compression tights. Overview Participants reported to the laboratory on 3 separate occasions. The first session was a familiarization trial of the RSE protocol, in which participants performed 2 sets of sprints with the near-infrared spectroscopy (NIRS) and metabolic equipment. During this session
James R. Broatch, David J. Bishop and Shona Halson
Nicola Giovanelli, Lea Biasutti, Desy Salvadego, Hailu K. Alemayehu, Bruno Grassi and Stefano Lazzer
activities. For example, near-infrared spectroscopy (NIRS) allows to evaluate the tissue oxygenation dynamics under different conditions. 7 In particular, during the past few years, different authors used NIRS to evaluate exercise intensity and muscle oxygenation dynamics in different sport situations. 8
Simon Fryer, Craig Paterson, Ian C. Perkins, Chris Gloster, Mark E.T. Willems and Julia A. Potter
active recovery. In order to allow recovery from the three phase activities and MVC trials, the near infrared spectroscopy (NIRS) equipment was fitted after the MVCs within approximately 10 min. In brief, participants were fitted with a continuous wave near-infrared spectroscopy device (cw-NIRS), with
Dennis-Peter Born, Christoph Zinner, Britta Herlitz, Katharina Richter, Hans-Christer Holmberg and Billy Sperlich
The current investigation assessed tissue oxygenation and local blood volume in both vastus lateralis muscles during 3000-m race simulations in elite speed skaters on ice and the effects of leg compression on physiological, perceptual, and performance measures.
Ten (6 female) elite ice speed skaters completed 2 on-ice trials with and without leg compression. Tissue oxygenation and local blood volume in both vastus lateralis muscles were assessed with near-infrared spectroscopy. Continuous measures of oxygen uptake, ventilation, heart rate, and velocity were conducted throughout the race simulations, as well as blood lactate concentration and ratings of perceived exertion before and after the trials. In addition, lap times were assessed.
The investigation of tissue oxygenation in both vastus lateralis muscles revealed an asymmetry (P < .00; effect size = 1.81) throughout the 3000-m race simulation. The application of leg compression did not affect oxygenation asymmetry (smallest P = .99; largest effect size = 0.31) or local blood volume (P = .33; 0.95). Lap times (P = .88; 0.43), velocity (P = .24; 0.84), oxygen uptake (P = .79; 0.10), ventilation (P = .11; 0.59), heart rate (P = .21; 0.89), blood lactate concentration (P = .82; 0.59), and ratings of perceived exertion (P = .19; 1.01) were also unaffected by the different types of clothing.
Elite ice speed skaters show an asymmetry in tissue oxygenation of both vastus lateralis muscles during 3000-m events remaining during the long gliding phases along the straight sections of the track. Based on the data, the authors conclude that there are no performance-enhancing benefits from wearing leg compression under a normal racing suit.
Michael Bar-Eli, Arie Shirom, Michal Nir and Ayala Malach Pines
Ninety female athletes at the international and/or national level, engaged in sports that are either “feminine” (n=49) or “non-feminine” (n=41), participated in this study. We predicted (a) a positive relation between role conflict and burnout; and (b) higher role conflict and burnout among athletes from “non-feminine” sports. Questionnaire results revealed a positive relation between role conflict and burnout, albeit only in “feminine” sports. Role conflict was not higher among athletes from “non-feminine” sports. Burnout was somewhat lower among “non-feminine”-sports athletes. “Feminine”-sports athletes were significantly younger, had more training, and felt more restricted by their athletic activity, in comparison to “non-feminine”-sports athletes. Results are interpreted in terms of current theoretical perspectives, such as the “expansionist” approach.
Philippe Richard and François Billaut
isometric gliding phase, and high intramuscular forces results in impeded blood flow to working muscles. 1 Near-infrared spectroscopy (NIRS) studies further demonstrated that a low skating position during in-line speed skating is associated with an accentuated deoxygenation compared with an upper skating
Near-infrared spectroscopy (NIRS) presents an appealing option for investigating hemodynamic changes in the cerebral cortex during exercise. This review examines the physical basis of NIRS and the types of available instruments. Emphasis is placed on the physiological interpretation of NIRS signals. Theories from affective neuroscience and exercise psychobiology, including Davidson's prefrontal asymmetry hypothesis, Dietrich's transient hypofrontality hypothesis, and Ekkekakis's dual-mode model, are reviewed, highlighting the potential for designing NIRS-based tests in the context of exercise. Findings from 28 studies involving acute bouts of exercise are summarized. These studies suggest that the oxygenation of the prefrontal cortex increases during mild-to-moderate exercise and decreases during strenuous exercise, possibly proximally to the respiratory compensation threshold. Future studies designed to test hypotheses informed by psychological theories should help elucidate the significance of these changes for such important concepts as cognition, affect, exertion, and central fatigue.
Vivian H. Heyward, Kelly L. Cook, Virginia L. Hicks, Kathy A. Jenkins, Joseph A. Quatrochi and Wendy L. Wilson
Three methods of body composition assessment were used to estimate percent body fat (%BF) in nonobese (n=77) and obese (n=71) women, 20-72 yrs of age, Skinfolds (SKF), bioelectrical impedance (BIA), and near-infrared interactance (NIR) methods were compared to criterion-derived %BF from hydrostatic weighing (%BFHW). Nonobese subjects had < 30%
Tibor Hortobágyi, Richard G. Israel, Joseph A. Houmard, Kevin F. O'Brien, Robert A. Johns and Jennifer M. Wells
Four methods of assessing body composition were compared in 55 black and 35 white, Division 1, American football players. Percent body fat (%BF) was estimated with hydrostatic weighing at residual volume, corrected for race; seven-site skinfolds (7 SF), corrected for race; bioelectrical impedance analysis (BIA); and near-infrared spectrophotometry (NIR). Percent body fat with HW in blacks (mean = 14.7%) and whites (19.7%) did not differ (P > .05) from %>BF with 7 SF (blacks, 14.7%; whites, 19.0%). In relation to HW, BIA significantly (P < .05) overpredicted (blacks: 20.1%, SEE = 3.2%; whites; 22.3%, SEE = 4.3%) and NiR underpredicted %BF (blacks; 12.6%, SEE = 3.9%; whites; 17.7%, SEE = 3.6%). The contribution of BIA variables (resistance, phase angle, conductance) and NIR optical density to predict %BF was trivial compared to body mass index. It appears that race may not substantially influence %BF prediction by NIR and BIA. It was concluded that when considering the cost and expertise required with NIR and BIA, SF measurements appear to be a superior alternative for rapid and accurate body composition assessment of athletes, independent of race.
Y.L. Lo, H.H. Zhang, C.C. Wang, Z.Y. Chin, S. Fook-Chong, C. Gabriel and C.T. Guan
In overt reading and singing tasks, actual vocalization of words in a rhythmic fashion is performed. During execution of these tasks, the role of underlying vascular processes in relation to cortical excitability changes in a spatial manner is uncertain. Our objective was to investigate cortical excitability changes during reading and singing with transcranial magnetic stimulation (TMS), as well as vascular changes with nearinfrared spectroscopy (NIRS). Findings with TMS and NIRS were correlated. TMS and NIRS recordings were performed in 5 normal subjects while they performed reading and singing tasks separately. TMS was applied over the left motor cortex at 9 positions 2.5 cm apart. NIRS recordings were made over these identical positions. Although both TMS and NIRS showed significant mean cortical excitability and hemodynamic changes from baseline during vocalization tasks, there was no significant spatial correlation of these changes evaluated with the 2 techniques over the left motor cortex. Our findings suggest that increased left-sided cortical excitability from overt vocalization tasks in the corresponding “hand area” were the result of “functional connectivity,” rather than an underlying “vascular overflow mechanism” from the adjacent speech processing or face/mouth areas. Our findings also imply that functional neurophysiological and vascular methods may evaluate separate underlying processes, although subjects performed identical vocalization tasks. Future research combining similar methodologies should embrace this aspect and harness their separate capabilities.