Best gym classes for runners

SpeedFlex, £30, nationwide

SpeedFlex is an innovative cardiovascular and resistance workout that’s low intensity but high impact, making it a great choice for runners. This clever bit of kit creates resistance for your workout through hydraulics and electrical impulses, eliminating eccentric forces that can increase your chance of injury. During a SpeedFlex session you accelerate through exercises with the greatest amount of force at a high speed, which leads to maximum results while minimising muscle damage. The sessions focus on developing muscular endurance, strength and balance in the legs to ensure increased running speed and endurance, ideal for anyone who wants to improve their performance and run stronger than ever.