Active Lives Online - Sport England's tool for measuring sport and activity across the country.
Adventure Activities Licensing- part of the Health & Safety Executive (HSE) website for activities outdoors
ExRx.net (Exercise Prescription on the Internet) is a free resource for the exercise professional, coach, or fitness enthusiast featuring comprehensive Exercise Library (>1600 exercises), fitness assessment calculators, and reference articles
Sport Science - peer-reviewed journal and site for sport research
WADA - Contains link to the full report issued on the 9th November 2015