Aerobic high-intensity intervals improve VO2max more than moderate training

Area of Science:

• Exercise Physiology
• Cardiovascular Training

Background:

• Aerobic endurance training is crucial for enhancing cardiovascular function.
• Different training intensities and methods may yield varying physiological adaptations.

Purpose of the Study:

• To compare the effects of aerobic endurance training at different intensities and methods, matched for total work and frequency.
• To examine responses in maximal oxygen uptake (VO2max), stroke volume (SV), blood volume, lactate threshold (LT), and running economy (CR).

Main Methods:

• Forty moderately trained males were divided into four groups: long slow distance (70% HRmax), lactate threshold (85% HRmax), 15/15 interval running (90-95% HRmax), and 4x4 min interval running (90-95% HRmax).
• All protocols involved 3 sessions per week for 8 weeks with matched total oxygen consumption.

Main Results:

• High-intensity interval training (15/15 and 4x4 min) significantly increased VO2max compared to long slow distance and lactate threshold training.
• VO2max increased by 5.5% (15/15) and 7.2% (4x4 min).
• Stroke volume (SV) increased by approximately 10% following interval training.

Conclusions:

• High-aerobic intensity interval training is more effective for improving VO2max than training at lactate threshold or 70% HRmax.
• Observed increases in VO2max correlate with changes in SV, suggesting a strong physiological link.