Aug 30 (Reuters) - Fitness tracker startup Whoop said on Monday it had raised $200 million in a Series F funding led by SoftBank"s (9984.T) Vision Fund 2, valuing the company at $3.6 billion. The company said it would primarily use the new capital to invest in research and product development, international expansion and membership offerings. The funding round also included venture capital firms IVP, Cavu Ventures, Thursday Ventures and tech investment bank GP Bullhound. Founded in 2012 by Will Ahmed, Whoop offers a monthly subscription for round-the-clock health monitoring through a free fitness band it provides with the membership. Ahmed last year said customers were increasingly using its tracker technology to measure their respiratory rate, a key statistic for understanding COVID-19. The company"s tracker is the fitness band of choice for athletes including golfer Justin Thomas, Kansas City Chiefs quarterback Patrick Mahomes. Boston-based Whoop said it has raised nearly $400 million till date.