A fitness expert has slammed Logan Paul and KSI's Prime energy drink and called it their “most profitable scam yet”. James Smith looked at the science behind hydration and claimed that despite the fact the drink is the official hydration sponsor of UFC, Bayern Munich, Arsenal and Barcelona, Paul and KSI “don’t even understand” the concept of hydration. Explaining how rehydration works, Smith said that water and sodium are key to tackling dehydration. He said: “If you’re partaking in a sport [where you] lose loads of water and loads of salt [and you] replenish with just water, over time you’re going to create a negative balance of sodium.” While Smith explained that replenishing electrolytes sodium, potassium, calcium, and magnesium, it was sodium that is the most important to replenish. He then compared Prime’s offering to other leading brands, showing that Prime only has 5mg of sodium. It did however have an impressive 700mg of potassium. Logan Paul's Most Profitable Scam Yet www.youtube.com Powerade, meanwhile, contains 168mg of sodium and 200mg of potassium. “So understanding that when we sweat we lose mostly water and salt, which one of these two, [Prime of Powerade], do you think is going to be superior when it comes to replenishing the sodium that you’re losing?” he asked. It comes after Paul and KSI’s Prime defended the levels of caffeine in its beverages after facing a backlash. Health experts previously called on the US Food and Drug Administration to investigate the energy drink company. A 12 oz can of Prime, which was founded by YouTube stars Logan Paul and KSI, contains 200mg of caffeine, equivalent to about half a dozen Coke cans or nearly two Red Bulls. Sign up to our free Indy100 weekly newsletter Have your say in our news democracy. Click the upvote icon at the top of the page to help raise this article through the indy100 rankings.