Slow stroke rate

So, I did a 100 IM for time today and had one of the other guys video it. www.instagram.com/.../ Big thing I noticed is that my stroke rate is... glacial. Most likely this is due to having 20 more pounds of bodyweight than when I was swimming in college. Has anybody noticed something similar, and have any advice on how to rev it up a bit that might be more insightful than the obvious "just move your arms faster?" :banana: