REF-817 · Esteve-Lanao et al., 2005 · Medicine & Science in Sports & Exercise, Vol. · Paper · PubMed

How Do Endurance Runners Actually Train? Relationship with Competition Performance

Blimited evidenceMeasured on highly trained athletesWritten before October 2026, being re-checked

Eight well-trained subelite endurance runners (23 ± 2 yr; VO2max 70.0 ± 7.3 mL/kg/min) had heart rate recorded in every session over a 6-month macrocycle (late August to mid-February) aimed at national cross-country championships (4.175- and 10.130-km races).

Time was counted in three zones set from a maximal test: zone 1 below the ventilatory threshold (VT), zone 2 between VT and the respiratory compensation threshold (RCT), zone 3 above RCT. Total time in zone 1 (4581 ± 979 min) was far higher than in zone 2 (1354 ± 583 min) and zone 3 (487 ± 154 min), and zone 2 exceeded zone 3.

Time in zone 1 correlated with performance time in the short (r = -0.79, P = 0.06) and long race (r = -0.97, P = 0.008). The authors suggest that time at low intensity may be associated with better performance in intense events of about 35 min, and call for interventional studies.

Participants

Eight well-trained, subelite endurance runners; age 23 ± 2 yr; VO2max 70.0 ± 7.3 mL/kg/min. Sex is not given in the abstract.

Protocol

Maximal cardiorespiratory test before the training period to set VT and RCT.
Heart rate recorded continuously by telemetry in every session over a 6-month macrocycle (late August to mid-February).
Zones: 1 = below VT; 2 = between VT and RCT; 3 = above RCT.
Outcome: performance time in the season's key cross-country races (4.175 and 10.130 km, national championships).

Key Results

Total time in zone 1: 4581 ± 979 min, significantly higher (P < 0.001) than zone 2 (1354 ± 583 min) and zone 3 (487 ± 154 min).
Time in zone 2 was significantly higher than time in zone 3 (P < 0.05).
Time in zone 1 vs race time: r = -0.79 (P = 0.06) for the short cross-country race; r = -0.97 (P = 0.008) for the long race.
Authors' conclusion: total training time at low intensity might be associated with improved performance in highly intense endurance events, especially of approximately 35 min; interventional studies are needed.

Practical Application

"Does all that easy running actually matter?" — in eight well-trained subelite runners followed for six months, most training time fell below the first ventilatory threshold (4581 ± 979 min against 1354 ± 583 min between thresholds and 487 ± 154 min above), and more time in that easy zone went with faster cross-country races (r = -0.97 for the longer race): the easy layer is the bulk of the work and tracked performance.
Protect the easy volume: in these runners it was the largest block of training and the one tied to race times.
The distribution was pyramidal (zone 2 more than zone 3), not strictly polarized.
Correlation, not proof: the same group's randomised follow-up tested the idea directly (REF-094).

Limitations

Eight runners; correlations, one of which (short race) did not reach P < 0.05.
Heart-rate zones may undercount time at high intensity in short intervals.
Zone 1 time also reflects total volume; the abstract does not separate the two.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

observational, n=8, correlations only