English abstract
The current study aimed to investigate the effect of knowing the end point of
running tasks (distance or duration) on performance, physiological variables (heart
rate: HR, rate of perceived exertion: RPE), and pacing strategy during a self-paced
running trial. Twenty four physical education and sports sciences students
participated in this study (age: 21±1.1 years, height: 172.5±5.6 cm, body mass:
66.2±7.0 kg, body mass index: 21.9±2.4 kg/m²). All participants performed a
multistage incremental test to determine maximal aerobic speed (MAS) and
continuous running exercises at MAS up to exhaustion (constant speed test) in order
to determine the total distance covered and total duration of the test (tlim at MAS);
they then individually and randomly performed two self paced running exercises,
where the end point was determined as distance (distance test) and duration (duration
test) that were determined during the tlim test. Heart HR and RPE were recorded
during all tests. Speed and HR were recorded at every 10% of the total distance
covered during the two self paced running tests. RPE was also obtained at the middle
and the end of the two self paced running tests. Results showed that covered distance
was not significantly different (p>0.05) between the constant speed test and the
duration test (1331.4±281 m vs. 296.8±1320.9 m). On the other hand, there were
statistically significant differences (p<0.05) between the time spent on the constant
speed test and the distance test (321.6±69.8 s vs. 295.9±72.3 s). The results also
showed, there were significant differences (p<0.05) in RPE taken in the middle and
end of both the distance and duration tests. Results also showed that there were no
significant differences (p>0.05) in HR between the end of the distance and duration
tests. Inverted J-shaped pacing strategy was followed in the distance test with
tendencies for an end-spurt. In contrast, positive pacing strategy was followed in the
duration test. These results demonstrate that the nature of the end point (spatial or
temporal) could affect pacing strategies and performance during self paced running
tests without any changes in HR and RPE. It seems that participants cope with
distance better than time as end point. These results can provide coaches and strength
and conditioning professionals with relevant information concerning the importance
of varying exercise end point during training programs.
