Political rallies come in all shapes and sizes—and speeds. Spanish trade unionists amble gently, carrying banners at a leisurely pace. French manifestants in 2018 occupied roundabouts during the “yellow vests” movement, milling about as cars zoomed past their encampments. Those wishing to meet the protesters who have gripped Serbia for the past five months will need a touch more energy, and a pair of trainers. University students marching down Belgrade’s boulevards do so at such a brisk clip that out-of-shape middle-aged types—including this visiting columnist—can find it hard to keep up. Luckily, anyone running out of puff can simply fall behind and wait for the next of a slew of parades organised throughout the day to speed-march their way past. Onlookers of all ages seem to have a whistle tucked away in a pocket, ready to contribute to the cacophony generated by a few dozen or hundred students scurrying along. Five minutes later all is quiet again, until the next lot arrives.