Search Results

You are looking at 1 - 4 of 4 items for

  • Author: Benedito S. Denadai x
Clear All Modify Search
Restricted access

Renato A.C. Caritá, Camila C. Greco and Benedito S. Denadai

Prior high-intensity exercise can improve exercise performance during severe-intensity exercise. These positive alterations have been attributed, at least in part, to enhancement of overall oxygen-uptake (VO2) kinetics.

Purpose:

To determine the effects of prior heavy-intensity exercise on VO2 kinetics and short-term high-intensity exercise performance in individuals with different aerobic-training statuses.

Methods:

Fifteen active subjects (UT; VO2max = 43.8 ± 6.3 mL · kg−1 · min−1) and 10 well-trained endurance cyclists (T; VO2max = 66.7 ± 6.7 mL · kg−1 · min−1) performed the following protocols: an incremental test to determine lactate threshold and VO2max, 4 maximal constant-load tests to estimate critical power, and two 3-min bouts of cycle exercise, involving 2 min of constant-work-rate exercise at severe intensity followed by a 1-min all-out sprint test. This trial was performed without prior intervention and 10 min after prior heavy-intensity exercise (ie, 6 min at 90% critical power).

Results:

The mean response time of VO2 was shortened after prior exercise for both UT (30.7 ± 9.2 vs 24.1 ± 7.2 s) and T (31.8 ± 5.2 vs 25.4 ± 4.3 s), but no group-by-condition interaction was detected. The end-sprint performance (ie, mean power output) was improved in both groups (UT ~4.7%, T ~2.0%; P < .05) by prior exercise.

Conclusion:

The effect of prior heavy-intensity exercise on overall VO2 kinetics and short-term high-intensity exercise performance is independent of aerobic-training status.

Restricted access

Natália M. Bassan, Tadeu E.A.S. César, Benedito S. Denadai and Camila C. Greco

Purpose:

To analyze the relationship between the responses of isometric peak torque (IPT) and maximal rate of force development (RFDmax) with the changes in stroking parameters in an exhaustive exercise performed in front crawl.

Methods:

Fifteen male swimmers performed, on different days, the following protocols: maximal 400-m trial, strength tests before and after an exhaustive test at 100% of the mean speed obtained during the 400-m test, and the same procedures on day 2.

Results:

The IPT of elbow flexors (79.9 ± 19.4 and 66.7 ± 20.0 N·m) and elbow extensors (95.1 ± 28.0 N·m and 85.8 ± 30.5 N·m) was decreased after the swim test, as was RFDmax (521.8 ± 198.6 and 426.0 ± 229.9 N·m/s; 420.6 ± 168.2 and 384.0 ± 143.5 N·m/s, respectively). Stroke length decreased during the swim test (1.96 ± 0.22 and 1.68 ± 0.29 m/stroke), while stroke rate increased (37.2 ± 3.14 and 41.3 ± 4.32 strokes/min). The propulsive phases increased while the nonpropulsive phases decreased during the test. Significant correlation was found between the changes in IPT and stroke length, stroke rate and recovery (elbow flexors), and entry and catch phase (elbow extensors). In addition, significant correlation was found between the changes in RFDmax of elbow flexors with the changes in pull and recovery phases.

Conclusion:

Changes in swim technique during an exhaustive test can be, at least in part, associated with fatigue of the arm muscles.

Restricted access

Mariana F.M. Oliveira, Fabrizio Caputo, Ricardo D. Lucas, Benedito S. Denadai and Camila C. Greco

Purpose:

To identify the speed corresponding to anaerobic threshold using the D-max method for both blood lactate and biomechanical stroke parameters determined in an incremental swimming test and to compare this information with the speed corresponding to the maximal lactate steady state (SMLSS).

Methods:

Five male long-distance swimmers and 8 triathletes (N = 13; age 23.8 ± 9.5 y, height 1.76 ± 0.1 m, weight 71.3 ± 9.8 kg) performed the following protocols: maximal 400-m test to determine maximal aerobic speed (S400); 7 × 200-m incremental test to determine the speed corresponding to the D-max point on the blood lactate (SLa), stroke-rate (SSR), stroke-length (SSL), and stroke-index (SSI) responses; and two to four 30-min submaximal tests to determine the SMLSS.

Results:

SLA (1.18 ± 0.08 m/s), SSI (1.18 ± 0.08 m/s), SSR (1.17 ± 0.1 m/s), and SSL (1.16 ± 0.09 m/s) were not significantly different from each other or from SMLSS (1.13 ± 0.08 m/s). There were high correlations between SLA, SSI, SSR, SSL, and SMLSS (r = .91, .89, .85, and .80, respectively). The typical errors of estimate for SLA (3.2%), SSI (3.7%), SSR (4.1%), and SSL (4.7%) suggest good validity of these variables to predict SMLSS. Furthermore, all physiological and biomechanical variables were moderately to highly correlated with S400 (r = .73–.95).

Conclusions:

It is possible to obtain a physiological index of aerobic capacity and performance using simple biomechanical measurements during an incremental test without performing blood lactate analyses.

Restricted access

Fabiana A. Machado, >Luiz G. A. Guglielmo, Camila C. Greco and Benedito S. Denadai

The objective of this study was to verify the effect of the exercise mode on slow component of VO2 (VO2SC) in children aged 11–12 years during severe-intensity exercise. After determination of the lactate threshold (LT) and peak VO2 (VO2peak) in both cycling (CE) and running exercise (TR), fourteen active boys completed a series of “square-wave” transitions of 6-min duration at 75%∆ [75%∆ = LT + 0.75 × (VO2peak—LT)] to determine the VO2 kinetics. The VO2SC was significantly higher in CE (180.5 ± 155.8 ml • min−1) than in TR (113.0 ± 84.2 ml · min−1). We can conclude that, although a VO2SC does indeed develop during TR in children, its magnitude is considerably lower than in CE during severe-intensity exercise.