I went on a bike ride this morning in 40 degree weather and was thinking about how temperature may affect metabolism and performance. I noticed that even though my heart rate stayed relatively low, my pace was slower than usual, so I started thinking about it in terms of enzyme kinetics.
Enzymes that drive energy metabolism, like those in glycolysis and the citric acid cycle, are highly sensitive to temperature. In colder conditions, their activity decreases, slowing the rate of ATP production. This means that even with adequate oxygen and fuel, muscles may generate energy less efficiently. The lower temperature likely also reduced blood flow to my extremities, limiting oxygen delivery.
I was also thinking about this in terms of athletic warm-ups. Increasing body temperature isn’t only about preventing injury or feeling limber, but it may also optimize the conditions for the enzymatic reactions that sustain movement. In cold weather, the body has to balance thermoregulation with energy production, diverting resources toward maintaining core temperature instead of powering muscles.
I enjoyed reading your reflection because it reminds me of how my coaches made me do warm-ups or other activities to get our bodies warmed up. There was a biochemical reason behind it and I had a lack of awareness for it. It’s also interesting to see how our body has so many pathways that allow us to keep our body moving- for example running, and how when we run out of ATP, there’s creatine phosphate, anaerobic metabolism, and aerobic metabolism as a net.