Is a warm up really necessary or can we just crack on ?
OK, hands up, how many of you runners honestly do a proper warm up before you go for a run ? I'm willing to bet most just pull on the trainers, start off with a gentle jog and then break into a full run after a couple of minutes before trotting back home for a shower and a cuppa after your 5km. It's a pain to have to squeeze in a warm up and stretch routine especially when you're pushed for time and need to get to work in time. But is this doing the body no favours ? Should you always include a warm up routine into your runs ?
Now my own personal opinion is that really it depends on what sort of running or exercise you are going to be doing, The majority of distance runners injuries are overuse or overload injuries, usually as a result of doing too much or increasing loads too quickly. A warm up isn't going to make a great deal of difference in this scenario. These problems occur when the body isn't conditioned ( fit enough ) to tolerate the work of the run - it's more about load management and building a good training programme.
However, sports involving more explosive, powerul acceleration type actions definitely benefit from a good warm up to prevent muscle and ligament damage. There is a wealth of good evidence that team and field sports like football, tennis, basketball, rugby, hockey and sprinting all benefit from a warm up tailored to their individual sports demands.
Interval running therefore kind of sits between these two disciplines as there are elements of distance and explosive acceleration in this kind of training. In this instance I would suggest a warm up of some description to minimise the chances of injury. This could be something as simple as a gentle jog for 5 -10 mins and then another 5-10 mins of high knee marches, leg swings, crossover swings, jumping and plyometric or springing type of exercises. Plyometric or bouncing type of activity shows some evidence of improving running economy, encouraging energy to be stored in the tendons and ligaments so that they act like a spring during a run.
Stretching
There is very little good credible evidence that stretching healthy tissues prior to exercise prevents any kind of injury - indeed in the case of prolonged static stretches we know it can be positively detrimental, briefly lowering power output of the muscles. A better method of stretching is static holding ( isometric ) type exercises which progressively loads the tissues and can help reduce pain in already injured tendons. Wall squats, static squats, planking etc are all static forms of exercise, where th eposition is held for a period of time.
In general warm up is useful for prepping the body for explosive activities or those that involve cutting motions or rapid accelaration / deceleration. When looking to develop a warm up for yourself, think about the actions that your body is about to do and incorporate them into your warm up alongside some plyometric type exercise. If you're doing a gentle 3k then just take it easy for the first kilometre of your run and a nice hot shower afterwards.