​One way to really improve running off the bike, and triathlon running in general, is deep water running (DWR). This is running in the deep end of the pool without touching the bottom at all.

Wear a buoyancy vest for extra floatation and this will assist holding good run form in the water. I have had great success as an athlete and coach incorporating DWR as part of an overall training program rather than purely as training for injured runners. DWR will engage your run muscles in the hip flexors and hamstrings. It really helps your knee lift and is a resistance training exercise – working against the water. Basically you can get easy run mileage for very little expense as far as body wear and tear and breakdown is concerned.

A 40min run in the water = 1hr road run as far as aerobic strength is concerned.