However, since Greece shares the Euro with 15 other nations and is a very small portion of Euro-zone economic activity, most of the real income adjustment has to come through declining money wages, benefits, etc.

FORBES: Greece Needs To Exit The Euro Zone

Users can personalize their workouts by selecting their type of activity, target training zone and type of workout.

ENGADGET: Scosche myTrek sends workout vitals to your iPhone, starts shipping now for $130 (video)

Separately, a measure of euro zone manufacturing activity was better than expected.

WSJ: Stocks Hit New Highs

The euro zone's purchasing-managers index, a gauge of manufacturing activity, fell in November to a level consistent with a 1% quarterly drop in gross domestic product, according to research firm Capital Economics.

WSJ: How to Play the Central-Bank Rescue

Investors are hoping that a recent decision by central banks of the United States, the euro zone and Britain to lend billions in multiweek loans will boost activity in the global debt markets.

FORBES: ECB Lubricates Banking System With $500B