Carla Casadei participated in the 2025 London Marathon and has now shared three mistakes she made as a first-time marathon runner, which made the race less enjoyable, to help others avoid the same pitfalls.
Record-Breaking Event
The London Marathon is one of the most popular marathon events globally, with thousands travelling to the historic city to take part. The 2025 TCS London Marathon set a new world record for the largest number of finishers in a marathon, with 56,640 people completing the race. This surpassed the previous record of 55,646 set by the 2024 TCS New York City Marathon. With over 1,000,000 people entering the ballot for the 2026 race, another record may be on the horizon.
Mistakes to Avoid
With these impressive numbers, many new marathon runners will be participating on Sunday, 26 April. To help, one woman who ran the London Marathon for the first time in 2025 has shared three mistakes she made during her run, aiming to prevent others from repeating them.
Taking to TikTok, London-based Carla Casadei, founder of Casadei Foods, revealed the mistakes she claimed others can prevent. "I survived my first marathon, but I made so many mistakes," she admitted in her video.
1. Wearing a Running Vest
"The first one, it was this vest," Carla said, showing the running vest she wore over her T-shirt. She explained that she trained with the vest and never had issues. However, because it was warm during the marathon, water was sprayed over runners, and she also poured water on herself to cool down. This extra water made the vest heavier. "This was weighing like five kilos," she said. "It was so heavy." Instead, she recommends using a belt to hold belongings, which won't become heavy when wet.
2. Wearing a Running Belt
"And these little belts," Carla continued, putting on a belt that held her marathon bib. "Don't even bother." She explained that the belt starts to spin while running, moving the bib from front to side or back. She recommends attaching the bib with pins in the traditional way to avoid issues.
3. Not Using Gels
"But I think, the worst mistake of it all, don't laugh, I didn't want to use gels," Carla admitted. Runners typically consume energy gels to replenish glycogen stores during long runs over 90 minutes, maintain high-intensity performance, prevent severe fatigue, and maintain blood sugar levels. Carla wanted a "healthier" alternative. "So there was me and my little dates," she shared, showing a clip of her chewing a fresh date during the marathon. Because of this, she almost fainted, noting there is a reason gels are popular. "On marathon day, just stick to the basics, have your gels, take one every 5k after every 10k, just the bare minimum, because what you need most is to be free so you can run at your best," she recommended.
