Nestlé has bought the sports hydration brand Nuun for an undisclosed sum according to reports.

Best known for their colourful tubes of electrolyte drinks tablets, Nuun have been in the cycling market for 16 years specialising in low-calorie drink supplements designed to hydrate athletes.

The deal sees private equity investment firm TSG Consumer Partners sell their stake to Nestlé Health Science, with the sale expected to be concluded by the end of the year.

"Over the past few years, our partnership with TSG has helped accelerate our mission to enhance the lives of millions of consumers who increasingly seek healthy fitness solutions," said Kevin Rutherford, CEO of Nuun.

"TSG's marketing expertise and set of resources have helped drive our expansion beyond our core fitness enthusiast market and solidify Nuun as a household name brand. We thank TSG for their support of our mission and culture and are excited to enter our next chapter of growth."

"We are incredibly proud of what we have accomplished through our partnership with Kevin, the entire team at Nuun and Dan Nordstrom, Nuun's early lead investor," said Michael Layman, Managing Director at TSG.

"Since our investment in 2017, we have collaborated with Dan to support the company's expansion into additional product categories and into new channels, which have resulted in a best-in-class portfolio of hydration offerings and significant top-line growth.

"Today, Nuun is a major force in the healthy hydration space that resonates with all types of consumers, and we are confident it will continue to thrive with the backing of Nestlé Health Science."

Nestlé Health Science is a globally managed business unit of Nestlé, offering an extensive portfolio of science-based consumer health, medical nutrition, pharmaceutical therapies, and vitamin and supplement brands.

Headquartered in Switzerland, Nestlé Health Science has more than 7,000 employees around the world, with products available in more than 160 countries.