Evaluation of the Best-designed Graded Exercise Test to Assess Peak Treadmill Speed.

This study examined the influence of different speed increments during treadmill exercise tests on peak treadmill speed (Vpeak) and its relationship with a 1-h treadmill running performance. 18 male recreational and amateur runners (10-km running pace: 10-15 km·h(-1)) performed, in an alternate order, 3 continuous incremental exercise tests with different speed increments (0.5, 1.0 and 2.0 km·h(-1)) on a motorized treadmill to determine Vpeak. Thereafter they undertook a 1-h time trial on a treadmill. Vpeak was determined as either (a) the highest speed that could be maintained for a complete minute (Vpeak-60 s), (b) the speed of the last complete stage (Vpeak-C), or (c) the speed of the last complete stage added to the product of the speed increment and the completed fraction of the incomplete stage (Vpeak-P). The Vpeak values were highly influenced by the different speed-incremented rates and the Vpeak-P determined during the protocol comprising speed increments of 1 km·h(-1) presented the highest correlation with 1-h time trial performance (r=0.89). The results suggest that a protocol with speed increments comprising 1 km·h(-1) and with a 3-min stage duration should be used as standard for the determination of Vpeak to assess aerobic fitness and predict endurance performance in recreational runners. Furthermore, the Vpeak-P should be used for the determination of Vpeak.

Relationship between heart rate deflection point determined by Dmax method and 10-km running performance in endurance recreationally-trained female runners.

AIM: The aim of this paper was to verify the relationship between the speed at heart rate deflection point based on Dmax method (sHRDPDmax) with 10-km running performance and the speed at lactate threshold calculated with Dmax method (sLTDmax) in endurance recreationally-trained female runners. We also aim to examine the influence of exponential-plus-constant and third-order polynomial regression models and the influence of the heart rate points (model with initial HR points above 140 b·min(-1) versus model with all HR points) on the determination of the sHRDPDmax. METHODS: Thirteen endurance recreationally-trained female runners were recruited. Participants performed a discontinuous incremental exercise tests initiating at 7 km·h(-1) with 1 km·h(-1) increments each 3 min to determine sHRDPDmax and sLTDmax according to two adjustments: 1) exponential-plus-constant regression model (sHRDPexp and sLTexp); 2) third-order polynomial regression model (sHRDPpol and sLTpol). The sHRDPDmax was also calculated based on HR points above 140 b·min(-1) (sHRDPexp>140 and sHRDPpol>140). Each participant performed a 10-km running performance (s10km). RESULTS: Only the sHRDPexp and sHRDPexp>140 correlated with s10km (sHRDPexp, r=0.87; sHRDPexp>140, r=0.76) and showed higher correlations than the sHRDPpol and sHRDPpol>140 with sLTDmax. The sHRDPexp presented higher correlation with sLTexp than sHRDPexp>140, however sHRDPexp>140 better correlated with sLTpol than sHRDPexp. Furthermore, sHRDPpol>140 demonstrated higher correlations with sLTexp and sLTpol than sHRDPpol. CONCLUSION: The determination of sHRDPDmax according to different initial HR point and its correlation with sLTDmax is influenced by the regression model. Further, only sHRDPexp and sHRDPexp>140 were predictors of endurance performance. However, despite the high correlations, the deflection point very often occurred around the midpoint between initial and final speeds during the incremental test suggesting that the exponential-plus-constant may not be an appropriate regression curve.

The Dmax is highly related to performance in middle-aged females.

The present study examined whether the running speed at the lactate threshold estimated by the maximal deviation method (LT (Dmax)) is highly correlated and in agreement with 10-km road race performance (S (10 km)) in middle-aged female runners. Additionally, the LT (Dmax) was compared with the visual detection of the inflection point (LT (Visual)), the fixed lactate level of 4 mmol.L (-1) (LT (4)) and the peak speed (S (peak)) in relation to performance. Sixteen middle-aged, recreational female runners performed a discontinuous, incremental treadmill test. The initial speed was set at 7 km.h (-1), and this speed was increased every 3 min by 1 km.h (-1) with a 30-s rest between the stages used for earlobe capillary blood sample collection. All of the participants took part in the same local 10-km road race, and S (10 km) mean speed was calculated. The speeds (mean ± SD) were 10.5 ± 1.0 (S (10 km)), 10.5 ± 1.0 (LT (Visual)), 10.9 ± 0.9 (LT (Dmax)), 11.4 ± 1.3 (LT (4)) and 13.5 ± 1.1 km.h (-1) (S (peak)). The LT (Dmax) had the narrowest limits of agreement (0.3 ± 0.4 km.h (-1)) and was the most highly correlated with the S (10 km) ( R=0.98), followed by the S (peak) ( R=0.95), LT (4) ( R=0.85) and LT (Visual) ( R=0.81). In conclusion, the LT (Dmax) should be more widely used to estimate long-distance performance and to verify improvements in training.