My cycling pace for 10-15 miles is 22-23 mph. My run pace for a 5k is 6:30 a mile. My friend bikes 12 miles at 22 mph, but his 5k pace is 8:30 a mile. To me this doesn't make sense. Is there a formula that correlates the two?? I know it is different muscles & mechanics, but it seems like there would be a loose connection.