I just wanted to clarify what I mentioned previously. Actually it was sorely lacking. Biking is VERY popular here. “Viu BiCiNg” is Barcelona’s bike sharing service rated one of the 8 best in the world along with NYC, Paris, and others. So yes, there will be people on bikes EVERYWHERE, including on the sidewalks and other pedestrian areas. And that is when they are NOT riding in the many bike lanes that are provided. These exist in many forms and locations – here are some examples.
They may be IN the street,
BETWEEN major thoroughfares,
The above example is particularly treacherous as you have to cross 2 access roads – one on each side, 2 pedestrian zones – one on each side each with bike lanes, and 5 traffic lanes down the middle. So PLEASE BE CAREFUL, especially when running across a wide avenue with the green man on the signal blinking “run faster – you’re running out of time.” There may be someone in the bike lane right when you are “safely” out of the street.