Dd. Frangolias et Ec. Rhodes, MAXIMAL AND VENTILATORY THRESHOLD RESPONSES TO TREADMILL AND WATER IMMERSION RUNNING, Medicine and science in sports and exercise, 27(7), 1995, pp. 1007-1013
This study compared the metabolic responses of 13 endurance runners, f
amiliar with nonweight-bearing water immersion (WI) running, at ventil
atory threshold (T-vent) and maximal effort (V over dot O-2max) for bo
th treadmill and WI running performance. Oxygen consumption (V over do
t O-2), ventilation (V over dot (E)), heart-rare (HR), V over dot (E)/
V over dot O-2, respiratory exchange ratio (RER), perceived exertion (
RPE), and stride frequency (SF) were measured at T-vent and V over dot
O-2max. Paired t-tests revealed higher V over dot O-2max (59.7 vs 54.
6 ml . kg .(-1)min(-1)), HR(max) (190 vs 175 bpm), RER(max) (1.20 vs 1
.10), V over dot O-2 at T-vent (46.3 vs 42.8 ml . kg .(-1)min(-1)), HR
at T-vent (165 vs 152 bpm) for treadmill versus WI running, respectiv
ely. Treadmill and WI V over dot (Emax) (109.0 vs 105.8 1 . min(-1)),
RPE(max) (20), V over dot (E) at T-vent (66.4 vs 65.7 1 . min(-1)), RE
R at T-vent (0.99 vs 0.98), RPE at T-vent (13 vs 12) were similar, as
were blood lactate [BLa] values obtained at 30 s (10.4 vs 9.8 mmol . l
(-1)) and 5 min (9.7 vs 9.2 mmol . l(-1)) post-test. SF values over ti
me were higher on the treadmill. The lower WI V over dot O-2max with s
imilar peak [BLa] and lower SF values suggests that the active muscula
ture and muscle recruitment patterns differ in WI running due to the h
igh viscosity friction of water, and the nonweight-bearing nature of W
I running.