@article{3015519, title = "Assessment of ventilatory threshold using near-infrared spectroscopy on the gastrocnemius muscle during treadmill running", author = "Karatzanos, E. and Paradisis, G. and Zacharogiannis, E. and Tziortzis, S. and Nanas, S.", journal = "International Journal of Industrial Ergonomics", year = "2010", volume = "40", number = "2", pages = "206-211", issn = "0169-8141", doi = "10.1016/j.ergon.2009.02.003", keywords = "Anaerobic thresholds; Exercise training; Gastrocnemius muscle; Heart rates; Human performance assessment; Incremental exercise; Initial speed; Linear model; Occupational health; Simulated environment; Time duration; Tissue oxygen saturation; Ventilatory thresholds, Industrial hygiene; Infrared devices; Infrared spectroscopy; Infrared transmission; Oxygen; Oxygenation; Oxygenators; Sporting goods; Textiles; Velocity, Muscle, adult; article; controlled study; exercise test; exhaustion; female; gastrocnemius muscle; heart rate; human; human experiment; lung capacity; male; muscle metabolism; near infrared spectroscopy; normal human; oxygen saturation; priority journal; treadmill exercise", abstract = "This study was designed to investigate the efficacy of the near-infrared spectroscopy (NIRS) methodology in exploring the relationship between ventilatory (VT) and NIRS-determined threshold on the gastrocnemius muscle during running. Seventeen healthy participants, 11 males and 6 females performed an incremental exercise test until volitional exhaustion on a treadmill. Initial speed was set at 8 km/h with increments of 0.5 km/h per minute. Tissue oxygen saturation (StO2) was obtained from the belly of the left gastrocnemius muscle. Running velocity at the NIRS threshold was evaluated with StO2-velocity plots, employing two different models: linear (NTlin) and Dmax (NTD). Significant difference in velocity was observed between NTD (11.7 ± 0.9 km/h) and VT (11.2 ± 1.2 km/h). However, no difference in velocity was observed between VT and NTlin (11.6 ± 0.8 km/h, p > 0.05), and between the two NIRS methods (p > 0.05). VT velocity was significantly correlated (p < 0.05) to NTlin (r = 0.86) and NTD (r = 0.84). Time duration at NIRS threshold as assessed with StO2-time plots employing a linear model (NT), did not differ from VT (8.5 ± 1.8 min vs. 7.9 ± 2.5 min respectively, p > 0.05). Furthermore, small but significant differences (p < 0.05) were found between VO2 and heart rate at VT and NT, expressed in either relative or maximum percentage values. Both NIRS-derived models were well correlated with VT and did not differ from each other. NIRS methodology applied on the gastrocnemius muscle was found to provide a useful means of detecting VT during treadmill running and to be practically appropriate in prescribing exercise training in running. Relevance to industry: Human performance assessment is useful in the field of occupational health or industry. Ventilatory threshold along with NIRS methodology could be used in the field or a simulated environment to evaluate performance of professionals involved in physically demanding activities, such as firefighting and construction. © 2009 Elsevier B.V. All rights reserved." }