The cyclical nature of commodities means that products like coal will suffer ups and downs, and it's quite possible that a surge in coal is right around the corner. That doesn't mean that every one will reap the benefits of increased demand, because coal mines in Central Appalachia are struggling to remain profitable. Higher operations costs, competition from natural gas, and environmental regulations are hitting coal mines in this region harder than anywhere else in the country, and the long-term profitability of these mines remains in question.

So which companies does this affect? Some companies like Alpha Natural Resources (NYSE: ANR) are more likely to suffer than, say, Peabody Energy (BTU), but it all comes down to how much exposure these companies have to Central Appalachia coal. Tune into the video below where Fool.com contributor Tyler Crowe takes a look at which companies should be on notice.