Do you feel that you use your thighs a lot? When running you’re not sure but think you are. But when you cycle you just know that clips don’t do that much for you and that you ARE using your thighs a lot.
Well then you probably are using your thighs too much! So when running your action is focussing more on the start of the stride ie lifting up the leg rather than the push through and off. Sounds a bit technical but basically you want as many muscles working for you as possible! Not just your thigh – albeit one of the larger muscles you possess.
The problem with the overt focus on the thigh is that it tends to stick your foot out too far in front of you. So when it hits the ground all your body mass goes crunching down your leg to your foot before your body heaves over and you push off. You basically almost stop doing it this way. Your leg striking the ground almost acts as a break.
So is the solution to focus on technique or alternatively to focus on building up hamstrings and calves so that the technique can be improved once the strength is there? Well I’m not sure. But I am sure that you won’t be able to do the right technique at speed untill your underused muscles are a bit stronger. So I would focus on strengthening your weedy hamstrings and calves. I have a friend who falls in this category and whilst he does have weedy calves he still does a sub-19minute 5k. So you can have weedy bits but still pull off quite respectable times.
The exercise: Do this quite a bit. The old kick your bum with your heels. Run your shorter faster intervals a bit slower than normal but do the bum kick to expend lots more energy than you normally would. Super strong hamstrings and calves here we come!