X @The Economist
The Economist·2026-03-06 19:50
As exercise gets more intense, the heart rate rises to deliver more oxygenated blood to working muscles. But there is an upper limit https://t.co/Ij153MLjj5 ...
As exercise gets more intense, the heart rate rises to deliver more oxygenated blood to working muscles. But there is an upper limit https://t.co/Ij153MLjj5 ...