VO2max intervals: 5 x 3 minutes hard

Five 3-minute efforts at roughly 3K to 5K race pace, the session that raises your aerobic ceiling.

How to run it

Warm up 10 minutes easy, run five reps of 3 minutes hard with 2 minutes of jogging between them, then finish with 10 minutes easy.

“Hard” means RPE 8 to 9: the pace you could hold for a 5K race, maybe a few seconds per kilometer quicker. Breathing is deep and rhythmic and you can manage a word or two, nothing more. Daniels calls this I-pace, and the goal is to spend time close to maximal oxygen uptake, not to sprint. The first rep should feel almost too controlled. If rep one is your fastest, you started too fast.

The recovery is a jog, not a walk. Keep moving at whatever pace lets you start the next rep on time. The 2-minute jog is short on purpose so that oxygen uptake stays high going into the next effort.

For a pace target, take your current 5K time and run the reps at that pace or slightly faster. If you have no recent 5K, the race predictor will estimate one from any recent hard run. By heart rate you will drift up to 90 to 95 percent of max by the end of each rep, but do not chase heart rate in the first minute; it lags behind the effort.

No track needed. Run these on a flat road, path or gently rolling loop and let the watch time each rep. On windy or hilly routes, go by effort rather than pace.

How to scale it

Easier: 10 min easy, 4 x 3 min hard with 2 min jog, 10 min cool down or shorten the reps with 10 min easy, 6 x 2 min hard with 2 min jog, 10 min cool down.

Harder: 10 min easy, 6 x 3 min hard with 2 min jog, 10 min cool down or 10 min easy, 5 x 4 min hard with 2 min jog, 10 min cool down.

Keep total hard time between 12 and 24 minutes. Beyond that the pace falls apart and the session stops being VO2max work.

Common mistakes

• Running the first rep like a 1500 m race. Aim for even splits with a slightly faster last rep.
• Walking or standing during recoveries. Keep it a jog; starting the next rep still breathing hard is the point.
• Doing this twice a week on top of racing. Once a week is plenty, with an easy day on either side.

Let the coach schedule it

When TextFit’s coach puts a session like this in your plan, it counts as a hard day: never next to another one, and no more than two a week (three above eight sessions). It reaches your Garmin or Apple Watch as a structured workout with each rep and each jog as its own step and pace targets worked out from your current fitness, and the watch beeps at every change so you can run by feel and let it handle the clock. If the day stops working, tell the coach in the chat and it moves or eases the session; every change shows with Undo. Try TextFit free for 14 days on iPhone.