It said Dale Oen had only had a light workout on Monday and had seemed in good health.

CNN: World champion swimmer Dale Oen dies suddenly

The output from a single workout is only enough to power a light bulb or a laptop for about an hour and saves between two to six ounces of CO2.

CNN: Virtuous cycles

Rivera wore a small, light-weight brace during Wednesday's workout, which had him also take part in fielding drills, including covering first base.

WSJ: Rivera plans to announce if this is final season