Running Power at Lactate Threshold and Lactate Turnpoint Are Unaltered by Treadmill Incline.

Area of Science:

• Exercise Physiology
• Sports Science
• Biomechanical Engineering

Background:

• Wearable technology provides novel metrics for monitoring exercise intensity.
• Running power output (rPO) is a promising metric, but its validity across different inclines needs investigation.
• Lactate threshold (LT) and lactate turnpoint (LTP) are key indicators of endurance performance.

Purpose of the Study:

• To investigate the effect of treadmill incline on wearable-derived running power output (rPO).
• To determine if rPO at the lactate threshold (LT) and lactate turnpoint (LTP) differs across inclines.
• To assess the consistency of rPO as an intensity metric during incline running.

Main Methods:

• Thirteen trained runners underwent rPO-matched treadmill tests at 0%, 5%, and 10% inclines.
• Running speed was adjusted to maintain consistent rPO across inclines.
• Oxygen uptake (V˙O2) and rPO were continuously measured; blood lactate was assessed periodically.
• LT and LTP were identified using established fitting models based on blood lactate and rPO data.

Main Results:

• The relationship between V˙O2 and rPO was consistent across all inclines.
• No significant differences were found in rPO at LT (0% vs. 5% vs. 10%) or LTP across the tested inclines.
• Oxygen uptake at LT and LTP also remained consistent regardless of treadmill incline.

Conclusions:

• Wearable-derived rPO at LT and LTP is consistent in highly trained runners across treadmill inclines from 0% to 10%.
• These findings validate the use of rPO for monitoring exercise intensity during incline running.
• rPO can be reliably used in training and performance settings irrespective of gradient changes.