Jp. Neary et al., VALIDITY OF BREATHING FREQUENCY TO MONITOR EXERCISE INTENSITY IN TRAINED CYCLISTS, International journal of sports medicine, 16(4), 1995, pp. 255-259
This study compared breathing frequency (f(B)) during a ventilation th
reshold (VT) test with f(B) during a simulated 40 km time trial (40TT)
to assess whether f(B) can be used to monitor exercise intensity. Twe
nty-six male cyclists (X+/-SD VO(2)max = 4.42+/-0274 l . min(-1)) perf
ormed an incremental VT ergometer test and a simulated 40TT on a set o
f wind-loaded rollers. During the 40TT, expired gas was collected for
3 min using open circuit spirometry at 10 km intervals. A significant
correlation (r = 0.89; p less than or equal to 0.05) was found between
the f(B) threshold (VTf) and the gas exchange VT (VTg) (3.42+/-0.08 a
nd 3.31+/-0.09 l . min(-1), respectively). No differences were found i
n VO2 at the VTf vs. X VO2 (3.48+/-0.08 l . min(-1)) during the simula
ted 40TT. However, when f(B) in br . min(-1) calculated from the VT te
st (32.5 br . min(-1)), was compared with f(B) during the 40TT (45.6 b
r . min(-1)), there was a significant difference. Ventilation, heart r
ate and the respiratory exchange ratio were all significantly higher d
uring the 40TT. Although a significant relationship was found between
the VT test and the 40TT for VTf measured in l . min(-1) of VO2 (r = 0
.66; p less than or equal to 0.05), f(B) in br . min(-1) obtained from
the incremental test should not be used to identify exercise training
intensity. These data suggest that during competition, trained athlet
es exercise at a higher f(B) than that determined when being tested, i
mplying that f(B) in br . min(-1) may not be a Valid measurement of ex
ercise intensity.