Vo2max in overweight and obese adults: do they meet the threshold criteria?
OBJECTIVE
The purpose of this study was to determine whether adiposity affects the attainment of (.)VO2max.


METHODS
Sixty-seven male and 68 female overweight (body mass index (BMI) = 25-29.9 kg.m) and obese (BMI > or = 30 kg x m) participants undertook a graded treadmill test to volitional exhaustion (phase 1) followed by a verification test (phase 2) to determine the proportion who could achieve a plateau in (.)VO2 and other "maximal" markers (RER, lactate, HR, RPE).


RESULTS
At the end of phase 1, 46% of the participants reached a plateau in (.)VO2, 83% increased HR to within 11 beats of age-predicted maximum, 89% reached an RER of > or = 1.15, 70% reached a blood lactate concentration of > or = 8 mmol x L, and 74% reached an RPE of > or = 18. No significant differences between genders and between BMI groups were found with the exception of blood lactate concentration (males = 84% vs females = 56%, P < 0.05). Neither gender nor fatness predicted the number of other markers attained, and attainment of other markers did not differentiate whether a (.)VO2 plateau was achieved. The verification test (phase 2) revealed that an additional 52 individuals (39%) who did not exhibit a plateau in (.)VO2 in phase 1 had no further increase in (.)VO2 in phase 2 despite an increase in workload.


CONCLUSIONS
These findings indicate that the absence of a plateau in (.)VO2 alone is not indicative of a failure to reach a true maximal (.)VO2 and that individuals with excessive body fat are no less likely than "normal-weight" individuals to exhibit a plateau in (.)VO2 provided that the protocol is appropriate and encouragement to exercise to maximal exertion is provided.
Wood
Rachel E
RE
School of Human Movement Studies and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. re.wood@qut.edu.au
Hills
Andrew P
AP
Hunter
Gary R
GR
King
Neil A
NA
Byrne
Nuala M
NM
D050154:Adiposity / Q000502:physiology; D000328:Adult; D015992:Body Mass Index; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity; D050177:Overweight; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012119:Respiration; D012129:Respiratory Function Tests / Q000379:methods