Details

Autor(en) / Beteiligte

• CAEN, KEVIN
• VERMEIRE, KOBE
• BOURGOIS, JAN G
• BOONE, JAN

Titel

Exercise Thresholds on Trial: Are They Really Equivalent?

Ist Teil von

• Medicine and science in sports and exercise, 2018-06, Vol.50 (6), p.1277-1284

Ort / Verlag

United States: American College of Sports Medicine

Erscheinungsjahr

2018

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• PURPOSEThe interchangeable use of whole-body exercise thresholds and breakpoints (BP) in the local oxygenation response, as measured via near-infrared spectroscopy, has recently been questioned in scientific literature. Therefore, the present study aimed to longitudinally investigate the interrelationship of four commonly used exercise thresholdscritical power (CP), the respiratory compensation point (RCP), and BP in muscle (m[HHb]BP) and brain (c[O2Hb]BP) oxygenation. METHODSNine male participants (21.8 ± 1.2 yr) completed 6 wk of cycling interval training. Before and after this intervention period, subjects performed a ramp incremental exercise protocol to determine RCP, m[HHb]BP, and c[O2Hb]BP and four constant work rate (WR) tests to calculate CP. RESULTSWR associated with CP, RCP, m[HHB]BP, and c[O2Hb]BP increased by 7.7% ± 4.2%, 13.6% ± 9.0%, 9.8% ± 5.7%, and 11.3% ± 11.1%, respectively. CP was lower (pre260 ± 32 W, post280 ± 41 W; P < 0.05) than the WR associated with RCP (pre281 ± 28 W, post318 ± 36 W) and c[O2Hb]BP (pre283 ± 36 W, post313 ± 32 W) which occurred concomitantly (P = 0.683). M[HHb]BP occurred at the highest WR and differed from all others (pre313 ± 23 W, post344 ± 32 W; P < 0.05). Training-induced WR differences (ΔWR) did not contrast between thresholds, and initial parameter differences were not affected by the intervention (P = 0.253). Thresholds were partly correlated before (R = 0.67–0.85, P < 0.05) and after (R = 0.83–0.96, P < 0.05) training, but ΔWR values were not associated (P > 0.05). CONCLUSIONSResults of the present study strongly question true equivalence of CP, RCP, m[HHb]BP, and c[O2Hb]BP during ramp incremental exercise. Therefore, these exercise thresholds should not be used interchangeably.