Tempo Run Guide
You planned 30 minutes at “comfortably hard.” Split one comes in 10 seconds/km too fast, breathing already clipped. That is how tempo becomes a disguised VO2 session. Tempo trains the pace you can hold while uncomfortable but controlled — roughly lactate threshold — without the recovery cost of all-out intervals.
Find Tempo Without Guessing
- Often ~25–40 sec/mile slower than 5K, or near 10K–half effort depending on definition
- Feel: short sentences, sustainable 20–40 minutes
- Seed from a recent race via the Pace Calculator, Pace Chart, or Race Predictor
- HR often near Zone 4 / LT — set zones with the HR Zones Calculator
Worked Scenario: 48:00 10K Runner
10K in 48:00 (~4:48/km). Continuous tempo target ≈ 4:55–5:05/km. Cool Tuesday: 25 min at 5:00/km, HR settling near 168 after 8 minutes — controlled. Hot Thursday attempting the same 5:00/km hits 178 by minute 12 with fading form. Decision: slow to 5:10–5:15/km or switch to 3 × 8 min cruises with 2 min jog so average intensity stays threshold, not redline. Related physiology: lactate threshold guide.
Do not let Garmin/COROS “aerobic Training Effect” push you faster mid-tempo. Wrist HR also lags surges — pace and RPE lead for the first 5–8 minutes; HR confirms once steady. If easy days that week were secretly Zone 3, skip tempo and fix easy first.
Session Shapes That Work
- Classic: 20–40 min continuous after warm-up
- Cruise intervals: 3–5 × 8–10 min at tempo, 2 min jog
- Progressive: easy → moderate → last 15–20 min tempo
- Tempo finish long run: mostly easy, last 15–25 min tempo
One quality tempo or cruise session weekly is enough for most recreational plans (5K, 10K). Build duration before chasing a faster tempo pace.
Where It Fits in the Week
Place tempo mid-week with easy running the day before and after. For half-marathon prep, continuous 25–35 min or 3 × 10 min cruises beat random “kinda hard” runs. Keep long runs mostly easy until late-specific blocks so threshold work stays sharp.
Decision Rule
If the first 5 minutes of tempo already feel like a 5K effort or HR is still climbing hard past minute 10 at goal pace, slow 5–10 sec/km or cut to cruise intervals. If pace and breathing stay “controlled hard” through the planned duration, hold the target and keep surrounding days easy.