Incremental Test Protocol, Recovery Mode and the Individual Anaerobic Threshold

Abstract

The individual anaerobic threshold (IAT) is defined as the highest metabolic rate at which blood lactate (LA) concentrations are maintained at a steady-state during prolonged exercise (15). The purpose of this study was to compare the effects of active and passive recovery on the determination of IAT following both a submaximal or maximal incremental exercise test. Seven males (V̇O₂max = 57.6±5.8 ml·kg^-1 ·min ^-1 did two submaximal, incremental cycle exercise tests (30 W and 4 min per step) and two maximal incremental tests. Blood was sampled repeatedly during exercise and for 12 min during the subsequent recovery period, which was passive for one submaximal and one maximal test and active(˜ 35% V̇O₂max) during the other tests. An IAT metabolic rate and power output were caclulated for the submax-passive (IAT_sp, LA =1.85±0.42 mmol·1·^-1), maxpassive (IAT_mp, LA = 3.41±1.14 mmol·1^-1), submax-active (IAT_sa, LA = 2.13±0.45 mmol·1^-1) and max-active (IAT_ma, LA = 3.44 ± 0.73 mmol·1^-1) protocols. At weekly intervals, the subjects exercised for 30 min at one of the four IAT metabolic rates. Active recovery did not affect the calculation of IAT, but following the maximal incremental tests, IAT occurred at a higher (p < 0.05) power output, absolute V̇O₂ and %V̇₂max (71% V̇O₂max) compared with the IAT determined with the submaximal incremental tests (61% V̇O₂max). During the 30-min IAT_mp and IAT_ma rides, LA and pH did not change significantly during the final 15 min, but LA values were higher (4.65±0.62 and 5.20±1.30, respectively) and pH lower (7.31±0.02 and 7.30±0.06, respectively) compared with the IAT_sp and IAT_sa rides (2.40±0.77 and 2.90±0.78, respectively for LA and 7.36±0.03 and 7.35±0.03, respectively for pH). The results demonstrate that for these subjects the calculated IAT is not affected by an active recovery period but the IAT occurred at a higher metabolic rate following a maximal compared with a submaximal incremental exercise test.

Key words

Blood lactate - exercise - metabolism - steady-state