RT Journal Article T1 Physiological and biomechanical responses to walking underwater on a non-motorised treadmill: effects of different exercise intensities and depths in middle-aged healthy women. A1 Benelli, Piero A1 Colasanti, Franca A1 Ditroilo, Massimiliano A1 Cuesta-Vargas, Antonio A1 Gatta, Giorgio A1 Giacomini, Francesco A1 Lucertini, Francesco K1 Hidroterapia AB Non-motorised underwater treadmills are commonly used in fitness activities. However, no studies have examined physiological and biomechanical responses of walking on non-motorised treadmills at different intensities and depths. Fifteen middle-aged healthy women underwent two underwater walking tests at two different depths, immersed either up to the xiphoid process (deep water) or the iliac crest (shallow water), at 100, 110, 120, 130 step-per-minute (spm). Oxygen consumption (VO2), heart rate (HR), blood lactate concentration, perceived exertion and step length were determined. Compared to deep water, walking in shallow water exhibited, at all intensities, significantly higher VO2 (+13.5%, on average) and HR (+8.1%, on average) responses. Water depth did not influence lactate concentration, whereas perceived exertion was higher in shallow compared to deep water, solely at 120 (+40%) and 130 (+39.4%) spm. Average step length was reduced as the intensity increased (from 100 to 130 spm), irrespective of water depth. Expressed as a percentage of maximum, average VO2 and HR were: 64-76% of peak VO2 and 71-90% of maximum HR, respectively at both water depths. Accordingly, this form of exercise can be included in the "vigorous" range of exercise intensity, at any of the step frequencies used in this study. PB Taylor & Francis YR 2014 FD 2014 LK https://hdl.handle.net/10630/37890 UL https://hdl.handle.net/10630/37890 LA eng NO Benelli P, Colasanti F, Ditroilo M, Cuesta-Vargas A, Gatta G, Giacomini F, Lucertini F. Physiological and biomechanical responses to walking underwater on a non-motorised treadmill: effects of different exercise intensities and depths in middle-aged healthy women. J Sports Sci. 2014;32(3):268-77. doi: 10.1080/02640414.2013.824601. Epub 2013 Sep 9. PMID: 24015764. NO https://openpolicyfinder.jisc.ac.uk/id/publication/5753 DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 12 abr 2026