Comparison of Two Reminder Interventions to Achieve Adequate Water Intake and Hydration in Women: A Pilot Study

Introduction: This pilot study examined the effectiveness of two different 5-week reminder interventions to achieve adequate water intake and hydration in women as well as the effects of body composition and self-efficacy on hydration. Methods: Twenty-two apparently healthy adult women were randomly assigned to the 64 oz. motivational water bottle group (n = 11), or the water reminder – daily tracker app group (n = 11). Body composition, predicted VO2max, and self-efficacy were assessed at baseline, post 5-week intervention, and after a 30-day follow-up period. Urine markers (color, specific gravity, and pH) were reported at baseline, weekly throughout the 5-week intervention, and the last 3 days of the 30-day follow-up period. During the interventions, participants self-reported daily step count, resting heart rate, water intake, and symptoms of dehydration. Results: Both 5-week reminder interventions successfully increased water intake by an average of 29% with a mean daily consumption of 72.05 + 18.75 ounces, meeting recommendations. Based on regression analysis, self-efficacy predicted daily water intake at the end of the 5-week intervention (p = 0.03). Urine markers of hydration classified several participants as dehydrated at the end of 5 weeks. In addition, there was a significant inverse relationship between BMI and Ucol at baseline (p = 0.05), week 5 (p = 0.05), and follow-up (p = 0.04), indicating that women with a higher BMI were more dehydrated. In hydrated participants, memory and ability to concentrate significantly improved (p = 0.019). Results indicated there were no significant differences in water intake and hydration between the two groups at baseline, week 5, and follow-up. Conclusions: Both 5-week interventions successfully increased water intake. However, based on urine markers of hydration women may be more prone to involuntary, chronic dehydration due to a higher body fat percentage.