Electrolyte and plasma responses after pickle juice, mustard, and deionized water ingestion in dehydrated humans

Context: Some athletes ingest pickle juice (PJ) or mustard to treat exercise-associated muscle cramps (EAMCs). Clinicians warn against this because they are concerned it will exacerbate exercise-induced hypertonicity or cause hyperkalemia. Few researchers have examined plasma responses after PJ or mustard ingestion in dehydrated, exercised individuals. Objective: To determine if ingesting PJ, mustard, or deionized water (DIW) while hypohydrated affects plasma sodium (Na⁺) concentration ([Na⁺_p), plasma potassium (K₊) concentration ([K⁺]_p), plasma osmolality (OSM_p), or percentage changes in plasma volume or Na⁺ content. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: A total of 9 physically active, nonacclimated individuals (age = 25 ± 2 years, height = 175.5 ± 9.0 cm, mass = 78.6 ± 13.8 kg). Intervention(s): Participants exercised vigorously for 2 hours (temperature = 37°C ± 1°C, relative humidity = 24% ± 4%). After a 30-minute rest, a baseline blood sample was collected, and they ingested 1 mL/kg body mass of PJ or DIW. For the mustard trial, participants ingested a mass of mustard containing a similar amount of Na⁺ as for the PJ trial. Postingestion blood samples were collected at 5, 15, 30, and 60 minutes. Main Outcome Measure(s): The dependent variables were [Na ⁺]_p, [K⁺]_p, OSM_p, and percentage change in plasma Na⁺ content and plasma volume. Results: Participants became 2.9% ± 0.6% hypohydrated and lost 96.8 ± 27.1 mmol (conventional unit = 96.8 ± 27.1 mEq) of Na⁺, 8.4 ± 2 mmol (conventional unit = 8.4 ± 2 mEq) of K⁺, and 2.03 ± 0.44 L of fluid due to exercise-induced sweating. They ingested approximately 79 mL of PJ or DIW or 135.24 ± 22.8 g of mustard. Despite ingesting approximately 1.5 g of Na⁺ in the PJ and mustard trials, no changes occurred within 60 minutes postingestion for [Na⁺] _p, [K⁺]_p, OSM_p, or percentage changes in plasma volume or Na⁺ content (P > .05). Conclusions: Ingesting a small bolus of PJ or large mass of mustard after dehydration did not exacerbate exercise-induced hypertonicity or cause hyperkalemia. Consuming small volumes of PJ or mustard did not fully replenish electrolytes and fluid losses. Additional research on plasma responses pre-ingestion and postingestion to these treatments in individuals experiencing acute EAMCs is needed.