I am a runner with 37 years of it and lately have been biking almost too much. I did are first when injury starts up but now too many bike miles and the legs get weird. At one time 24 years ago a 3:06 marathon but now would love to run a 5k at that pace. Plenty of wind but cycling is different. Be careful you pace is quick for a someone who has not been running. I can run 15 miles at 10 minute pace but going under 8 for any length of time is real fast for me and cannot do that these days.