Assessing the rate of torque development in sprint cycling: a methodological study

Area of Science:

• Sports Science
• Exercise Physiology
• Biomechanics

Background:

• Rate of torque development (RTD) is a critical factor in sprint cycling performance.
• Accurate measurement of RTD requires careful consideration of sprint protocols, including resistance and duration.
• Previous research has not definitively established the optimal conditions for reliable RTD assessment in cyclists.

Purpose of the Study:

• To investigate the magnitude and between-day reliability of RTD at the start of a cycling sprint.
• To determine how variations in sprint resistance, duration, and pedal downstroke affect RTD measurements.
• To identify the most reliable methods for assessing RTD in well-trained cyclists.

Main Methods:

• Nineteen well-trained cyclists completed familiarisation and three testing sessions.
• Participants performed 1-s and 5-s sprints at moderate, heavy, and very heavy resistances.
• RTD measures (average, peak, 0-100 ms, 0-200 ms) were calculated for specific pedal downstrokes and averages.

Main Results:

• RTD was greatest in pedal downstroke 3 across all resistance levels.
• The most reliable RTD measures (average, peak, and 0-200 ms) were obtained using the average of downstrokes 2 and 3 during 5-s sprints at heavy or very heavy resistances (ICC ≥ 0.8, CV ≤ 10%).
• RTD 0-100 ms and all measurements from downstroke 1 were found to be unreliable.

Conclusions:

• A 5-second cycling sprint with heavy or very heavy resistance provides the most reliable assessment of RTD in cyclists.
• The average of pedal downstrokes 2 and 3 is recommended for reliable RTD evaluation.
• 1-second sprints are insufficient for achieving reliable RTD measurements due to the limited number of pedal downstrokes.