xiv
Comparison between the cost of Vo
2
and the cost of heart rate, and the
validation of C
hr
in estimating the velocity of run associated to Vo
2max
in
athletes and non athletes
Parameters of aerobic performance are important for the exercise prescription, however, some
methods used to obtain several parameters, such as ventilatory threshold (VT), lactate
threshold (LT), VO
2
max and Vmax, are expensive and slight available. Accordingly, the
validation of indirect methods to estimate those variables is of great importance. The
estimation of Vmax, through the cost of VO
2
(C
VO2
), can be verified in the literature; yet, it is
still a method which requires few available resources, differently from the cost of heart rate
(C
HR
). Hence, the objectives of the current study were to verify the possibility of estimating
Vmax through the C
HR
, and, consequently, validating a protocol that could answer this
objective. Moreover, the relationship between LT, VT, rating of perceived exertion (RPE),
critical velocity (CV), Vmax and VO
2
were explored. Data were collected from 17 subjects
divided in 2 groups: Group 1 (G1) consisted of 11 subjects physically actives non-athletes
individuals (25,6±5,2 years; 180±9,0 cm; 80,1±11,7 kg; 13,0±5,8 % of body fat and 50,5±3,3
ml.O
2
.kg
-i
.min
-1
). Group 2 (G2) consisted of 6 endurance runners subjects (20,5±2,1 years;
176±12,0 cm; 64,1±11,0 kg; 7,4,0±2,1 % of body fat and 67,6,5±7,9ml.O
2
.kg
-i
.min
-1
). All
subjects were submitted to 5 tests in a treadmill, in alternative days and following a random
order, with exception of the first subject. Before each test, there was a standardized warm-up
(velocity of cost – Vcost), intended to obtain the variables of cost (velocity, VO
2
and HR),
with a 6 minutes duration and intensity based on the RPE (11 a 13 - Borg). The first test was
an incremental (increments of 0,5km.h
-1
every 3 minutes) in treadmill to determine the LT,
VT, VO
2
max e Vmax. The 4 subsequent tests were the predictive sessions to obtain the CV
carried out in relative intensities of 95, 100, 110 e 120% of the Vmax. It was used analysis of
variance for repeated samples and the test t for the paired data, besides the Pearson's
correlation coefficient on the studied variables. The results were divided into study 1 and 2,
corresponding to G1 and G2, respectively. Study 1: the velocities related to Vcusto, LT, VT,
CV and Vmax were respectively: 10,5+0,8, 10,9+0,8, 11,3+1,0, 11,4+1,2 e 13,2+1,1km.h
-1
, of
which, only the CV did not differed from the equivalent velocity of VT. Considering the
analyzed intensities, the consumption of O
2
, the RPE, the [lac] and the HR did not showed
statistical differences in the relative intensities when compared to the LT and VT; though,
there were differences when compared to the relative intensities of Vcost and Vmax, and
these ones with the others. There were no significant differences when comparing the
variables V
max
(real), V
max
(C
HRreal
) and V
max
(C
VO2
), 13,2+1,1, 12,8+1,4 and 13,3+1,8km.h
-1
,
respectively. Study 2: the relative velocities of Vcost, LT, VT and Vmax were, respectively,
15,4+1,1, 16,4+1,1, 16,8+1,2 e 18,2+1,1km.h
-1
, of which, only did not differed the equivalent
velocity of LT from the VT. Considering these analyzed intensities, the consumption of O
2
,
the [lac] and the HR did not show statistical differences on the relative intensities of the LT
and VT; however, they proved to be different in all comparisons with Vmax. The RPE
equivalent to Vcost and Vmax was significantly different from the ones found on the other
intensities. No significant differences were found when the variables V
max
(real), V
max
(C
HRreal
) and V
max
(C
VO2
), respectively18,2+1,2, 17,8+1,6 and 18,2+1,6km.h
-1
were compared.
In conclusion, the utilization of the cost of heart rate, as well the cost of VO
2
, into the
established protocol, was efficient to determine the Vmax. Despite differences (G1) between
the LT and VT velocities, phenomenon like the HR, VO
2
and the RPE did not diverged into
those intensities. The studied variables presented similar behavior, in a relative way, when
comparing physically active non-athletes individuals
with athletes.