Hydration. Not the most glamorous topic, and a tough sell to footballers fixated on the ball rather than the science. Yet it’s simple: the body is over 60% water and performance, sleep and recovery suffer if fluids aren’t topped up correctly.
The Gatorade Sports Science Institute (GSSI) has long worked with elite teams — past clients include Manchester City, Brazil and Barcelona — helping players understand their individual hydration and fueling needs to boost performance, reduce fatigue and stay off the physio table. The science is clear: inadequate fluid intake eventually hurts performance.
What the GSSI can quantify is how each player’s hydration responds to exercise and daily life. That individual data is what convinced Wrexham’s head of medical performance and sports science, Kevin Mulholland, to adopt the programme. Mulholland tells Sky Sports that testing players pre- and post-match shows who is most at risk of dehydration late in games, and allows strategies to keep them performing for 96–97 minutes — the period when many matches are decided.
I visited Wrexham’s SToK Cae Ras on a day when both the men’s and women’s first teams were undergoing a “sweat test,” a process the club runs a couple of times each season. The GSSI times these assessments to intensive training sessions that mimic match effort and resultant perspiration. The testing begins with a weight check and a urine sample to benchmark body-mass change and hydration status.
Dr Ian Rollo, principal scientist at GSSI, notes even those who have drunk water on arrival can show mild dehydration in analysis. The physical work that follows — 15 minutes on an exercise bike then pitch drills designed to recreate football’s stop-start nature — raises heart rate and sweat production. The GSSI fits a Gx sweat patch on the arm (and others on the back) that collects sweat for analysis of volume and electrolyte concentration. A tiny tube in the patch visibly fills during the session, and the collected sweat is later analysed to tailor individual recommendations.
During high-intensity sessions, GSSI typically recommends a standard Gatorade sports drink containing fluid, carbohydrates and electrolytes. For less intense days where carbs aren’t required, a Gatorade Hydration Booster supplies fluid and electrolytes without the extra carbohydrates.
Final measurements — another weigh-in and the amount drunk during the session — allow a straightforward calculation: weight change minus fluid consumed equals fluid loss. A bespoke phone app analyses the sweat patch and instantly provides how much an athlete should drink per hour of exercise to maintain hydration. My own results were surprising but underscored that sweat rates vary widely.
Rollo explains this variation: more muscular athletes and those working harder generate more metabolic heat and thus higher sweat rates. Some of the highest rates are seen in American footballers (large muscle mass, heavy kit, hot conditions), but footballers can also have saturated kits during matches. It’s not simply “good” or “bad” — it’s individual.
For Wrexham, applying that individual data is about practical gains on matchday: preventing late-game decline, reducing fatigue and lowering injury risk. Proper hydration may not attract the headlines of goals or transfers, but tailored fluid strategies could be a subtle determinant of where teams finish in the Championship and beyond.