title: Critical power in adolescents: physiological bases and assessment using all-out exercise.
abstract: This study examined whether critical power (CP) in adolescents: (1) provides a landmark for maximal steady-state exercise; and (2) can be determined using 'all-out' exercise. Nine active 14-15 year olds (6 females, 3 males) performed five cycling tests: (1) a ramp test to determine VO(2peak); (2) up to four constant power output tests to determine CP; (3-4) constant power output exercise 10% above and 10% below CP; and (5) a 3 min all-out cycle test to establish the end power (EP) at 90 and 180 s of exercise. All participants completed 30 min of exercise below CP and were characterized by steady-state blood lactate and VO(2) profiles. In contrast, time to exhaustion during exercise above CP was 15.0 ± 7.0 min and characterized by an inexorable rise in blood lactate and a rise, stabilization (~91% VO(2peak)) and fall in VO(2) (~82% VO(2peak)) prior to exhaustion. Eight out of nine participants completed the 3 min test and their EPs at 90 s (148 ± 29 W) and 180 s (146 ± 30 W) were not different from CP (146 ± 27 W) (P = 0.98). The typical error of estimates for establishing CP using EP at 90 s or 180 s of the 3 min test were 25 W (19.7% CV) and 25 W (19.6% CV), respectively. CP in active adolescence provides a valid landmark for maximal steady-state exercise, although its estimation on an individual level using the 3 min all-out test may be of limited value. VO(2peak)
authors.affiliation: Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter EX1 2LU, UK. A.R.Barker@exeter.ac.uk
authors.forename: Alan R
authors.initials: AR
authors.lastname: Barker
authors.forename: Bert
authors.initials: B
authors.lastname: Bond
authors.forename: Cali
authors.initials: C
authors.lastname: Toman
authors.forename: Craig A
authors.initials: CA
authors.lastname: Williams
authors.forename: Neil
authors.initials: N
authors.lastname: Armstrong
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D004739:England; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D013997:Time Factors
chemical_list: D015415:Biomarkers; D019344:Lactic Acid