REF-301 · Casado A, Foster C, Bakken M & Tjelta LI, 2023 · International Journal of Environmental Research and Public Health, · Paper · PubMed
Does Lactate-Guided Threshold Interval Training within a High-Volume Low-Intensity Approach Represent the "Next Step" in the Evolution of Distance Running Training?
Key Results
Describes lactate-guided threshold interval training (LGTIT) within a high-volume, low-intensity approach — the training pattern of some world-class middle- and long-distance runners — and reviews the physiological mechanisms that may explain it
Weekly structure: three to four LGTIT sessions plus one VO2max-intensity session; low-intensity running fills the rest up to 150-180 km/week
Intensity control in LGTIT: pace is dictated by a blood-lactate target, typically 2-4.5 mmol/L, measured every one to three repetitions — internal rather than external load
Why threshold, not harder: that intensity may allow faster recovery (lower central and peripheral fatigue) between sessions than higher intensities, hence a greater weekly volume of these specific workouts
Why intervals, not continuous: the interval format allows high absolute training speeds and so maximises the number of motor units recruited, despite a relatively low metabolic intensity (threshold zone)
Full text, checked 2026-09-27: the LGTIT sessions are typically organised as double-threshold days (AM + PM) on the same day
Mechanism
From the review: lower central and peripheral fatigue at threshold intensity → more specific work per week; high absolute speeds in interval form → more motor units recruited; the model may increase mitochondrial proliferation by optimising both calcium and AMPK signalling pathways. Not from this abstract: MCT transporter and capillarisation claims.
Practical Application
Narrative review of the world-class Norwegian distance-running model: 3-4 lactate-guided threshold interval sessions per week at 2-4.5 mmol/L (lactate checked every 1-3 reps), one VO2max-intensity session, and easy running to 150-180 km/week. The quality is concentrated at threshold because that is what can be repeated three to four times a week; the one hard session covers VO2max.
Intensity control by lactate, not pace — the target is a blood-lactate band, and the pace follows from it on the day
Intervals, not continuous: the interval format is what lets threshold work happen at high absolute speed with many motor units recruited
Easy running is the bulk of the volume; the model is high-volume first, threshold-interval second
Limitations
Narrative review — no original data; describes a model used by a small number of world-class runners
Based on Norwegian running (transferability to cycling or to sub-elite volumes assumed, not proven)
Individual variation in optimal lactate target not addressed
How this entry was checked and changed
Content correction 2026-09-27
Added the model's weekly structure from the abstract: 3-4 LGTIT sessions + 1 VO2max session per week, low-intensity running to 150-180 km/week, lactate 2-4.5 mmol/L measured every 1-3 reps.
"Twice on the same day, 2 days/week", micro-interval durations (45-60 s / 15-30 s), "5500+ lactate tests", ~3.0 mmol/L, 20-40 min work, <70% HRmax, cycling 95-100% FTP translation -> not in the abstract; removed or marked full text / not from this paper.
Sport cycling/running -> running.
Lines labelled "full text; not checked" were read against the open-access full text (PMC10000870): 1 confirmed and relabelled.
Full text (checked 2026-10-12)
Sample week: Tuesday AM 5 × 6 min at 2.5 mmol·L−1 with 1 min recovery and PM 10 × 1000 m at 3.5 mmol·L−1 with 1 min recovery; Thursday AM 5 × 2 km at 2.5 mmol·L−1 with 1 min recovery and PM 25 × 400 m at 3.5 mmol·L−1 with 30 s recovery; Saturday 20 × 200 m uphill at 8 mmol·L−1 recovering 70 s jogging back (z4) (full text, Table 2).
The same sample week includes sprints (z5) and technique on Monday and Wednesday evenings, strength training on Wednesday, and a 21 km easy run on Sunday (full text, Table 2).
The Ingebrigtsen brothers ran LGTIT repetitions of 2000 m to 3000 m at close to half-marathon pace and 400 m to 1000 m at paces between 5000 m and 10,000 m race pace, with session volume between 8 and 12 km and recovery between 20 s and 1.5 min (full text).
The authors observed international level runners doing 20–25 × 400 m in 64 s with 30 s recovery and 20 × 400 m in 62 s with 60 s recovery while [BLa] stayed below 4 mmol·L−1 (full text).
Weekly volume in this model is 157–185 km/week, and the longest run does not exceed 21 km (full text).
In the competitive period the z5 hill session is partly replaced by track workouts at competition pace at 5 to 10 mmol·L−1, and two LGTIT sessions are removed from the week (full text).
The zone table puts z2 at 2–3.5 mmol·L−1 (82–87% HRmax) and z3 at 3.5–4.5 mmol·L−1 (87–92% HRmax) (full text, Table 1).
The authors state that no controlled studies have tested the model and that it has been described only in 1500 m and 5000 m runners, with applicability to the marathon uncertain (full text).