Depends on the cyclist. In my usual daily cycle, I'm not panting or heaving big breaths; I'm sailing along breathing in the good air (I avoid car-heavy roads) as I sit and pedal gently.

Occasionally, being a wimp, I have to get off and wheel my bike up a hill; mostly I can get up hills by using lower gears, though, and it doesn't require any great deep lungsful of air. In fact, the only difference in my breathing when I cycle is that it is probably closer to meditation breathing.

By the way, the latest news is that we were all wasting out time avoiding butter and pizza (assuming we were eating healthily generally and taking exercise) https://www.irishtimes.com/news/health/cutting-saturated-fat-does-not-reduce-heart-disease-experts-say-1.3061769