Last November, we wrote about transcranial direct-current stimulation (tDCS), a new brain-stimulation treatment that seems to boost exercise capacity.  

And, boy, were we ahead of the curve.

In a study at the University of Kent in the U.K., nine guys in their 20s did leg extensions at about 20% of their max; but when tDCS electrodes jolted their heads with a tiny bit (2 milliamps) of juice, their perceived effort lessened, allowing them to exercise about 15% longer—which researchers translate to being able to go longer during endurance exercise. 

However, the researchers stress these optimal performance effects only happened when the tDCS electrodes, which deliver the electrical current, were positioned in a particular way. You really need professional guidance to make sure you're applying the tDCS correctly; in fact the authors warn against the uncontrolled use of tDCS.

You can buy a tDCS device at thebrainstimulator.net, but ask your doctor first and seek expert guidance.