I’m being careful not to assume that cumin will give me more energy.
Cumin didn't boost my energy. It simply allowed me to avoid feeling worse than usual (the usual PEM symptoms) that I otherwise would have experienced from activities. If I had PEM, cumin would eliminate those symptoms within a few hours. For me, cumin was a 100% effective blocker of PEM. While the cumin was active, I could do whatever physical activities I wanted to without worrying about PEM.
When you figure out how cumin works for you (Does it only allow slightly more exertion before triggering PEM, or any degree of exertion? How long does a dose last?), please post here. I only know how it worked for me.