Do you stretch before exercise, be it gym work, running or anything else? Have you ever wondered why you do it? Most people believe that it helps to reduce the likelihood of injury as well as improve performance.
However there is no research evidence that supports this belief. One anecdotal argument to support this is asking why would taking muscles beyond their normal resting length for 30 seconds confer any benefit when in fact you are creating micro tears in the muscle, (read minor damage) and thus minor inflammation. A damaged inflamed muscle is not going to help.
By comparison an active warm up has been reported to improve running performance, although the injury risk benefit for runners is still unclear.
Static stretching does not necessarily adversely affect performance and can still be done before exercise but it is worth noting that the perceived benefits as mentioned above are not there. However they can improve joint range of motion and may assist a runner to relax after running. When to stretch is also up for debate but the general thinking is to wait for the muscular system to cool down, to wait until after a shower and about an hour later and then to perform the stretches. There is very little difference in the benefit of holding a stretch for 30 or 60 seconds so if you have the time hold for longer but it does not really matter after 30 seconds.
So what is an active warm-up?
In general terms it is movements that mimic the main movements of the sport being done. So for running it can be 5-10mins of fast walking or light jogging prior to or during the first part of the run. You can complete dynamic stretching drills that move the joints through full range of movement like walking lunges. You can finish by completing 3 or 4 short efforts of 100m at the pace that you intend to train.
For the benefit of general muscle and connective tissue resilience at and below the knee I have also recommended slow careful side-stepping cross overs as well as jogging backwards. Although these are not movements you might do when out for a run they introduce different twists and torsions that may help to create resilience in the muscles that control foot position including the Achilles Tendon. AS they are integral in many field sports like hockey, football and rugby these should form an essential part of the warm up.
For other sports the active warm up should consist of running drills that mimic the sorts of running performed during the activity as well as neuromuscular warm up to warm-up the ‘coordination’ skills required. In the gym use bands and light weights for each of the exercises that are going to be done before loading up with the intended resistance for that particular session.
Although not fully understood injury can come from neuromuscular fatigue, overreaching when tired and training too much without proper recovery. Bear all of these in mind when you are exercising. Also listen to your system. if you feel tired at the start of a 10km run then do less. If you do not feel energised to lift heavier weights then do a light circuit or yoga or a stretch/flow session. Rest is as important as exercise.