P90 Labs Science · 9 min read · Ingredients
Ask a room of collegiate soccer players what ruins their match-day fuelling more than anything else and the answer is rarely the science — it is the stomach. Nausea, sloshing, cramping, and urgent bathroom trips affect up to 30–50% of endurance athletes during hard competition, and soccer's combination of high-intensity intermittent running and halftime fuelling windows makes it unusually prone to the problem ( de Oliveira & Burini, 2014 ).
This article explains the causes of exercise-related GI distress, how formulation choices (and dual-source carbohydrates) prevent them, and how gut training makes your digestive system as fit as your legs.
What Causes the Problem
1. Splanchnic hypoperfusion. During hard exercise, the body shunts blood from the gut toward working muscle and skin. Intestinal blood flow can fall by 50% or more, reducing the gut's absorption capacity precisely when you are asking it to process fuel ( van Wijck et al., 2012 ).
2. Transporter saturation. Single-source glucose fuel saturates SGLT1 at ~60 g/h; anything beyond that accumulates in the lumen and attracts water, causing cramps. Multi-transportable carbohydrates (maltodextrin + fructose) distribute load across two transporters and demonstrably reduce stomach fullness during exercise ( Jeukendrup, 2017 ).
3. Osmolality and bulk. Hypertonic, high-sugar drinks draw water into the gut; large fluid volumes slow gastric emptying, as covered in our hydration science article.
4. Caffeine and fat. Both stimulate bowel motility and can provoke GI symptoms in sensitive athletes — another reason the P90 Gel is caffeine-free.
Formulation Fixes: The P90 Gel Approach
The P90 Gel was designed around GI tolerance: maltodextrin for low osmolality, fructose to double-transport the fuel, 18 g total carbohydrate per 30 ml tube (small volume), no caffeine, no excessive sweetness, and gentle dimagnesium malate rather than the laxative oxide forms common elsewhere. Guar gum provides the thickening that keeps the gel cohesive on swallowing without adding bulk. Manufactured in the UK under BRC Issue 9, Halal-certified, and NSF GMP standards, it is built to the same tolerance expectations as the gels used in Premier League fuel rooms.
Gut Training: The 6-Week Protocol
You can literally train your gut to absorb more carbohydrate. Just as muscles adapt to load, the intestine up-regulates SGLT1 transporter density within days to weeks of repeated carbohydrate exposure during exercise ( Jeukendrup, 2017 ). A simple protocol:
•Weeks 1–2: 30 g/h of carbohydrate in training; note any symptoms.
•Weeks 3–4: progress to 45–60 g/h; test the gel you plan to use on match day.
•Weeks 5–6: rehearse the full match-day protocol in a game-intensity session.
Never introduce a new product on match day. Tolerance is trained, not guessed.
Frequently Asked Questions
Can gut training really increase how much I can absorb?
Yes. Both animal and human data show up-regulation of intestinal transporter capacity with repeated carbohydrate exposure, and athletes who gut-train report significantly fewer GI symptoms at higher intakes ( Jeukendrup, 2017 ).
What if I still get nausea?
Check three things: (1) are you taking the gel with water; (2) is total carbohydrate at or below 60 g/h; (3) was it tested in training? If all three hold, drop the intake slightly and rebuild tolerance.
References
1.de Oliveira EP, Burini RC. Carbohydrate-dependent, exercise-induced gastrointestinal distress in athletes. Current Opinion in Clinical Nutrition & Metabolic Care. 2014;17(4):409–414. https://doi.org/10.1097/MCO.0000000000000069
2.van Wijck K, et al. Exercise-induced splanchnic hypoperfusion results in gut dysfunction in healthy men. PLoS ONE. 2011;6(12 ):e22366. https://doi.org/10.1371/journal.pone.0022366
3.Jeukendrup AE. Training the gut for athletes. Sports Medicine. 2017;47(Suppl 1 ):101–110. https://doi.org/10.1007/s40279-017-0690-6