Stretching is a very individual thing. Genetically and physiologically, we have different tissue types that make us up, that mean some people are naturally more flexible or 'stretchy' for want of a better word than others. Often it can be a case of trial and error during training sessions that determines whether you are someone that performs better following a stretching session, or recovers better by stretching after. Here are some general guidelines from recent studies on the effects of stretching:
1. Stretching at 80% of your maximum range of motion significantly decreases tension in the muscles being stretched, whereas stretching at full range often makes the muscle contract
2. Initial stretches at slow speeds are beneficial as they cause less resistance in the stretched muscle
3. The most economical time to hold a stretch is between 20 to 30 seconds. Anything less than doesn't seem to give any change in muscle length, anything longer doesn't seem to show extra benefit.
4. The greatest reduction in muscle tension when stretching takes place during the first stretch. The ideal number of repetitions to stretch is not currently known. So make sure the first one is an effective one!
5. If you already have a sufficient range of motion for the activities that you do in a sport, then the need to stretch beforehand is not always essential. In activities that require a greater range of motion eg. Ballet and karate, participants should perform some pre-stretching to achieve that required movement range.
6. Target your pre-stretching to the muscle groups known to be at risk for a particular sport eg. Hamstring strains in soccer, rotator cuff strains in tennis
7. There is evidence that stretching before an exercise session reduces the incidence of muscle strains, but not the incidence of overuse injuries.
8. Stretching after 'warm-up' is likely to be better than stretching when cold, as it seems to offer less resistance to stretch in a muscle.
If you're not sure whether you are someone that needs to stretch or not, get some professional advice from your physiotherapist, trainer or coach. Just remember what I said at the beginning, it can be a very individual thing depending on your body type, age and the exercise you are about to participate in, so make sure you're properly assessed before any recommendations are made.
References:
Decoster, L.C., Cleland, J., Altieri, C., Russell, P. The effects of hamstring stretching on range of motion: a systematic literature review. Journal of Orthopaedic & Sports Physical Therapy 2005: 35 (6):377-387
McHugh, P., Cosgrove, C.H. To stretch or not to stretch: the role of stretching in injury prevention and performance. Scandinavian Journal of Medicine and Science in Sports. 2010: 20: 169-181
McNair, P. Acute responses to stretches with isokinetic dynamometers. SportEX Medicine 2007: 34 (Oct):6-9
