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)

Effect of Mental Fatigue on psychological factors

Motivation

Mood

Perceived Ability

(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

Mental Fatigue and anaerobic performance

Force during 5 s Maximal

Voluntary Contraction (MVC)

“Sport is a demanding activity requiring more cognitive skills that is often appreciated.”

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

Ramp test: Physiological parameters

Ramp Test: RPE

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

External Sources of Mental Fatigue

BET / 11. oktober 2016

Thanks to:

Prof. Samuele Marcora

Dr Paolo Menaspa

Dr David Martin

Nicholas Flyger

Thanks to University of Kent and AIS