A pair of Solihull fitness brands feature in an annual countdown of the UK's private companies with the fastest-growing sales.

Online clothing firm Gymshark and nutrition manufacturer Grenade are both ranked in the 22nd Sunday Times Virgin Atlantic Fast Track 100 league table.

The yearly report lists the 100 privately owned UK companies with the fastest-growing sales over the latest three financial years.

Gymshark was started by Ben Francis in his parents' garage when he was just 19 and its clothing lines have become a must-have for the Instagram generation as the company has tapped into the power of social media to boost its market presence.

In April, it relocated from Worcestershire to a brand new head office in Solihull which will give it the space to more than double its current payroll of 200 staff.

Gymshark's head office in Solihull
Gymshark's head office in Solihull

Mr Francis was listed in BirminghamLive's 30 Under 30 feature earlier this year which profiled 30 of the city's most enterprising and inspiring young people.

It is the third time Gymshark has featured in the list, with sales climbing by 128 per cent to £103 million, placing it in 12th position.

Grenade is run by husband and wife team Alan and Juliet Barratt and sells sports nutrition products such as energy bars, powders and drinks as well as branded clothing.

The company has undergone two private equity deals since the pair launched the business in 2010.

It appears for a fifth time with sales of £33.8 million and growth of 71 per cent, placing it 47th.

Grenade co-founders Alan and Juliet Barratt
Grenade co-founders Alan and Juliet Barratt

They are among eight West Midlands companies and 12 in total from across the Midlands to feature in the 2018 countdown, including six new entrants.

Their sales have grown by an average of 88 per cent a year over three years to a total of £434 million and they collectively employ more than 1,300 people.

Among the other West Midlands businesses to feature are Burton-based clinical trials supplier Midwinter Solutions, with sales growth of 233 per cent to £61.8 million, placing it in the UK top three.

Its final position will be revealed in the Sunday Times this weekend.

Birmingham-based waste collection services firm Clearabee (78 per cent; £9 million) and advertising spacer leaser Elonex Group (52 per cent; £6.7 million) are also placed in 33rd and 75th positions respectively.

Companies from elsewhere in the UK to feature include burger chain Five Guys, beauty products retailer Charlotte Tilbury Beauty and brewer BrewDog.