Sure, think of endurance as a balance between energy supply and demand. A quick rule of thumb is to keep your heart rate at about 70–80 % of your maximum (max HR ≈ 220 – age). Then, use the power–time relationship: \(P = \frac{E}{t}\). If you want to improve, increase \(t\) (time at that power) while keeping \(P\) constant, or slightly increase \(P\) while keeping \(t\) stable. In practice, run for 30 minutes at 75 % HR, then add five minutes every few weeks. Repeat. That incremental linear growth tends to produce the most sustainable gains.