Creatine + Beta-Alanine: The Stack Bonus Researchers Couldn't Find
The creatine plus beta-alanine stack is marketed as a performance power couple, but a new network meta-analysis of 52 randomized trials found no synergy between them. Creatine alone significantly improved sprint, jump, repeated-sprint and upper-body endurance outcomes versus placebo. Beta-alanine's effects were non-significant or context-specific, and the combo added nothing beyond creatine. Here's what the study did, where it falls short, and what it means for your supplement budget.
Low-Dose Caffeine Coffee Gave Elite Fighters Zero Sprint Boost
Think your pre-workout coffee is supercharging your sprints? A new randomized, double-blind crossover trial in 15 national-level combat athletes found no performance benefit from caffeine doses of 1.5 and 3 mg/kg, about 100 and 200 mg for a 68 kg athlete. Peak power, mean power, fatigue index and even estimated energy system contributions did not differ from decaf. But this is a small null result, not proof that caffeine fails, and most positive studies use capsules at 3–6 mg/kg. Here is the dose math, the caveats and what to actually do before your next hard session.
This Carnitine Form Lifted Sprint Power Up to 15% and Cut Lactate
A 2009 crossover study found that a single 4.5 g dose of glycine propionyl-L-carnitine (GPLC) lifted peak and mean sprint power by 2.6% to 15% across five all-out cycling bouts. Blood lactate was also 16.2% lower 14 minutes after exercise. But the "15%" is the top of a range, not an average, and the study involved just 24 men in one lab. This article breaks down how GPLC differs from regular L-carnitine and ALCAR, where the nitric oxide theory fits, and who might actually benefit. It also covers dose, timing and the limits of the evidence.