Oxygen uptake in maximal effort constant rate and interval running.

Area of Science:

• Exercise Physiology
• Sports Science
• Human Performance

Background:

• Understanding oxygen consumption during different running intensities is crucial for training optimization.
• Maximal effort interval running (INT) and constant-rate running at lactate threshold (CRLT) are common training protocols.
• Previous research has not directly compared the oxygen cost of these two protocols when matched for duration.

Purpose of the Study:

• To compare the average oxygen uptake (VO2) and distance covered during maximal effort interval running versus constant-rate running at lactate threshold, matched for time.
• To determine if different maximal effort running protocols elicit significantly different oxygen demands.
• To compare these maximal effort protocols against a submaximal constant-rate run.

Main Methods:

• Ten recreational male runners with a mean VO2max of 4158 mL·min⁻¹ participated.
• Participants completed three 20-minute running conditions: CRLT, INT (2 min VO2max speed/2 min 50% VO2max speed, repeated 5 times), and a constant-rate submaximal run (CR sub-max).
• Average VO2 and distance covered were measured and compared using mean and 95% confidence intervals.

Main Results:

• Average VO2 was not significantly different between INT (3451 mL·min⁻¹, 83% VO2max) and CRLT (3464 mL·min⁻¹, 84% VO2max).
• Both INT and CRLT showed significantly higher average VO2 compared to CR sub-max (3464 mL·min⁻¹, 76% VO2max).
• Distance covered was significantly greater during CRLT (4431 m) compared to INT and CR sub-max (4070 m).

Conclusions:

• A 20-minute maximal effort constant-rate run at lactate threshold requires a similar oxygen uptake to a 20-minute maximal effort interval run.
• Despite similar oxygen demands, constant-rate running at lactate threshold results in a greater distance covered.
• These findings suggest that both protocols are effective for achieving high oxygen consumption during training, but CRLT may offer superior distance-based training benefits within the same time frame.