TY  - JOUR
A1  - Scharhag-Rosenberger, Friederike
A1  - Carlsohn, Anja
A1  - Lundby, Carsten
A1  - Schueler, Stefan
A1  - Mayer, Frank
A1  - Scharhag, Jürgen
T1  - Can more than one incremental cycling test be performed within one day?
JF  - European journal of sport science : official journal of the European College of Sport Science
N2  - Changes in performance parameters over four consecutive maximal incremental cycling tests were investigated to determine how many tests can be performed within one single day without negatively affecting performance. Sixteen male and female subjects (eight trained (T): 25 +/- 3 yr, BMI 22.6 +/- 2.5 kg center dot m(-2), maximal power output (P-max) 4.6 +/- 0.5 W center dot kg(-1); eight untrained (UT): 27 +/- 3 yr, BMI 22.3 +/- 1.2 kg center dot m(-2), P-max 2.9 +/- 0.3 W center dot kg(-1)) performed four successive maximal incremental cycling tests separated by 1.5 h of passive rest. Individual energy requirements were covered by standardised meals between trials. Maximal oxygen uptake (VO2max) remained unchanged over the four tests in both groups (P = 0.20 and P = 0.33, respectively). P-max did not change in the T group (P = 0.32), but decreased from the third test in the UT group (P < 0.01). Heart rate responses to submaximal exercise were elevated from the third test in the T group and from the second test in the UT group (P < 0.05). The increase in blood lactate shifted rightward over the four tests in both groups (P < 0.001 and P < 0.01, respectively). Exercise-induced net increases in epinephrine and norepinephrine were not different between the tests in either group (P 0.15). If VO2max is the main parameter of interest, trained and untrained individuals can perform at least four maximal incremental cycling tests per day. However, because other parameters changed after the first and second test, respectively, no more than one test per day should be performed if parameters other than VO2max are the prime focus.
KW  - Maximal oxygen uptake
KW  - cardiopulmonary exercise testing
KW  - consecutive tests
KW  - study design
KW  - exhaustion
KW  - fatigue
Y1  - 2014
U6  - https://doi.org/10.1080/17461391.2013.853208
SN  - 1746-1391
SN  - 1536-7290
VL  - 14
IS  - 5
SP  - 459
EP  - 467
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Prieske, Olaf
A1  - Demps, Marie
A1  - Lesinski, Melanie
A1  - Granacher, Urs
T1  - Combined Effects of Fatigue and Surface Instability on Jump Biomechanics in Elite Athletes
JF  - International journal of sports medicine
N2  - The present study aimed to examine the effects of fatigue and surface instability on kinetic and kinematic jump performance measures. Ten female and 10 male elite volleyball players (18 +/- 2 years) performed repetitive vertical double-leg box jumps until failure. Pre and post fatigue, jump height/performance index, ground reaction force and knee flexion/valgus angles were assessed during drop and countermovement jumps on stable and unstable surfaces. Fatigue, surface condition, and sex resulted in significantly lower drop jump performance and ground reaction force (p0.031, 1.1d3.5). Additionally, drop jump knee flexion angles were significantly lower following fatigue (p=0.006, d=1.5). A significant fatiguexsurfacexsex interaction (p=0.020, d=1.2) revealed fatigue-related decrements in drop jump peak knee flexion angles under unstable conditions and in men only. Knee valgus angles were higher on unstable compared to stable surfaces during drop jumps and in females compared to males during drop and countermovement jumps (p0.054, 1.0d1.1). Significant surfacexsex interactions during countermovement jumps (p=0.002, d=1.9) indicated that knee valgus angles at onset of ground contact were significantly lower on unstable compared to stable surfaces in males but higher in females. Our findings revealed that fatigue and surface instability resulted in sex-specific knee motion strategies during jumping in elite volleyball players.
KW  - stretch-shortening cycle
KW  - knee joint angle
KW  - exhaustion
KW  - injury risk
KW  - gender
Y1  - 2017
U6  - https://doi.org/10.1055/s-0043-111894
SN  - 0172-4622
SN  - 1439-3964
VL  - 38
SP  - 781
EP  - 790
PB  - Thieme
CY  - Stuttgart
ER  -