Media playback is not supported on this device
Well 68-year-old Paul Mounsey is living proof that you are never too old for it.
"My category is 45 plus...so I'm racing against guys 20 years younger than me," says Paul who started riding just five years ago aged 65.
"I saw the BMX and I thought 'I'd like to give that a go at this' and here we are!"
Find out how you can get into BMX, no matter how old or young you are, by visiting our cycling activity guide.
BMX racing is a young man's game, right?