When we run, we all 'bounce' to a certain extent. By this I mean when we push off the floor we move vertically up and down as well as horizontally. According to Dr Alex Hawkins (whose instagram page has some excellent running related information), a runner will typically leave the surface by 5-12cm and this isn't a cause for concern. A problem occurs however when excessive bouncing takes place (please view the above image for an example). You've probably noticed Tigger like runners out there on the road, and if you haven't seen them you definitely would've heard them! These athletes are moving too far vertically during each stride and are possibly creating 2 types of issues for themselves:
Decreased performance levels - by travelling too far vertically, energy is being used on up and down movement when it could be better utilised on forward momentum. After all, the primary goal of distance running is to move forwards, not up!
Increased injury risk - by falling a greater distance, this will raise the likelihood of experiencing an impact injury such as shin splints. Lower the vertical fall and the amount of force going through the joints is also decreased.
If you think you may be bouncing too much, then my advice would be to get a friend to film you either running outside or on a treadmill. Slow the footage down, then keep an eye on the vertical movement of your head as well as how far you're leaving the surface during each stride. The photo above shows far less bounce and this should be the target.
Another thing you could do is listen to your foot strike. If it's loud then you may well be landing with excessive force due to falling too far. If this is the case, try to reduce the amount of bounce you're creating and lower the noise levels.
If you'd like help with your running technique, whether it's with this particular issue or any other, I offer one to one technique coaching sessions in the centre of London. Please feel free to ask any questions by getting in touch.