Overview

Oxygen Interval Surges are short, intense efforts separated by equally short recoveries. They’re designed to lift your VO₂max—the maximum amount of oxygen your body can use—and make you more efficient at riding hard. A session typically includes 2–4 blocks of repeated bursts lasting 15–45 seconds at 120–130% of FTP, with very easy spinning in between. Each block lasts around 9–15 minutes, with 3–5 minutes of recovery between them.

Key Benefits

• Pushes oxygen use and heart rate close to maximum
• Improves VO₂max and overall aerobic power
• Raises FTP and supra-threshold durability
• Helps you recover faster after hard surges
• Efficient way to accumulate high-intensity training time

How to Apply This

1. Warm up for 15–20 minutes with some short efforts
2. Complete 2–4 blocks of 9–15 minutes each
3. During each block, alternate between 15–45 seconds ‘hard’ (120–130% FTP) and 15–30 seconds ‘easy’ spinning
4. Example: 3x9 min – 30 sec ‘hard’ at ~125% FTP followed by 15 sec ‘easy’
5. Take 3–5 minutes of easy pedaling between blocks
6. Overall feel should be 8/10 on RPE—demanding, with heavy breathing

Pro Tip

Perform this session indoors or on a steady climb with a mild gradient so you can manage both the surges and the recoveries. Keep the ‘easy’ portions truly easy—just enough to spin the pedals—so you can hit the hard efforts consistently across the whole block.