Threshold speed is built by running
High confidence
Your lactate threshold is the pace where easy effort tips into hard. To raise it, you have to train it by running. Cycling or rowing at the same effort keeps you fit, but it does not move your running threshold the same way.
Why it works
Your body builds threshold partly around which muscles fire in a given sport and around changes in the tiny engines inside those muscle cells (the mitochondria). Running trains the running pattern, so another sport does not fully carry over.
What it means in practice
If you're injured and wondering whether cycling can stand in for your tempo runs, the answer is partial. Cycling keeps your heart and lungs fit, but threshold-pace running only comes from running. In a plan, tempo and threshold sessions work best done as runs, not cross-training.
The evidence
-
Lactate-threshold gains stayed specific to the trained mode, while VO2peak gains transferred across modes; the pattern suggests peripheral, muscle-level threshold adaptation against central VO2peak gains that carry over. Run training raised VO2 at LT more on the treadmill (+58.5%) than the cycle ergometer (+30.3%), a significant mode difference. Cycle training raised cycle-ergometer VO2 at LT by 38.7% but produced no significant treadmill change (23.6 to 24.0 ml/kg/min). VO2peak rose 11.9% to 20.7% in both training groups regardless of test mode, and controls held flat; all of this comes from 16 untrained men over 10 weeks in 1990.
n=16
-
Modern elite triathletes reach VO2max values on par with elite single-sport runners and cyclists, reversing the 1980s conclusion that multi-sport training compromised aerobic capacity. Male triathlete ranges span 49.7-78.5 ml/kg/min running, 43.6-75.9 cycling, and 49.9-57.7 swimming; female ranges span 50.7-65.6, 48.2-61.3, and 38.1-45.3 across the same disciplines. Running VO2max sits consistently above cycling, and cycling above swimming, regardless of training background, while lactate threshold and ventilatory threshold also match single-sport athletes when measured by similar methods. Cross-training transfer looks meaningful between cycling and running but limited between swimming and the other two disciplines.
Why we call confidence high
Pierce (1990) is the foundational study here, and Suriano (2010) confirmed it in triathletes. Threshold work in another sport, like cycling or rowing, does not transfer fully to running threshold pace.
Where it applies
Trained runners and multi-sport athletes who cross-train to build aerobic fitness.
Does not apply to: beginners building general aerobic base, where any modality contributes.
Plans that respect this
Plans that scored well on the rubric measures informed by this claim.
- 10-Week Run Your First 10k (3 days)
- 10-Week Run Your First 10k (4 days)
- 10-Week Run Your First Half Marathon (3 days)
- 10-Week Run Your First Half Marathon (4 days)
- 10-Week Sub-1:30 Half Marathon (4 days)
- 10-Week Sub-1:30 Half Marathon (5 days)
- 10-Week Sub-1:30 Half Marathon (6 days)
- 10-Week Sub-1:45 Half Marathon (4 days)
- 10-Week Sub-1:45 Half Marathon (5 days)
- 10-Week Sub-1:45 Half Marathon (6 days)
- 10-Week Sub-2 Half Marathon (3 days)
- 10-Week Sub-2 Half Marathon (4 days)
Last reviewed Apr 30, 2026. See how we score.