REF-1452 · Gaskill et al., 1999 · Medicine & Science in Sports & Exercise · Paper · PubMed

Will athletes who stall on easy volume respond to more intensity?

7 poor-responding skiers raised high-intensity share (under 17% to over 35%) and improved. Picked for a poor year, not randomised: may be rebound. Abstract only.

Main caveat: Non-randomised, selected on response; regression to the mean is the main rival explanation.
limited, mixed evidenceMeasured on trained to highly trained athletes

Gaskill and colleagues (University of Montana) evaluated cross-country skiers (N = 14) for VO2max, VO2 at threshold, lactate response, maximal arm power and competitive results after a standard training year.

In year two they divided them into a control group of those who had responded well (N = 7), who repeated the same programme, and a treatment group of those who had responded poorly (N = 7), whose high-intensity time rose from under 17% to over 35% of total training and whose low-intensity volume fell 22%.

The treatment group significantly improved VO2max, VO2 at threshold, maximal arm power and competitive results (P < 0.05). The authors conclude that more high-intensity volume "may improve" results in skiers who fail to respond to more low-intensity volume. Our reading: an observation behind "if the stimulus stops working, change it", and a hopeful one, but it is weak.

People picked for a poor year will tend to improve the next year on any plan. The abstract does not report the control group's change or a test against it.

Protocol

Year one: n = 14 skiers, standard programme of high volume and low intensity; tests of VO2max, VO2 at threshold, lactate response, maximal arm power, competitive results.
Year two: control (N = 7, responded well) repeated the programme; treatment (N = 7, responded poorly) raised high-intensity training from under 17% to over 35% of time and cut low-intensity volume by 22%.
Not in the abstract: the definition of high intensity, how "responded" was defined, sex split (PubMed's indexing lists both men and women), hours of training, magnitudes of change, control results.
Funding and interests: none stated in the PubMed or Crossref record.

Key Results

Outcome in year twoTreatment (poor responders, N = 7)Control (good responders, N = 7)Between groups
VO2maxsignificantly improved (P < 0.05)not givennot given
VO2 at thresholdsignificantly improved (P < 0.05)not givennot given
Maximal arm powersignificantly improved (P < 0.05)not givennot given
Competitive resultssignificantly improved (P < 0.05)not givennot given
Individual response: groups are defined by it, but no individual data or measurement error are given.

Mechanisms

Measured: within-group improvement among poor responders after shifting to more high-intensity time.
Authors' interpretation: more high-intensity volume may help skiers who did not respond to more low-intensity volume.
Inference: regression to the mean, a year of added fitness or maturation, and the change in intensity are not separable in this design.

Practical Application

Will athletes who stall on easy volume respond to more intensity? 7 poor-responding skiers raised high-intensity share (under 17% to over 35%) and improved. Picked for a poor year, not randomised: may be rebound. Abstract only.
How to use it: a plausible reason to try another stimulus after a stall, not evidence that the switch caused the gain. Not from this paper; the base's own practice: one lever per block and read the outcome (SYNTH-42, C+). More controlled work on the same idea: REF-989 (A-) for adding work above the steady-state ceiling.
What it does not show: that stalled athletes need intensity rather than more dose, rest or fuel; any size of effect; that sub-threshold plans stall in the same way. It tests no sweet-spot format.

Limitations

Non-randomised, selected on response; regression to the mean is the main rival explanation.
Abstract only; no magnitudes, no control results, no between-group statistics.
Very small; 7 per group, one sport.
Two consecutive years; no concurrent comparator with poor responders left on the old plan.
High intensity undefined in the abstract.
Funding and interests: not stated in the record.
How this entry was checked and changed
Why this level

(from the abstract) — a small non-randomised study (rubric B) with limits beyond design: selection on the outcome (poor responders) invites regression to the mean, and an abstract-only small study has key methods and all effect sizes missing