Journal of Sports Science and Medicine
Journal of Sports Science and Medicine
ISSN: 1303 - 2968   
Ios-APP Journal of Sports Science and Medicine
Androit-APP Journal of Sports Science and Medicine
Views
6671
Download
174
from September 2014
 
©Journal of Sports Science and Medicine (2002) 01, 136 - 140

Research article
Effect of Time of Day on the Relationship Between Lactate and Ventilatory Thresholds: A Brief Report
Ufuk Şekir1, , Fadil Özyener2, Hakan Gür1
Author Information
1 Medical Faculty of Uludag University, Department of Sports Medicine, Bursa, Turkey
2 Medical Faculty of Uludag University, Department of Physiology, Bursa, Turkey

Ufuk Şekir
✉ Medical Faculty of Uludag University, Department of Sports Medicine, 16059-Bursa, Turkey
Email: ufuksek@hotmail.com
Publish Date
Received: 14-05-2002
Accepted: 22-09-2002
Published (online): 01-12-2002
Share this article
 
 
ABSTRACT

The purpose of this investigation was to study the effect of time of day on the relationship between lactate (LT) and ventilatory thresholds (VT) of pulmonary oxygen uptake (VO2). Seven moderately active male volunteers (26.3 ± 3.0 years, 1.74 ± 0.08 m, 76 ± 5 kg) performed a maximal incremental test (increases of 30 W every 2 min) on a cycle ergometer on consecutive days at 0900 h, 1400h and 1900 h in a randomized fashion. The anaerobic threshold was determined using both ventilatory gas analysis and blood lactate measures. Each of the following variables was recorded both at VT and the LT; heart rate (HR, beats.min-1), minute ventilation (VE, L.min-1), respiratory exchange ratio (RER), time to threshold (Time, sec), oxygen uptake (VO2, ml·kg-1.min-1) and VO2 as a percentage of maximal oxygen uptake (%VO2max). The correlations between VT and LT variables analyzed by Pearson product moment correlations for each time of day. ANOVA was used to compare the data obtained at different times of the day. There were no significant differences for the data related to time of day either for ventilatory gas analysis or lactate measurements. The correlation coefficients between VT and LT variables were moderate to high (r=0.56-0.94) for time of day. However, the correlations for HR, VO2, and %VO2max (r=0.81-0.94) were slightly stronger compared with Time, VE and RER (r=0.56-0.88). It was concluded that, the data at VT and LT were not influenced by time of day.

Key words: Anaerobic threshold, circadian rhythm


           Key Points
 
 
Home Issues About Authors
Contact Current Editorial board Authors instructions
Email alerts In Press Mission For Reviewers
Archive Scope
Supplements Statistics
Most Read Articles
  Most Cited Articles
 
  
 
JSSM | Copyright 2001-2020 | All rights reserved. | LEGAL NOTICES | Publisher

It is forbidden the total or partial reproduction of this web site and the published materials, the treatment of its database, any kind of transition and for any means, either electronic, mechanic or other methods, without the previous written permission of the JSSM.

This work is licensed under a Creative Commons License Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.