I think some of it depends on who you are. When I got back on the bike after an 8 yr. absence I was 59 yrs old. I was 25 lbs overweight and out of shape. It took me a couple years to get back into some sort of reasonable condition and lose some weight. Then I plateaued...mainly because I refused to modify my eating and drinking habits. This past year I finally made some dietary changes...lost 13 lbs and am faster now at age 65 than I was two years ago or even last year. I'm looking forward to losing another 10 lbs and getting back to my college football weight. I should be even faster next year and that's my focus.