Active recovery comes in a number of different forms, and will depend in part on what sport of activity you practice.
For some athletes, active recovery means a gentle version of their regular exercise - for example, many runners who are training for a marathon will take a short, gentle run the day after a long run, or end a hard interval workout by jogging gently for ten minutes.
However, the experience of triathletes, who pack hundreds of miles per week into their schedules, suggests that doing other types of workouts is more effective and can reduce the strain from repeat workouts, particularly for runners.
Triathletes typically use easy bike rides or gentle swims as active recovery workouts on alternate days. You get all the benefits of using the muscles and clearing out the lactic acid without repeating the workout that got you sore in the first place.
Interestingly, research has recently been published which supports this view, suggesting that many runners could actually improve their race performance by reducing their mileage and using cycling as their active recovery workouts in between the tough sessions (i.e. the long runs, intervals, fartlek, etc).
Indeed, whether you are a runner, cyclists, or swimmer, there are activities you can do that will actually enhance your performance when you return to your chosen sport: