Efficacy of an Educational Intervention for Improving the Hydration Status of Female Collegiate Indoor-Sport Athletes

Proper hydration allows the body to function at an optimal level.¹ Although the effects of body fluid loss may vary on an individual basis, body mass (BM) losses of sweat >2% led to performance deficits, ranging from decreases in cognitive function to decreases in sport-specific skills.^1–5 Although recommendations for proper hydration practices have been created for athletes,^1,6,7 these guidelines may not have been followed appropriately, based on the incidence of dehydration. Prepractice dehydration is very common in athletes at all competition levels.^8–15 Exercise-induced dehydration is also frequent in athletes due to increased sweat losses and improper fluid intake during or after those sweat losses.^8,16–19 To date, much of the research^15–18 has focused on the hydration practices of outdoor-sport athletes, which has shown that these athletes exhibit prepractice dehydration. The few investigators^11,20,21 who assessed indoor-sport athletes demonstrated that sweat rates were high and dehydration was still prevalent. This was especially true in basketball players due to the intermittent nature of play.^21,22 Regarding volleyball players, only 1 group⁹ examined the hydration status of adolescent athletes in a non–air-conditioned facility. Therefore, the hydration knowledge and practices of female collegiate indoor-sport players are unknown, as is the effectiveness of an educational intervention in improving hydration knowledge and habits.

Studies focused on improving hydration status and knowledge in female indoor athletes, especially collegiate volleyball and basketball athletes, remain limited. Previous authors^23,24 claimed that hydration education was an optimal tool for improving the hydration status of athletes, and a recent position statement¹ recommended educating physically active individuals to reduce the incidence of severe hypohydration and exercise-associated hyponatremia (EAH). Therefore, educational interventions could have positive implications for the hydration status of indoor-sport athletes. However, no researchers have examined the efficacy of an educational intervention for collegiate female indoor-sport athletes. Therefore, the purpose of our study was to determine whether 1 educational session on hydration would improve the hydration status and fluid intake of collegiate female indoor-sport athletes. We hypothesized that these athletes would arrive at practice hypohydrated and that a 1-time educational intervention would lead to improvements in hydration status. The findings from this study may help establish evidence-based fluid-replacement recommendations for this population.

METHODS

Design and Procedures

Demographic data were obtained at the start of data collection. All data were collected over 6 days of team sport-specific practices; each day consisted of prepractice and postpractice collection for the preintervention period, an educational intervention, and the postintervention period (Figure 1). Practices were similar in structure and intensity during both periods. All practices took place in an indoor, controlled, and air-conditioned facility. Pregame practices and strength and conditioning sessions were excluded from the study.

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Educational Intervention

After the preintervention period, a 1-time educational intervention was provided. This occurred in a group setting after practice on day 3 and lasted approximately 20 minutes. The women's volleyball and basketball teams were both given the same educational information; however, the sessions were conducted separately because their practice times differed. The educational intervention consisted of a presentation to the entire team containing information regarding the importance of hydration, negative effects of dehydration, and how to prevent dehydration. The information was based on the recommendations of the National Athletic Trainers' Association,¹ American College of Sports Medicine,⁶ and American Dietetic Association,⁷ which were the most current guidelines at the time of the study. Each participant was also given an summary of her own hydration status (Figure 2) from the control period, a copy of the urine color chart, and a National Collegiate Athletic Association flyer on performance hydration. The presentation included general recommendations for increasing or decreasing fluid intake based on their hydration summaries but no individualized feedback. Each person received an individual summary of hydration status with her prepractice and postpractice Usg and Ucol, as well as her average weight change during practice (pounds) and as a percentage of BM loss, average amount of fluid consumed (ounces), and average sweat losses during the preintervention practices.

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RESULTS

The following analyses involved all 25 participants. Means and SDs for all dependent variables during the preintervention and post intervention periods are provided in Table 1. A decrease in prepractice Ucol (P = .027) and an increase in HAQ score (P = .001) were present after a 1-time educational intervention. No differences were found for prepractice Usg (P = .979), postpractice Usg (P = .980), postpractice Ucol (P = .095), BM change (P = .068), fluid intake (P = .665), sweat rate (P = .894), or fluid-replacement percentage (P = .180) after the intervention.

Table 1 Hydration Status, Fluid Intake, and Hydration Knowledge Before and After the Educational Intervention (Mean ± SD)

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Prepractice to postpractice measures of Usg (P< .001, P = .001) and Ucol (P = .001, P< .001) increased in the preintervention and postintervention periods, respectively.

Means and SDs for all dependent variables by sport are shown in Table 2. No interaction was found between time period (preintervention and postintervention) and sport. Differences were demonstrated between sports for BM change (P < .001): basketball players experienced greater BM losses than volleyball players. Basketball players also displayed higher sweat rates (P = .001) and lower fluid-replacement percentages (P = .008) than volleyball players. No differences were present between sports for prepractice Usg (P = .353), postpractice Usg (P = .063), prepractice Ucol (P = .871), postpractice Ucol (P = .761), fluid intake (P = .719), or HAQ score (P = .134).

Table 2 Assessing Hydration Status, Fluid Intake, and Hydration Knowledge By Sport Before and After the Educational Intervention (Mean ± SD)

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No significant correlations occurred between HAQ scores and indices of hydration status (Usg, Ucol, %BM change) or fluid intake (P values > .05). Strong positive correlations were noted between prepractice Usg and prepractice Ucol during the preintervention (r = 0.844, P< .001) and postintervention (r = 0.930, P< .001) periods. Strong positive correlations were also evident between postpractice Usg and postpractice Ucol during the preintervention (r = 0.719, P< .001) and postintervention (r = 0.791, P< .001) periods. A weak positive correlation (r = 0.410, P = .042) was present between %BM change and fluid intake during the control period.

DISCUSSION

Our purpose was to determine whether a 1-time educational intervention improved the hydration status and fluid-intake practices of collegiate female indoor volleyball and basketball players. Based on our results, these collegiate female indoor athletes appeared to have proper hydration knowledge and hydration habits to keep themselves euhydrated before, during, and after practices. Many previous researchers have focused on prepractice and pregame hydration levels because prepractice euhydration is a vital component of any athlete's hydration status. Beginning exercise in a hypohydrated state can predispose athletes to further dehydration,²⁶ which can negatively affect both their performance and physiological function.¹⁵ Magal et al¹² and Thigpen et al²⁷ found that at least half of collegiate basketball athletes began sport participation in a less than euhydrated state. Other investigators^8–14 observed this was also true among athletes at different levels and in different sports. During our preintervention period, 28% of participants arrived at practice in a hypohydrated state (Usg ≥ 1.020 and Ucol ≥ 4), and 44% ended practice in a hypohydrated state. This trend was stronger among the basketball athletes: 40% were hypohydrated before practice, compared with only 20% of volleyball participants. After practices, 60% of basketball athletes were hypohydrated versus only 33% of volleyball athletes. Thus, mild hypohydration may be more prevalent among certain female athletes, specifically basketball players.

Despite these percentages, on average, our female volleyball and basketball athletes began practices in a euhydrated state (Usg < 1.020 and Ucol ≤ 3) and ended practice in a euhydrated state. However, variability among participants was evident in prepractice Usg, Ucol, and %BM change, indicating that variability among female athletes can be quite common in a field setting and should be considered. It is important to acknowledge that in the field setting, outside factors can and will affect an individual's hydration status and to use various methods of hydration assessment.¹ Although no criterion standard exists for hydration assessment, using urinary hydration markers along with BM changes can give the clinician a better indication of the athlete's hydration status.^1,28,29 Therefore, clinicians should use individualized hydration measures and responses to educate athletes about the importance of hydration before, during, and after exercise.

Our hypothesis that a 1-time educational intervention would improve overall hydration status and fluid-intake practices was partially supported because a decrease occurred in prepractice Ucol during the postintervention period. Previous researchers^9,17,23 demonstrated that a Ucol chart may be an effective educational tool because athletes are able to judge their hydration level by comparing their Ucol with the chart, allowing them to adjust their behaviors to improve their Ucol. Although Ucol may be affected by certain vitamins or supplements, it is a valuable tool that can be used effectively by many, particularly in combination with BM loss. Urine color is a clinically applicable measure that can be assessed in a matter of seconds in the field, which makes these findings noteworthy. In addition, HAQ scores were higher after the educational intervention, which indicates an increase in the participants' hydration knowledge. Despite this, postpractice Ucol, prepractice Usg, postpractice Usg, %BM change, and fluid intake did not improve. Thus, even though their hydration knowledge increased, the participants did not drastically change their hydration habits, probably because they had good initial knowledge of hydration, as indicated by a 90% HAQ score during the preintervention period. These results contrast with those of earlier investigators who observed that collegiate athletes lacked proper hydration knowledge. Sobana and Many²⁴ and Torres-McGehee et al³⁰ reported knowledge scores of <55% and Nichols et al³¹ noted an average of 81.7%. The former also demonstrated a significant positive correlation among knowledge, attitude, and behavior, which could suggest that the more knowledge athletes have, the better their hydration practices and status will be. To examine this possibility further, Decher et al¹⁶ incorporated hydration-status assessment when studying the relationship between hydration knowledge and behaviors in youth athletes. Their participants were mildly to severely dehydrated, even though they demonstrated a good knowledge of hydration. Similarly, we identified no significant correlation between hydration knowledge and indices of hydration (Usg, Ucol, %BM loss) and fluid intake. No previous researchers have assessed hydration knowledge in combination with specific measures of hydration status in collegiate female indoor-sport athletes, especially in volleyball and basketball. However, past results from collegiate outdoor-sport athletes displayed inconsistencies between hydration knowledge and hydration behaviors.^30,31

A notable unexpected finding in our study was that multiple individuals were drinking more fluids than necessary and gaining weight during practices. Hyperhydration can lead to EAH, which is defined as an abnormally low serum or plasma sodium concentration (typically <135 mmol/L).³² This is often caused by excessive fluid intake compared with sweat losses and can lead to serious symptoms and even death.³² Athletes who drink excessively during exercise could be at risk for EAH. In addition, female athletes have a higher likelihood of developing EAH.⁶ This could indicate a risk of hyponatremia in this population, specifically volleyball athletes, because multiple participants gained weight during practices.

During the educational intervention, participants were given a written summary of their hydration measures (ie, Ucol and Usg) along with average BM changes and sweat rates. During the control period, no single athlete had a 3-day mean BM loss of >2%. The intervention included general recommendations about how participants should increase or decrease their fluid intake based on the measures in their hydration summaries. Three basketball athletes and 2 volleyball athletes who began the study displaying less than optimal hydration markers during the control period showed overall improvement in prepractice and postpractice hydration measures after the intervention. Six individuals gained weight during the control period; although the educational session included information about avoiding hyperhydration, their behaviors did not change, and weight gain continued in the ensuing practices. It is important to recognize, though, that we did not assess the participants' blood sodium levels. Therefore, whether they were hyponatremic at any point during the study is unknown. Furthermore, although certain athletes appeared to be hyperhydrating, some arrived at practice in a hypohydrated state; hence, consuming excessive fluids may have been necessary simply to regain the euhydrated state. Thus, using various hydration methods in combination is preferred over any single hydration measure.¹ These trends were not as prevalent in basketball players, given that most lost weight during practices.

Consistent with previous authors,^11,20 we showed that our athletes were able to replace enough fluids to prevent significant dehydration, although mild dehydration was still seen occasionally. The lack of improvement in BM changes after the intervention was likely due to the fact that many participants achieved adequate hydration before the intervention. Individuals still experiencing ≥2% BM loss were perhaps not being given enough opportunities to drink water during practices or choosing not to drink enough when given these opportunities. Although it is not unusual for an athlete to experience a BM loss during practice, it is important to acknowledge that losses >2% caused performance decrements in high-performance athletes, such as collegiate players.¹

Differences in BM changes were present between sports throughout the study (Table 2). These likely reflected increased sweat rates and decreased fluid replacement in basketball versus volleyball athletes. The inherent differences between these sports (which we did not measure) might have also affected the sweat losses. On average, basketball athletes lost 0.7% of their BM during all practices (preintervention and postintervention), whereas volleyball athletes lost only 0.2%. This loss is not concerning for basketball players: our findings are consistent with the BM losses of ≤2% observed in collegiate and professional basketball athletes during practices and games.^22,27 The single investigation⁹ of volleyball athletes was conducted on youth, who demonstrated a BM loss of 0.4% during control and 0.5% after an educational intervention, which was slightly higher than our result (0.2% loss preintervention and postintervention).

Overall, it was clear that not all of our participants needed to improve their hydration status. Those who experienced prepractice hypohydration seemed to benefit the most from the educational intervention because they decreased their Usg and Ucol during the postintervention period. This indicates that a 1-time educational intervention may be useful for individuals who need to improve their hydration status. Earlier investigations of hydration education produced conflicting outcomes. Kavouras et al²³ determined that youth athletes displayed changes in their hydration behaviors after receiving a 1-time lecture on hydration. In addition, Sobana and Many²⁴ assessed the effects of education in collegiate athletes (though not outdoor-sport athletes) and identified improvements in fluid-intake behaviors, as well as knowledge and attitudes on hydration. Our conclusions agree with those of Cleary et al⁹ in that education alone was not enough to significantly improve indices of hydration status and fluid intake. Instead, prescribing adequate amounts of fluid specific to their sweat losses was successful in athletes.⁹ Contrary to our findings, the participants in various similar studies^9,23,24 were hypohydrated before the intervention, indicating a significant need for improvement.

CONCLUSIONS

These female collegiate indoor-sport athletes were generally well hydrated before, during, and after volleyball and basketball practices. Overall, they began the study with good hydration knowledge, which improved after a 1-time educational intervention. However, not all measures of hydration status improved because many participants were euhydrated before the intervention, as indicated by their urinary markers. Some individuals did experience hypohydration and benefited from hydration education by improving their hydration status. Others needed hydration education to ensure that they were not overhydrating and putting themselves at risk for hyponatremia. Overall, ATs and coaches should pay particular attention to individualizing the needs of their athletes to improve hydration in those who are hypohydrated and decrease hyperhydration in those whose fluid intake during activity is too high. Athletes who are unable to judge their fluid needs should be identified and educated on strategies for improvement.