Organisers of Brighton Half Marathon announced only compostable paper cups will be used at its water stations in a bid to reduce plastic at the event.
It is also encouraging runners to bring their own refillable bottles, and will be giving out canned water from local company Life Water at the finish line.
The Half Marathon takes place on Sunday (February 24), with the main race starting at 9.30am.
Everything you need to know about Brighton Half Marathon
Organisers of The Grand Brighton Half Marathon said: "As part of our commitment to reducing our environmental impact, we are moving away from using single-use plastics at our water stations.
"For 2019, we will be distributing water at our three water stations in fully compostable paper cups. We also encouraged runners to bring their own refillable bottles which can be topped up in race village and on course. This again will help to reduce the amount of plastic waste, as bottles can be refilled rather than discarded."
It said there will be three water stations along the 13.1 mile course, at 2.3 miles (Marine Drive), 5.6 miles (Marine Parade), and 9.2 miles (Kingsway).
Organisers added: "In addition, we are working with Life Water to give out cans of water at the end of the race, rather than using plastic bottles. All these cans are fully recyclable, and we will provide multiple recycling bins to help ensure no waste is left on the course.
"The Life Water Can is the UK’s first, zero plastic alternative to bottled water. It’s BPA free, made from recycled aluminium and has been voted Best Water Drink 2018. Every can funds clean water projects around the world as part of their mission to alleviate the World Water Crisis."
There will be recycling points on Madeira Drive for the cans and cups.
To find out more, visit: www.brightonhalfmarathon.com/preparation/hydration/