I'm running a solo time trial for the 1600m, and I've noticed that I end my first lap solid, but I tend to slow down a lot. Physically, I'm worn down but still have a lot of energy I'm not expending well. I tend to slow down and settle into a pace that I could be going faster with, and I'm trying to hit a goal pace. Any help with this? Or should I just get a watch to keep me on pace?