1) I usually bike on a low-resistance setting where I can talk without being out of breath (similar to talking and walking). If I’m on a higher setting and I need to talk, I just stop biking.
2) I was going to insert a joke about meetings and meaningful contributions here. But more seriously a lot of meetings are about synchronisation, which means that I spend most of my time listening. Believe it or not, it’s easier to concentrate on what everyone is saying when biking rather than, for instance, reading your emails or browsing the internet.