I have been ridng for years, more so recreational than competitive. I have always riden alone but this summer I have tried to up my performance by keeping a close log of my riding, my HR and nutrition. I am seriously trying my best. I just completed my first half century this past weekend and as noted in another post I completed it in around the 200 mark at an average speed of about 28.2 KM/H. After seeing so many posts about speed and distance I'm thinking to myself that I am so off the mark that if I were to ride with someone or even consider racing I would not stand a chance. My question to everyone is I have always felt that my endurance is strong. I very rarely slow my cadence down. What I need to know is how best to improve speed. I know intervals help but how do I best utilize them? Could my gearing be incorrect? Sometimes I watch local races or tri's and it seems that there pedaling is so smooth that they very easily maintain speeds in the mid to high 30K mark. With Intervals do you go all out for 30 seconds and then cool down for 30 or do you maintain a good speed for 30 then cool down? Really confused please help because I would really like to ride with someothers I just hate the feeling that I would be holding up riders because of my slow pace.