Are there any concerns or considerations?
Validity of cramping research models to real-world sporting scenarios
The vast majority of research on TRP channel agonists is conducted in a laboratory environment, using an electrically stimulated cramping model in isolated muscles or small muscle groups to measure the “threshold frequency” for cramping – that is, how easily a muscle cramps in response to electrical stimulation. Whilst the threshold frequency appears related to an athlete’s real-world susceptibility to cramping, the results of these laboratory studies have yet to be replicated in a real-world sporting context.
Unnecessary expense and lack of scientific consensus on prescription
There is currently no consensus on the optimal dose of TRP channel agonists, whether some (e.g. vinegar) are more effective than others (e.g. cinnamon), whether combining multiple TRP channel agonists provides an additive or synergistic effect, the optimal timing of ingestion, and whether mouth rinsing is equivalent to swallowing the supplement.
Tolerance of extremely pungent flavours
TRP channel agonists are, by their very nature, strong and pungent flavours, which may be particularly overwhelming during exercise in hot environments. Athletes are strongly advised to always try these products in training that simulates race conditions (i.e. exercise intensity and climate as similar as possible) before attempting to use them in a race scenario.
Gastrointestinal disturbance from ingestion of highly concentration sodium solutions
Pickle juice products in particular are extremely high in sodium, increasing the risk of gastrointestinal discomfort, nausea and/or vomiting. However, research suggests that in the small quantities consumed (~50-80 mL, or around 500-900 mg sodium at a time), there is unlikely to be any observable change in plasma sodium or osmolality5, or gastrointestinal symptoms.
Lack of understanding on the causes of EAMC and thus most appropriate interventions
Exercise Associated Muscle Cramping is poorly understood due to the difficult nature of studying the phenomenon. However, current consensus suggests that EAMC is likely a syndrome, with multiple and diverse risk factors increasing an individual’s susceptibility to cramping6, which is the ultimate outcome. Unlike other syndromes that occur in athletes (e.g. exercise induced gastrointestinal syndrome), currently there is no clear mechanistic pathway to explain the link from risk factors to cramping outcomes, and therefore treatments are generally not targeted towards a specific causal pathway. Because of this, it is not known if TRP channel agonists will be effective for all athletes who experience EAMC, or whether it is only useful in athletes whose cramping has a more specific causal pathway.