Can a short-term hiking training speed up V'O2-on kinetic in healthy sedentary women?

We tested the hypothesis that two weeks of training performed at moderate intensity can induce a significant acceleration of the V'02-on kinetics in adultsedentary women. To this aim, breath-by-breath oxygen uptake (V'02) was measured in 8 women (25 yy ± 7; 68 kg ± 11,165 cm ± 8) during: i) an incrementai ramp cycling test up to exhaustion and; ii) during three consecutive square wave tests performed at approximately 50 % of V'02max before and immediately after atraining program of daiiy trekking (6-3 hour/d) performed at near sea level and on irregular and undulating terrain.Absolute and relative V'02max values did not increase as a result of the hiking training. The time Constant of the primary phase (t2: PRE: 23.1 s ± 8; POST 16.4 ± 6) of V02 kinetics were significantly smaller after training (P < 0.05). Percent decrease of t2 was significantly and negativeìy correlated with absolute V'O atbaseline (r = 0.69, P < 0.05). It is concluded that two weeks of training performed at moderate intensity are able to induce a significant acceleration of the dynamicresponse of oxidative metabolism during exercise that is not paralleled by any increase of V'02max in healthy sedentary women. Moreover, the extent of the improvement is affected by the value of V'Omax at the baseline.