Ad Libitum Hypertonic Saline, and Deionized Water Ingestion

Ad Libitum Fluid Intake and Plasma Responses Following Pickle Juice,
Hypertonic Saline, and Deionized Water Ingestion
NDSU Athletic Training
Scott T. Allen, LAT, ATC*, Kevin C. Miller, PhD, LAT, ATC*, Jay M. Albrecht, PhD, LAT, ATC, HFS*,
Julie A. Garden-Robinson, PhD, LRD*, Elizabeth H. Blodgett Salafia, PhD†
*North Dakota State University, Departments of Health Nutrition and Exercise Sciences
and Human Development and Family Science†, Fargo ND, USA
Abstract
Context:Adding sodium (Na+) to drinks improves rehydration and ad libitum
fluid consumption. Clinicians (~25%) use pickle juice (PJ) to treat cramping.
Scientists warn against PJ ingestion fearing it will cause rapid plasma volume
restoration, thereby decreasing thirst and delaying rehydration. PJ drinking
guidelines have been developed but never tested. Objective:Determine if
drinking small volumes of PJ, hypertonic saline (HS), or deionized water (DIW)
affects ad libitum DIW ingestion, plasma variables, or perceptual indicators.
Design:3x6 factorial, crossover. Setting:Laboratory. Patients or Other
Participants:Fifteen, euhydrated (urine specific gravity≤1.01) men (age=22±2y,
ht=178.47±6.26cm, mass=82.97±8.36kg). Interventions:Subjects completed
three testing days. After 30-minutes rest, a blood sample was collected.
Subjects completed 60 minutes of hard exercise (36±2°C, 16±1% humidity).
Post-exercise, they rested 30 minutes, had a blood sample collected, rated
thirst, fullness, and nausea, and ingested 83±8mL of PJ, HS, or DIW. Subjects
rated drink palatability (100-mm visual analog scale) and were allowed to drink
DIW ad libitum for 60 minutes. Blood samples and thirst, fullness, and nausea
ratings (100-mm visual analog scales) were collected at 15, 30, 45, and 60
minutes post-treatment drink ingestion. Main Outcome Measures:Ad libitum
DIW volume, percent change in plasma volume, plasma osmolality (OSMp,)
plasma sodium concentration ([Na+]p), and thirst, fullness, nausea, and
palatability ratings. Results:Subjects consumed more DIW ad libitum following
HS (708.03±371.03mL) than DIW (532.99±337.14mL, P<0.05). Ad libitum DIW
ingested following PJ (700.35±366.15mL) was similar to HS and DIW (P>0.05).
[Na+]p, OSMp, percent change in plasma volume, thirst, fullness and nausea did
not differ between treatment drinks over time (P>0.05). DIW (73±14mm) was
more palatable than HS (17±13mm) and PJ (26±16mm, P<0.05).
Conclusions:The rationale behind PJ drinking guidelines is questionable.
Subjects drink more, not less, after PJ ingestion, and plasma variables and
perceptual indicators are similar post-PJ and DIW ingestion. To fully rehydrate,
athletes should schedule their drinking.
Background
•  Adding sodium to drinks improves ad libitum (i.e., voluntary) fluid
intake.
•  25% (92 of 370) of athletic trainers use pickle juice to treat
muscle cramps.
•  Others fear drinking pickle juice will increase [Na+]p and OSMp
thereby decreasing thirst and the amount of fluid consumed.
Research Question
•  Does ingesting small volumes (1 mL·kg-1 body mass) of pickle
juice, hypertonic saline, or DIW immediately prior to ad libitum
DIW consumption affect ad libitum fluid volume consumed, Δ in
plasma volume, [Na+]p, or OSMp, or perceptions of thirst,
fullness, nausea, or palatability.
Research Hypotheses
•  Ad libitum fluid ingestion, changes in plasma volume, [Na+]p,
OSMp, and perceptions of thirst, fullness, and nausea will be
higher following pickle juice and hypertonic saline consumption
than DIW.
•  Palatability would be lower following pickle juice and hypertonic
saline ingestion than DIW.
Methods
Experimental Design:
• 3 x 6 factorial, crossover design.
Independent variables were drink
(pickle juice, hypertonic saline, DIW)
and time (-105 min pre-ingestion, -0.5
minutes pre-ingestion, and 15, 30, 45,
and 60 min post-ingestion).
• Dependent variables were volume of
fluid consumed ad libitum (mL), Δ in
plasma volume (% from baseline), [Na
+] (mmol·L-1), OSM (mOsm·kg-1 H O),
p
p
2
thirst (mm), nausea (mm), fullness
(mm), palatability (mm).
Results
Conclusions
•  Subjects were similarly euhydrated prior to exercise each day and became similarly
hypohydrated post-exercise (-1.95 ± 0.51%, P < 0.05).
•  DIW ingested ad libitum differed between drink
•  Hypertonic Saline = 708.03 ± 371.03 mL; Pickle Juice = 700.35 ± 366.15 mL; DIW = 532.99
± 337.14 mL (P < 0.05).
•  [Na+]p, OSMp, and Δ in plasma volume data can be found in Figure 1. Nausea, thirst, and
fullness data can be found in Figure 2.
•  Subjects preferred DIW (73 ± 14 mm) over hypertonic saline (17 ± 13 mm), and pickle juice
(26 ± 16 mm, P < 0.05). Pickle juice and hypertonic saline palatability were not different (P >
0.05).
Procedures
• 15 euhydrated, physically fit males
(age = 22 ± 2 y, ht = 178.47 ± 6.26 cm,
mass = 82.97 ± 8.36 kg) completed
testing on 3 days.
•  Drinking pickle juice will not affect perceptions of thirst postexercise. The volume of fluid consumed, not it s content, is
responsible for perceived thirst.
•  Differences in volume of fluid consumed ad libitum cannot be
attributed to differences in [Na+]p or OSMp, or Δ in plasma
volume.
•  Subjects may have drank more because of the low palatability of
pickle juice and hypertonic saline.
•  Mild nausea and fullness were reported during rehydration, but
were not exacerbated by any of the treatment drinks.
•  Our findings are in agreement with previous research examining
pickle juice and [Na+]p OSMp, and Δ in plasma volume.
• A 5 ml blood sample was collected.
Subjects exercised for 60 min (36±2°C,
16±1% humidity). A second blood
sample was collected, subjects rated
thirst, fullness, and nausea on separate
100-mm visual analog scales. They
then ingested 83 ± 8mL of a treatment
drink and rated palatability (100-mm
visual analog scale).
Clinical Significance
•  While subjects drank more fluid when hypertonic saline or pickle
juice was ingested, they were still significantly hypohydrated
after 60 minutes (1.3% hypohydrated).
•  The National Athletic Trainer s Association recommends
replacing 150% of fluid lost and diluting drinks to 0.3 to 0.7 g/L.
To comply with these recommendations, our subjects would
have needed to consume between 1000 and 2500mL of DIW.
• Subjects were allowed to drink DIW ad
libitum for 60 minutes. Blood samples
and thirst, fullness, and nausea ratings
(100-mm visual analog scales) were
collected at 15, 30, 45, and 60 minutes
post-treatment drink ingestion.
•  While pickle juice doesn t deter drinking, total body rehydration
does not occur ad libitum within 60 minutes.
•  Regardless of pickle juice ingestion or not, clinicians need to
have athletes rehydrate on a drinking schedule if they wish to
fully rehydrate athletes within 60 minutes.
• To minimize bias, subjects were not
told the purpose of the study was to
measure DIW consumed.
•  Pickle juice drinking guidelines are based on faulty rationales,
but will likely ensure more complete rehydration.
Statistical Design
• Means ± SD were calculated for all
dependent variables. Separate
repeated measures ANOVAs used for
all dependent variables. Tukey-Kramer
post hoc tests were used upon
identification of significant F-values.
• Significance was accepted when P <
0.05 (NCSS 2007, Kaysville, UT)
•  Drinking pickle juice does not negatively impact ad libitum fluid
consumption post-exercise. Subjects consumed more, not less
DIW after hypertonic saline and pickle juice than DIW.
Acknowledgments
Figure 1. OSMp (A), [Na+]p (B), and plasma
volume changes (C) pre- and post-ingestion of
drinks (Means ± SD). a = -105 min < all other
times. b = -0.5 and 15 min > 30, 45, and 60 min. c
= -105 min > all other times. d = -0.5 min < 30 and
45 min. e = 30 and 45 min > 60 min.
Figure 2. Nausea (A), thirst (B), and fullness
(C) over pre- and post-ingestion of drinks (Means
± SD). a = -0.5 min > all other times. b = 15 min >
45 and 60 min.
•  We thank NDSU s College of Human Development and
Education, NDSU s Department of Health, Nutrition, and
Exercise Sciences, and NDSU s Athletic Training Education
Program for partially funding this research.
Presented at the North Dakota Athletic Trainer s Association (NDATA) Symposium, Bismarck, ND 2012