REF-1450 · Evertsen et al., 2001 · Acta Physiologica Scandinavica · Paper · PubMed

Does harder training move the lactate threshold more?

20 elite skiers, 5 months: training at 80-90% of VO2max raised speed at the threshold 3.2%, at 60-70% it did not, and the groups differed. Allocation not stated; abstract only.

Main caveat: Abstract only; closed access. Arm sizes, allocation, training content and volume unknown.
limited, mixed evidenceMeasured on highly trained to elite athletes

Evertsen, Medbø and Bonen (Norwegian University of Sport and Physical Education) followed 20 elite cross-country skiers who trained hard for 5 months at either moderate (MIG, 60-70% of VO2max) or high intensity (HIG, 80-90%).

Lactate threshold, several performance parameters, blood lactate after exhausting treadmill running, and vastus lateralis MCT1, MCT4, fibre types and six enzymes were measured. MCT1 did not change for HIG (P = 0.3) and fell for MIG (−12 ± 3%, P = 0.01), with a different response between groups (P = 0.05); MCT4 did not change.

Running speed at the lactate threshold rose for HIG (+3.2 ± 0.9%, P = 0.003), not for MIG (P = 0.54), again with a different response (P = 0.04). Lactate after long exhausting running correlated with MCT1 (rs = 0.69, P = 0.002), not MCT4. The authors conclude high-intensity training "may be more effective for cross-country skiers".

Our reading: one of the few intensity trials in the base with women in numbers, and it has a real between-group result, unlike many in this literature. It supports "training at 80-90% of VO2max moved the threshold more than training at 60-70%, in elite athletes"; that the upper band sits near the threshold is our inference.

It does not test whether that holds when easy volume has stopped working, and the abstract describes no control group on habitual training. Neither the volume nor the share of total training in these bands is stated, so "trained at 60-70%" cannot be read as all their training.

Protocol

Participants: n = 20 elite cross-country skiers (11 men, 9 women).
Training: hard training for 5 months at 60-70% (MIG) or 80-90% (HIG) of VO2max; session content, volume and arm sizes not in the abstract.
Tests: lactate threshold (running speed), several performance parameters (not itemised), blood lactate after exhausting treadmill running.
Biopsies: vastus lateralis before and after, MCT1, MCT4, fibre types, six enzymes.
Funding and interests: PubMed lists "Research Support, Non-U.S. Gov't" without naming the funder; no conflict statement in the record.

Key Results

OutcomeMIG (60-70% VO2max)HIG (80-90% VO2max)Between groups
Running speed at lactate thresholdno change (P = 0.54)+3.2 ± 0.9% (P = 0.003)P = 0.04
Muscle MCT1−12 ± 3% (P = 0.01)no change (P = 0.3)P = 0.05
Muscle MCT4no change (P > 0.10)no change (P > 0.10)not given
Sex: MCT concentrations did not differ between women and men (P = 0.9).
Correlation: lactate after long-lasting exhausting running with MCT1, rs = 0.69, P = 0.002; with MCT4, rs = 0.2, P = 0.2.
Not in the abstract: absolute speeds, VO2max change, other performance values, race results.

Mechanisms

Measured: threshold speed and MCT1 responded differently between intensity groups.
Authors' interpretation: high-intensity training may be more effective for these skiers; MCT1 may matter for releasing lactate to the blood during long exercise.
Inference: a fall in MCT1 at 60-70% of VO2max cannot be read as harm; no performance link was shown beyond the correlation above, and other correlations with MCTs were not significant.

Practical Application

Does harder training move the lactate threshold more? 20 elite skiers, 5 months: training at 80-90% of VO2max raised speed at the threshold 3.2%, at 60-70% it did not, and the groups differed. Allocation not stated; abstract only.
What it is good for: a between-group result for "80-90% of VO2max moved the threshold more than 60-70%" in elite athletes, with women included, to read beside REF-1442 (B+) and REF-137 (B+). The numbers apply to elite skiers over 5 months. Not from this paper; the base's own practice for amateurs is one or two sub-threshold sessions inside the quality budget (SYNTH-03, SYNTH-27).
What it does not show: an effect in amateurs, that the upper band is better than intervals above threshold, that lower-intensity work is useless (these were elite athletes; their history is not in the abstract), or race outcomes. It tested no named band such as sweet spot.

Limitations

Abstract only; closed access. Arm sizes, allocation, training content and volume unknown.
About 10 per arm (our arithmetic), one sport, elite; the abstract does not state whether men and women were balanced across arms.
Threshold outcome is running speed in skiers, a test specific to neither race nor technique.
Multiple correlations with few significant; hypothesis-level.
2001 study; the threshold method is not given in the abstract.
Funding: non-US government support per PubMed, funder not named in the record.
How this entry was checked and changed
Why this level

(from the abstract) — the rubric's B for a small parallel study, lowered a step on the same ground as REF-1451: an abstract-only small study whose key methods (allocation, arm sizes, training content and dose) are missing; the between-group test in elite athletes, including women, is its strength, and the full paper could lift the level