (Ucol) charts as a method for diagnosing underhydration, and 3) the accuracy of participant and investigator assessments. Members of an athletic population each provided a urine sample and scored samples using both the traditional 8-color and newly developed 7-color Ucol chart. Investigators then scored the samples using the same methods. To determine the diagnostic value of the Ucol charts, Ucol scores were compared to concentration measures of Urine Specific Gravity (USG) and Urine Osmolality (Uosm). Differences in participant and investigator scores were compared using Mann-Whitney U and Spearman’s Correlation. Bland-Altman plots were drawn to assess individual differences in reporting against the mean of the two methods. Receiver Operating Characteristic (ROC) analysis was used to both determine the ability of both charts to diagnose underhydration and to determine how well participants and investigators can determine their level of hydration. Athletes reported Ucol significantly lighter compared to investigators. Investigators showed no difference in reporting between the two charts but, athletes reported less than a color shade difference. The charts performed fair (8-color) to good (7-color) at diagnosing hypohydration. Athletes reported with less accuracy compared to investigators, and Ucol classification was found to be more accurate when compared to USG. Ucol charts are a practical tool to determine hydration status. Ucol scoring is similar regardless of the type of chart used. Trained investigators reported with slightly higher accuracy on both charts compared to untrained athletes. Athletes score Ucol fair to good in comparison to investigators. Ucol scoring is similar regardless of the type of chart used. The diagnostic ability of both Ucol charts is good in relation to USG. With education, athletes may be able to improve scores.

Annually, more than 200 hikers are rescued in the greater Phoenix area. This study examined behavior influencing acute hydration status in hot (HOT) and moderate (MOD) climates, by examining fluid planning and decision making in combination with an educational video. A total of n=115 hikers completed self-paced hikes, n=56 hikers completed the hike in a HOT condition (wet bulb globe temperature [WBGT]=24.84°C) and n=59 hikers completed the hike in a MOD condition (WBGT=8.28°C). Real food and fluid behavior allowed participants to freely select the amount of food and fluid brought on the hike and intake was ad libitum. The following heat stress indicators were all significantly higher in the HOT condition compared to MOD condition (HOT median, MOD median; p-value): hike duration (1.48, 1.20; p<0.01), energy expenditure (561, 408, p<0.01), sweat rate (776, 465, p<0.01), and session rating of perceived exertion (RPE) scores (1177, 732, p<0.01). After watching a 3-minute hydration education video, and the opportunity to stock up on extra fluid, 54% of participants carried sufficient fluid in the HOT condition to meet their needs compared to 81% of participants in the MOD condition. However, only 23% of participants in the HOT condition consumed sufficient fluid to make up for fluid lost through sweating compared to 33% in the MOD condition. More than half of participants in the HOT condition (59%) and the MOD condition (76%) did not stock up on extra fluid after education. These results demonstrate that hikers did not consume sufficient fluids to meet their needs while hiking, especially in a hot climate. They also show heat stress negatively affected hikers’ performance measures. More research is required to assess the feasibility and efficacy of hydration related education videos at trailheads.