a head of cheese,a bottle of wine,akeg of whisky all improve with age not so the human body when i first started cycling about 6 years ago [at 79]i could do the local creek valley trail on an mtb with very little problem... two years later the exit hills[short,but very steep]were a real grunt.. i put a motor on the mtb ...about 80% pedal... this year , its about 70% power... the rate of decline seems to increase each year,YYUUUKKKK