Increasing your carb intake on different days.
A bit more specific:
Increasing your carb intake on days that you exert a serious amount of effort moving heavy things.
Stick to white rice / sweet potatoes / white potatoes / fruit to up your carbs.
Stay off wheat.
For this to be effective, you need to be sensitive to insulin. So if you're 50+ lbs overweight, it's probably not a good idea.
If you do this, keep your fat below 40g on carb refeed days.
I'm sure others will chime in with other thoughts.
btw, search for chocotaco369's thread on carb refeeding...tons of info.