What is a tempo run?
A tempo run is a sustained effort at comfortably hard pace, roughly your 10K to half marathon race pace, held for 20-40 minutes. It builds lactate threshold — the maximum pace you can hold without accumulating lactic acid. Effort should feel hard but controlled, around 85-88% of max heart rate.
A tempo run, also called threshold run, is the cornerstone of endurance training for 10K to marathon runners. The purpose is to train your body to clear lactate as fast as you produce it at increasing paces — effectively raising your 'lactate threshold,' the point at which running shifts from aerobic to anaerobic metabolism. In practical terms, tempo pace is 'comfortably hard' — you can speak 2-3 word phrases but not full sentences, your breathing is controlled but deep, and you could sustain the effort for about an hour at maximum. For most recreational runners, that's somewhere between 10K and half marathon race pace, or 30-40 seconds per km faster than marathon pace. A typical tempo session: 15 minutes easy warm-up, 20-30 minutes at tempo pace, 10 minutes easy cool-down. More advanced variations include 2 x 15 minutes with 3 minutes recovery, or long tempo runs of 40-50 minutes at slightly slower pace. Do one tempo session per week during base and build phases. Done correctly, 8-12 weeks of tempo work can drop your 10K time by 30-90 seconds. Done too fast, it becomes a VO2max workout and produces burnout instead of gains.