Tempo & Threshold Runs

What they are (and how they differ)

Both sit near your lactate threshold — the fastest effort you can sustain before fatigue snowballs (see the lactate threshold article). A tempo run is a sustained effort a notch below threshold: "controlled discomfort" you could hold for a while, breathing deeper but rhythmic, able to get a few words out at a time. A threshold session works right at the line, usually broken into longer intervals (cruise intervals) so you can bank time at the right intensity without it tipping over.

Why they work

Training at and just below threshold improves your body's ability to clear lactate and use oxygen at hard efforts, which raises the pace you can hold before fatigue takes over¹. In plain terms: it lifts your sustainable race pace. That's why threshold work is the cornerstone of half-marathon training and a staple of marathon builds.

How to structure them

Always warm up first — 10–15 minutes easy — then do the work, then cool down. Common shapes:

• Continuous tempo: 20–40 minutes sustained at comfortably-hard effort (roughly your one-hour race effort).
• Cruise intervals at threshold: e.g. 4–5 × 5–10 minutes at threshold with short (1–2 min) jog recoveries — more total time at intensity, less strain than one long block.

Pace by effort, not ego

The discipline is staying *at* the line, not drifting over it. If the last reps turn into a race, you've gone too hard — threshold gains come from controlled, repeatable efforts, not from turning every session into a time trial. Hold something back and let the pace come to you over a block of weeks.