Stretching the hamstrings

In a recent post we looked at the effects of passive stretching on racing performance. In essence, we reported that if you stretch muscles passively before racing then you are likely to inhibit their performance.

Given that passive stretching is of no benefit before racing, when and how should we stretch to ensure our muscles are able to cope with the rigours of not just running but racing?

It is well-documented that passive stretching increases the range of motion (ROM) of joints and muscles, but less well documented how passive stretching should be performed. In particular the duration and intensity of the stretch.

Firstly, the intensity. It is difficult to base optimum stretching intensities on feel alone because we all have varying pain thresholds. To say, ‘do not stretch beyond the point of pain’ will mean different things to different people. However, if we are to stretch at home, without expert supervision, then some degree of intensity should be ascertained. Stretching is not always comfortable, but it should not be painful, and if soreness exists after stretching then that is almost certainly an indication that it’s been overdone.

As for duration. In the ‘runners’ bible’: Lore of Running, Tim Noakes gives sound guidance on the art of stretching. Most (although not all) of his advice is strongly backed up by more recent research.
The important points are:
Start a stretch slowly and easily to reduce the activation of the stretch reflex. The protective stretch reflex causes the affected muscles to quickly contract if they are stretched suddenly — just the action we do not want in this instance.
The stretch should last 30-90 seconds. Stretching for these longer durations allows the muscles to relax more and a greater range of motion to be attained. According to Gracie Hughes (1996), stretches performed three to nine times, 3 times a day will increase flexibility within seven to nine days.

Research by William D Bandy and Jean M Irion published in: The Effect of Time on Static Stretch on the Flexibility of the Hamstring Muscles, concluded that stretching for 30-60 seconds was more effective for increasing flexibility than stretching for 15 seconds. However, there was no significant benefit apparent for a 60-second stretch compared to a 30-second stretch.

In conclusion then, frequency and duration are key elements in an effective stretching program. If you suffer with tight muscles, and many runners do, then a disciplined stretching regime will help you to restore the flexibility you need — with emphasis on the word ‘disciplined’.