ecss presentation
TRANSCRIPT
MENTAL FATIGUE DOES NOT IMPAIR
ALL-OUT SPRINT IN ELITE TRACK CYCLISTS
BUT IT ALTERS PERCEPTUAL RESPONSES
DURING CONTINUOUS SUBMAXIMAL
EXERCISE
Dr. Walter Staiano
TEAMDANMARK (Danish Institute of Elite Sport)
Mental Fatigue
Psychobiological state caused by prolonged demanding cognitive activity and characterized by subjective feelings of “tiredness” and “lack of energy”
Main Psychological Features
• Subjective feelings of tiredness and lack of energy
(mood), and aversion to further effort (motivation)
• Cognitive Performance:
• Impaired vigilance
• Impaired decision-making
• Impaired self-regulation
• (Boksem and Tops, 2008)
(Marcora et al., JAP 2009) and (Pajeaux et al. 2014)
Control
Mental Fatigue
0 2 4 6 8 10 12 14 16
Time to exhaustion (min)
P <0.05
Mental Fatigue and Endurance Performance
Aims of the study
• First aim was to assess if mental fatigue induced by a cognitive demanding task would affect all-out sprint in elite sprinter track cyclists.
• Second aim was to asses if the same cognitive demanding task would affect physiological, psychological and perceptual responses during a ramp test at constant load.
Methods• Subjects: 10 elite track cyclists (male)
• Design: Randomized, counterbalanced, cross-over, experimental
• Experimental treatment: Stroop task for 30 min
• Control treatment: neutral documentary
• Submaximal Ramp test: 3 x 5 min at 100, 150 and 200 W
• Sprint performance: 15 sec all out sprint at fix cadence 125
• Psychological measures: task-related motivation; 4DMS mood scale, VAS Scale, NASA TLX, RPE (Borg, 1998)
• Physiological measures: blood lactate, heart rate and RPM during ramp test and all out sprint.
BET / 11. oktober 2016
Results 1
NASA TLX
MF Control p
Nasa TLX MentalDemand 70±24 22±19 **
Nasa TLX PhysicalDemand 13.5±10 10.5±8
Nasa TLX Effort 69.5±20 26.0±21 **
Nasa TLX Frustration 66.5±20 26.0±17 **
VAS
All-out sprint test
MF Control MBI
Peak Power 1526±157 1519±164 89% is likely trivial
FI 40±9 41±9 Unclear
Mean Power 1211±171 1203±178 83% is likely trivial
Conclusion
• 30 min of Stroop task did not impair 15sec all-out sprint in elite track sprinter cyclists
• However the cognitive task was sufficient to induce mental fatigue and produce an negative effect on RPE during a submaximal exercise at constant load.
Practical Implication: Track Cycling
Physiological Component
• Power output Production
• Aerobic Capacity (Endurance)
• Anaerobic capacity (Sprinter)
Technical and strategic skills
• Pacing
• Strategy to adopt
• Decision making
• Reaction time
• Posture