Hi Huffandpuff, welcome to TE! I love your screen name.

Frankly, and although intervals and such are great things to do just to improve your cardiovascular fitness generally, I wouldn't worry too much about it. Rather, I'd suggest focusing on letting go of the idea that you and your husband should be riding at the same speed, and just enjoying your ride. You can try to close the gap on him to some extent, but men just are more powerful then women in most sports. Sure a tandem might be a good idea too, if you really need to be that close together. Or practice your drafting skills so you can stay on his wheel, benefiting from his draft. But drafting is pretty useless on hills, and being from Quebec I know how hilly your beautiful State is. Unless you're planning to race, your speeds look just fine to me.

Here's where I'm coming from. I'm a reasonably fit road cyclist, although I've never wanted to be a racer. My husband is among the strongest riders I know of, short of pro racers. He excels on climbs especially. On flats, I can hold on to his wheel (drafting) for my dear life. It takes me quite a bit of effort, and for him it requires stepping it down a couple of notches. On hilly terrain? Forget it. He does, in fact, ride in circles around me: I have him ride ahead, and eventually turn around and come back to meet me. On the big climbs of the Alps in France, I sent him ahead, and I knew when I was about halfway (on a 30km climb) he was already at the top. He'd turn around, meet me wherever I was, and do the rest of the climb again with me. He was a bit tired by then so it was easier for him to ride at my pace. He'd also ride ahead and snap pictures. I get my revenge on descents: I'm a fearless descender and he hates it, so it's me who has to wait for him on those long, long downhills. On rollers I also have a pretty good chance to keep up with him because I've become good at making the most of every little downhill I can get. On flat rides sometimes he'll get ahead, make a right turn onto a steep-looking hill, and I just keep doing my thing. Eventually he'll come back from behind. We are never separated for too much more than 10-15 minutes.

The hardest thing in all this was for us to manage this on the psychological side. He hated to get too far away from me, because he though I would be feeling bad about it. I hated to have him in sight, while knowing there was no way I could catch up with him, always working way above what was enjoyable for me, ruining my ride. It took us years to handle that, but now he knows when he should stick with me (flat grounds, especially with a headwind, where I want to draft off him) and when he has to take off and do however he pleases (on hills).

Good luck! And enjoy your ride.