The lactate and ventilatory thresholds in resistance training

Area of Science:

• Exercise Physiology
• Sports Science
• Biomechanical Analysis

Background:

• Lactate threshold (LT) and ventilatory threshold 1 (VT1) are key physiological markers in endurance exercise.
• Identifying these thresholds in resistance exercise, like the half-squat, can optimize training.
• Understanding the relationship between LT and VT1 in resistance exercise is crucial for training prescription.

Purpose of the Study:

• To identify the lactate threshold (LT) and first ventilatory threshold (VT1) during a graded resistance half-squat test.
• To determine if LT and VT1 occur at the same workload in this exercise modality.
• To compare visual inspection and algorithm methods for detecting LT and VT1.

Main Methods:

• Twenty-four young men underwent two test sessions.
• One-repetition maximum (1RM) was determined.
• An incremental load half-squat test was performed to locate LT and VT1, with VT1 calculated using ventilation, ventilatory equivalent of oxygen, or end-tidal oxygen pressure.

Main Results:

• LT and VT1 were found at similar exercise intensities during the incremental half-squat test.
• Algorithm-based detection showed LT at 24.8% 1RM and VT1 at 23.7% 1RM (non-significant difference).
• Both visual inspection and algorithm methods yielded comparable LT and VT1 values, with strong positive correlations (r > 0.761, ICC > 0.864).

Conclusions:

• The lactate threshold (LT) and first ventilatory threshold (VT1) are readily identifiable during an incremental resistance half-squat test.
• Both thresholds manifest at similar workloads, supporting their combined use.
• LT and VT1 can effectively define physiological stages and prescribe exercise intensity for resistance training.