Sort of, riding for a ‘proper’ team for the first time this season.
Training varies according to all sorts of things, mostly when races are, injuries and weather, usually 1000-1200hrs per year.
Diet varies according to training. I’m veggie all the time (moral reasons rather than anything to do with racing) Mid season I’ll be eating 6000 calories per day average, maybe down to 4000 off season (5’11 and 10st2) and lots more when there’s a 24hr race.
I just change parts when they break. New stuff at the start of each season would be brake pads, inner gear cables, chain, cassette, middle ring and tyres. The tyres and pads would usually be a changed a few times a year. Old stuff gets moved down the line to spare bike, then to commuter. Only get reduced rates on frames, bars, stems and tyres so still need to look after it.
I expect all of the above would be hugely different for downhillers. Especially the bit about changing parts when they break…