Ketchup goes perfectly with french fries, chicken tenders and meatloaf. But what about a 5K?

Heinz has a new ad showing runners using packets of ketchup to power up. With 3 grams of carbohydrates per packet, Heinz says they can work much like energy gels and other similar products favored by runners.

“Runners everywhere are using Heinz ketchup packets on their runs,” Heinz said in the video. 

But is this a realistic approach? USA TODAY spoke with a dietician who has her doubts.

Watch:Runner's emotional reaction to a memorable finish at the New York Marathon

How much energy do runners need?

Endurance athletes typically require 30 to 60 grams of carbohydrates per hour of exercise, according to a Cleveland Clinic report in 2020.

“Runners, swimmers, cyclists or anyone who exercises for more than 60 minutes needs to adequately fuel their body for the best workout,” dietitian Katherine Patton said in the report. “This is important because while you exercise, your body draws on carbohydrates stored in your muscles. However, the available amount is limited.”

Patton said that consuming carbs during exercise improves metabolic response and prevents glycogen depletion. She recommends endurance athletes to take gel packs containing  23 to 27 grams of carbs. 

One packet of GU Energy Gel, for instance, has 21 carbs.

Heinz makes packet-shaped routes for runners 

As part of their running campaign, Heinz released three map routes runners can follow to catch up on their ketchup intake. The food manufacturer crafted the trails to be the "keystone" shape of a Heinz ketchup packet. 

New York, San Francisco and Toronto are the North American cities with these routes that can be found online. The brand said they will soon drop new routes in Chicago, Pittsburgh and Vancouver.

Amy Stephens, a sports dietitian for New York University’s track and field team and a runner herself, said that there are a few logistical challenges to using ketchup as a fuel source

For one, a runner would have to consume 15 to 30 packets for a long-distance run like a half marathon, which is 13.1 miles. 

Stephen said she would struggle carrying and having to open that many ketchup packets during a run and that it would be hard to track how many she's had while focusing on her pace.

The tomato concentrate or puree found in each packet is also highly acidic, meaning runners with gastrointestinal issues could experience additional issues.

Plus, at 95 milligrams per packet, "it’s way too much sodium," she told USA TODAY on Friday. "Most people don't need that much per hour of a race. It can actually cause a headache. Taking excessive sodium can make you really thirsty and then you're ending up having to just find water.” 

Do you put ketchup in the fridge?Heinz sparks debate on social media

Other alternatives to energy gels and ketchup

Honey packets are a healthier alternative for a running source than ketchup, Stephen said. It contains more carbs than ketchup (17 grams versus 4.5 per tablespoon), so carrying and consuming it is simpler.

If a runner is stopping at a fast-food place they could also order a lemonade, iced tea or one or two salt packets, which Stephen said are healthier options.