The difference in VO2max between lab and field testing in highly trained cyclists

Maximum oxygen consumption (VO2max), is considered the gold standard measure for aerobic
endurance and a key performance predictor for endurance sports such as cycling. Defined as
“the highest rate at which oxygen can be taken up and utilised by the body during severe
exercise” (Bassett and Howley, 2000, Medicine and Science in Sports and Exercise, 32, 70-
84), VO2max is usually measured through laboratory testing on an ergometer. These tests are
designed to last around 8-12 minutes, consisting of an open-ended increase in intensity until
the subject reaches volitional exhaustion. Issues with traditional VO2max testing include an
inability to regulate intensity due to fixed resistance and a lack of conscious decision making
during the test (Noakes, 2008, British Journal of Sports Medicine, 42, 551-555). To investigate
we examined whether a cycling hill climb designed to last 8-12 minutes would result in a higher
VO2max value than that of a lab-based test. Ethical approval was granted by Teesside
University ethics committee. Ten highly-trained cyclists mean ± SD age 28.6 ± 11.3 years,
height 182.4 ± 6.9 cm, mass 75.5 ± 11.6 kg performed a 20 W/minute cycle ergometer ramp
test and a 3.2km hill-climb on their own bike wearing a portable gas analyser in a randomised,
counterbalanced order. Statistical analyses using a paired t-test showed that the hill climb
resulted in a significantly higher relative VO2max (lab 67.9 ± 8.4 ml.kg-1.min-1, vs. field 70.2 ± 8.9
ml.kg-1.min-1
, P = 0.002; absolute VO2max: lab 5.05 ± 0.9 ml.kg-1.min-1, vs. field 5.18 ± 0.9 ml.kg-
1.min-1
, P = 0.039). Secondary VO2max criteria, RERmax (lab 1.09 ± 0.1, vs. field 1.20 ± 0.1, P =
0.013) and 5-minute-post blood lactate (lab 8.04 ± 1.6 mmol.l-1, vs. field 12.46 ± 1.5 mmol.l-1
,
P < 0.001) were significantly higher during field testing. There were no significant differences
in HRmax (lab 188 ± 11 beats.min-1, vs. field 188 ± 9.9 beats.min-1
, P = 0.695) or end lactate
(lab 9.74 ± 1.2 mmol.l-1, vs. field 12.43 ± 2.4 mmol.l-1
, P = 0.130). Higher VO2max values
recorded during the field test may be explained by the closed-loop format allowing better
pacing, the cooling effect of the wind outdoors, out-the-saddle riding permitted leading to
greater muscle recruitment and the sub-optimal length of the lab test 20.5 ± 3.4 min vs. 8.5 ±
1.2 min for the field test. Findings suggest that the increased ecological validity of field-based
testing led to higher VO2max values and may be considered a viable alternative to lab-based
testing.