Time of day has no influence on performance and pacing during a 4km cycling time trial

2017 ◽  
Vol 20 ◽  
pp. e86-e87
Author(s):  
E. Zadow ◽  
C. Kitic ◽  
S. Wu ◽  
C. Abbiss ◽  
J. Peiffer ◽  
...  
2015 ◽  
Author(s):  
Ben J Lee ◽  
Charles D Thake

Background. The purpose of this study was to assess the reproducibility of cardiorespiratory and cellular (monocyte heat shock protein 70; mHSP70) responses to a fixed load hypoxic stress test (HST) and the reliability of a pre-loaded 16.1km cycling time trial (pTT) conducted under both normoxic and hypoxic conditions. Methods. Eighteen participants (age, 22 ± 4 years; height, 1.77 ± 0.04 meters; body mass, 76.8 kg; estimated body fat and VO2peak = 3.50 ± 0.60 L.min-1) were divided into three groups. Reliability of responses (HR, SPO2, VO2, VCO2, VE and RER) to the HST (FIO2 0.14; 15 minutes rest, 60 minutes cycling at 50% normoxic VO2peak) was assessed across 3 repeat trials (HST 1, 2 and 3, n = 6); mHSP70 was measured via flow cytometry before and after each HST (n = 5); resting HSP was also quantified on 4 separate occasions (n=5). Reliability of the pTT (15 min rest, 40 minutes cycling at 50% normoxic VO2peak) was assessed across 3 repeat normoxic (N; FIO2 ≈ 0.21; n=6) and 3 repeat hypoxic (FIO2 ≈ 0.14; n = 6) trials. All exercise trials were undertaken at the same time of day, following exercise and dietary controls, 7 days apart. Results. Intra-class correlation coefficients (ICC’s) for mean and peak HR, SpO2, VE , VO2 , VCO2 and BLa within each trial were improved from HST1 to HST2 (mean data: 0.99, 0.95, 0.75, 0.62, 0.70, 0.90; peak data: 0.98, 0.96, 0.64, 0.69, 0.74, 0.75) to HST2 and HST3 (ICC = 0.99, 0.97, 0.82, 0.85, 0.87 and 0.96 respectively). mHSP70 was a reproducible at rest without (ICC > 0.95) and with HSTs conducted in the previous 7 days (ICC > 0.95), with no difference in pre to post increases in mHSP70 observed between tests. The reliability for time to pTT completion was improved following one trial, and the CV (test 2 vs. 3) was similar under normoxic (CV = 0.62) and hypoxic conditions (CV = 0.63). Conclusion. Cardiorespiratory and cellular responses to the HST were reproducible and the pTT performance time reliable in both N and H. Since the reproducibility of the measurements in HST trials and reliability of pTT improved between the second and third trials one familiarization visit is recommended prior to employing these protocols in future studies.


PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e109954 ◽  
Author(s):  
Alan Lins Fernandes ◽  
João Paulo Lopes-Silva ◽  
Rômulo Bertuzzi ◽  
Dulce Elena Casarini ◽  
Danielle Yuri Arita ◽  
...  

2014 ◽  
Vol 28 (9) ◽  
pp. 2513-2520 ◽  
Author(s):  
Renato A.S. Silva ◽  
Fernando L. Silva-Júnior ◽  
Fabiano A. Pinheiro ◽  
Patrícia F.M. Souza ◽  
Daniel A. Boullosa ◽  
...  

2012 ◽  
Vol 15 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Mark G.L. Sayers ◽  
Amanda L. Tweddle ◽  
Joshua Every ◽  
Aaron Wiegand

2008 ◽  
Vol 26 (14) ◽  
pp. 1477-1487 ◽  
Author(s):  
Marc J. Quod ◽  
David T. Martin ◽  
Paul B. Laursen ◽  
Andrew S. Gardner ◽  
Shona L. Halson ◽  
...  

2005 ◽  
Vol 94 (3) ◽  
pp. 268-276 ◽  
Author(s):  
Tanja Oosthuyse ◽  
Andrew N. Bosch ◽  
Susan Jackson

2010 ◽  
Vol 5 (2) ◽  
pp. 140-151 ◽  
Author(s):  
Mohammed Ihsan ◽  
Grant Landers ◽  
Matthew Brearley ◽  
Peter Peeling

Purpose:The effect of crushed ice ingestion as a precooling method on 40-km cycling time trial (CTT) performance was investigated.Methods:Seven trained male subjects underwent a familiarization trial and two experimental CTT which were preceded by 30 min of either crushed ice ingestion (ICE) or tap water (CON) consumption amounting to 6.8 g⋅kg-1 body mass. The CTT required athletes to complete 1200 kJ of work on a wind-braked cycle ergometer. During the CTT, gastrointestinal (Tgi) and skin (Tsk) temperatures, cycling time, power output, heart rate (HR), blood lactate (BLa), ratings of perceived exertion (RPE) and thermal sensation (RPTS) were measured at set intervals of work.Results:Precooling lowered the Tgi after ICE significantly more than CON (36.74 ± 0.67°C vs 37.27 ± 0.24°C, P < .05). This difference remained evident until 200 kJ of work was completed on the bike (37.43 ± 0.42°C vs 37.64 ± 0.21°C). No significant differences existed between conditions at any time point for Tsk, RPE or HR (P > .05). The CTT completion time was 6.5% faster in ICE when compared with CON (ICE: 5011 ± 810 s, CON: 5359 ± 820 s, P < .05).Conclusions:Crushed ice ingestion was effective in lowering Tgi and improving subsequent 40-km cycling time trial performance. The mechanisms for this enhanced exercise performance remain to be clarified.


2009 ◽  
Vol 41 (1) ◽  
pp. 230-236 ◽  
Author(s):  
FLORENTINA J. HETTINGA ◽  
JOS J. DE KONING ◽  
CARL FOSTER

PLoS ONE ◽  
2013 ◽  
Vol 8 (9) ◽  
pp. e75399 ◽  
Author(s):  
Ralmony de Alcantara Santos ◽  
Maria Augusta Peduti Dal Molin Kiss ◽  
Marcos David Silva-Cavalcante ◽  
Carlos Rafaell Correia-Oliveira ◽  
Romulo Bertuzzi ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document