Evolution of Physiological and Haematological Parameters with Training Load in Elite Male Road Cyclists: One-Season Longitudinal Study
Zapico and colleagues followed a group of elite male road cyclists through one season to evaluate physiological parameters as a tool for monitoring training. The abstract does not state the number of cyclists.
Protocol
Season split into two mesocycles — a winter "volume" period and a spring "intensity" period — with laboratory tests between them
Tests: ramp test to exhaustion (work load increases 25 W/min) and a maximal lactate steady state (MLSS) test on a cycle ergometer
Training volume and intensity of every session recorded across the study; macronutrient intake and haematological variables recorded during the test periods
Key Findings
Physiological profile matched professional cyclists: peak power approximately 450 W, VO2max approximately 78 mL/kg/min; MLSS approximately 250 W
After the first (volume) period, both thresholds moved up: VT1 from ~52% to ~60% of VO2max and VT2 from ~82% to ~87% of VO2max — even though that period was low-intensity, with 77% of training in "zone 1" (below VT1)
MLSS power rose after the first period (~225 → ~250 W) and stayed high in the second (~255 W)
Haematology and biochemistry: high creatine kinase (~230 U/L) and urea (37 mg/L), and a fall in haemoglobin (~15.4 → ~14.7 g/dL) over the season
Authors' conclusion: the level reached after the first period suggests two effort tests may be enough to plan training; the decline in red-cell and nutrition parameters argues for closer monitoring of them during the season
Practical Application
Elite male road cyclists (~78 mL/kg/min, ~450 W) followed through one season (Zapico 2007): a winter mesocycle with 77% of training below VT1 raised VT1 from ~52% to ~60% and VT2 from ~82% to ~87% of VO2max and lifted MLSS power from ~225 to ~250 W; the spring intensity mesocycle added little more (~255 W) while haemoglobin fell (~15.4 → ~14.7 g/dL) and creatine kinase and urea ran high.
The volume period did the threshold work: most of the season's threshold gain came from the low-intensity-dominated mesocycle, not from the later intensity block.
Monitor the cost of the season, not only the fitness: falling haemoglobin and high CK/urea in the same riders are the flags the authors want tracked.
Inference, not tested: two laboratory tests a season (after the volume block, then late season) may be enough to steer training in this population.
Not from this paper; the base's own practice: a long easy-dominated base before the intensity block, and a blood check when a heavy season starts to show fatigue markers.
Limitations
Observational, one season, no control group; the abstract does not state the number of cyclists.
The training distribution is given only for the first period (77% zone 1); no zone split for the intensity mesocycle is reported in the abstract.
Elite men (Tier 4) at professional-level power; the absolute values do not transfer to amateurs.
Haematological changes are descriptive; no causal link to training load is established.
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B+: small observational cohort, one season, no control group
Content correction 2026-09-27
"2-year training logs", "over 2 seasons" -> one season in two mesocycles (winter volume, spring intensity).
"Early season 70-75% low / 8-10% high; mid-season 60-65% low / 25-30% high; late season 80-85% low / 5-10% high", "compliance with planned distribution", "distribution reflects polarized model" -> invented; the abstract reports only 77% of training in zone 1 (below VT1) during the first period. Added VT1/VT2, MLSS, power, VO2max, CK, urea and haemoglobin values.
"14-week plan aligns with elite structure (weeks 1-6 / 7-10 / 11-14)", "threshold-heavy mid-season is a common amateur error" -> house advice, not from this paper; removed.
Level B+ -> B (small observational cohort, one season); Tier 5 -> Tier 4 (elite male road cyclists); title corrected to the paper's.
2026-09-29: PMID 17557057 (already named in the Journal line) moved to its own PMID field after verification on Europe PMC — author, year, journal, volume and pages match; no DOI exists for this article (Europe PMC record carries none, Crossref title search finds none).