1. Food, as already said, but so very important it bears repeating. I've found there's nothing like a lack of available chemical energy (or water to facilitate the reactions) to drag down my kinetic expenditure. Just being aware of this is helpful, e.g., "I don't feel like doing anything… Wait, I haven't eaten right today… OK, time to fight through that now that I know the cause isn't some cosmic force outside my control!"

2. I've found I've a strong connection to musical context, i.e., when my ass is dragging, playing tunes I have listened to while doing things I find fun (in my case, careening down mountains on bikes with earbuds in) can give me a good jolt out of a lethargic moment.

3. Redirect the slack. Few time-wasters out there compare with surfing the web. So, if I'm falling down that rabbit-hole, I surf to find things I find motivating and energizing, e.g., reading about the training regimes of athletes I admire, or find youtube clips of them demonstrating significant badassery, or finding training clips I can follow (I've been enjoying Ryan Leech's 30 Day Wheelie Challenge lately.)

4. Take a nap. In the sun if possible.

5. Listen to Car Talk (while eating some proper food, but be careful with liquids that can come back through the nose.)

6. Smile. If you can't do #5, just plaster a big, fake grin on your face. I find it rare my brain doesn't say "hey, we're smiling here, crap we must be happy and energized and I just missed the memo, time to get on that!"