PURPOSE: To investigate the cardiorespiratory and metabolic response of trail running and evaluate whether heart rate (HR) adequately reflects the exercise intensity or if the tissue-saturation index (TSI) could provide a more accurate measure during running in hilly terrain. METHODS: Seventeen competitive runners (4 women, V̇O2max, 55 ± 6 mL · kg-1 · min-1; 13 men, V̇O2max, 68 ± 6 mL · kg-1 · min-1) performed a time trial on an off-road trail course. The course was made up of 2 laps covering a total distance of 7 km and included 6 steep uphill and downhill sections with an elevation gain of 486 m. All runners were equipped with a portable breath-by-breath gas analyzer, HR belt, global positioning system receiver, and near-infrared spectroscopy (NIRS) device to measure the TSI. RESULTS: During the trail run, the exercise intensity in the uphill and downhill sections was 94% ± 2% and 91% ± 3% of maximal heart rate, respectively, and 84% ± 8% and 68% ± 7% of V̇O2max, respectively. The oxygen uptake (V̇O2) increased in the uphill sections and decreased in the downhill sections (P < .01). Although HR was unaffected by the altering slope conditions, the TSI was inversely correlated to the changes in V̇O2 (r = -.70, P < .05). CONCLUSIONS: HR was unaffected by the continuously changing exercise intensity; however, TSI reflected the alternations in V̇O2. Recently used exclusively for scientific purposes, this NIRS-based variable may offer a more accurate alternative than HR to monitor running intensity in the future, especially for training and competition in hilly terrain.
PURPOSE: To investigate the cardiorespiratory and metabolic response of trail running and evaluate whether heart rate (HR) adequately reflects the exercise intensity or if the tissue-saturation index (TSI) could provide a more accurate measure during running in hilly terrain. METHODS: Seventeen competitive runners (4 women, V̇O2max, 55 ± 6 mL · kg-1 · min-1; 13 men, V̇O2max, 68 ± 6 mL · kg-1 · min-1) performed a time trial on an off-road trail course. The course was made up of 2 laps covering a total distance of 7 km and included 6 steep uphill and downhill sections with an elevation gain of 486 m. All runners were equipped with a portable breath-by-breath gas analyzer, HR belt, global positioning system receiver, and near-infrared spectroscopy (NIRS) device to measure the TSI. RESULTS: During the trail run, the exercise intensity in the uphill and downhill sections was 94% ± 2% and 91% ± 3% of maximal heart rate, respectively, and 84% ± 8% and 68% ± 7% of V̇O2max, respectively. The oxygen uptake (V̇O2) increased in the uphill sections and decreased in the downhill sections (P < .01). Although HR was unaffected by the altering slope conditions, the TSI was inversely correlated to the changes in V̇O2 (r = -.70, P < .05). CONCLUSIONS: HR was unaffected by the continuously changing exercise intensity; however, TSI reflected the alternations in V̇O2. Recently used exclusively for scientific purposes, this NIRS-based variable may offer a more accurate alternative than HR to monitor running intensity in the future, especially for training and competition in hilly terrain.
Authors: Trent E Cayot; Shara G Robinson; Lindsay E Davis; Paul A Bender; John R Thistlethwaite; Craig E Broeder; Jakob D Lauver Journal: Int J Exerc Sci Date: 2021-04-01
Authors: Joana Oliveira-Rosado; João P Duarte; Paulo Sousa-E-Silva; Daniela C Costa; Diogo V Martinho; Hugo Sarmento; João Valente-Dos-Santos; Luís M Rama; Óscar M Tavares; Jorge Conde; Joaquim Castanheira; Rui Soles-Gonçalves; Ricardo R Agostinete; Manuel J Coelho-E-Silva Journal: Einstein (Sao Paulo) Date: 2020-04-06
Authors: Alasdair S Tutt; Hampus Persson; Erik P Andersson; Mats Ainegren; Nikolai Stenfors; Helen G Hanstock Journal: Eur J Appl Physiol Date: 2021-03-29 Impact factor: 3.078
Authors: Francisco Pradas; David Falcón; Carlos Peñarrubia-Lozano; Víctor Toro-Román; Luis Carrasco; Carlos Castellar Journal: Int J Environ Res Public Health Date: 2021-05-12 Impact factor: 3.390