What Is the Best Vo2 Max Workout?

Training at or near VO₂max, the exercise intensity at which an athlete reaches his or her maximal rate of oxygen consumption, has long been known as an effective way to increase aerobic capacity (which is what VO₂max measures). That’s important because aerobic capacity, or the ability to use oxygen to power muscle contractions, is a major contributor to endurance performance.

In recent years, scientists have become interested in designing interval workouts that maximize the amount of time an athlete spends at or near VO₂max, without simply making the workouts harder and harder. The idea is that such workouts will yield a bigger boost in aerobic capacity.

As an athlete, you might be interested in knowing which of these workouts is most effective for increasing VO₂max. Let’s take a look at a few candidates.

1. Long Intervals With Surges

• Best for: Maximizing time spent near VO2 max
• Why it works: Adding short surges within longer intervals may help athletes spend more total time at very high oxygen demand without making the workout feel harder
• Example: 6 × 5 minutes with 3 × 30-second surges built into each interval

Traditional interval workouts focus on a single, uniform intensity. But in 2019, scientists at the University of Kent and Inland Norway University created and tested a workout that featured work intervals of variable intensity, believing it might enable athletes to spend more time at or very near VO₂max.

The workout consisted of six, 5-minute intervals ridden at 85% of maximum aerobic power (or MAP, which is the highest power output an individual cyclist achieves in a ride to failure at increasing power levels) separated by 2.5-minute active recoveries. The added wrinkle was the insertion of three, 30-second surges at 100% of MAP within each interval, with the baseline effort lowered slightly to 77% of MAP to make the intervals feasible as a whole.

The new workout was tested on 14 trained cyclists, who completed both it and a more traditional constant-intensity interval workout on separate occasions. On average, the cyclists spent 6:50 of cumulative time above 90% of VO₂max during the variable-intensity workout compared to just 4:46 above 90% of VO₂max during the traditional workout. After each session, the cyclists were asked to rate how difficult it was, and despite the discrepancy in physical demands, the two versions were judged about equal — 6.0 vs. 6.6 on a 1-10 scale of perceived effort. These findings, which were reported in the International Journal of Sports Physiology and Performance, indicate that the variable-intensity interval workout is more physiologically stimulating without being harder.

2. Short Intervals With Very Short Recovery

• Best for: Accumulating a large amount of time near VO2 max without relying on long continuous efforts
• Why it works: Short work bouts let athletes repeat hard efforts more times, while very short recoveries help keep oxygen consumption elevated
• Example: 3 sets of 13 × 30 seconds hard / 15 seconds easy, with 3 minutes easy between sets

One year after this study appeared, some of the same researchers tested a different workout intended to serve essentially the same purpose. The 30-15 workout, as I call it, consists of large numbers of 30-second intervals punctuated by 15-second active recoveries. The reasoning behind this design was that the shorter-than-normal intervals would allow athletes to do lots of them, while the even shorter active recovery segments would ensure that the rate of oxygen consumption remained high. 

The 30-second efforts were done at 94% of MAP, which is sustainable for about 15 minutes in a time trial, and the 15-second active recoveries at 77% of MAP. The complete workout comprised three sets of 13 intervals with 3 minutes of easy pedaling between sets. This format was tested against a traditional VO₂max workout (4 x 5:00 @ 85% MAP/2:30 active recovery).

Eighteen cyclists were separated into two groups, one of which did the traditional workout three times per week for three weeks with supplemental low-intensity riding, while a second group did the 30-15 workout thrice weekly alongside the same amount of low-intensity riding as the first group.

All of the cyclists completed performance tests before and after the three-week intervention. On average, members of the 30-15 group experienced a 4.7 increase in power output in a 20-minute time trial, whereas performance actually decreased slightly in the other group. Rønnestad’s team attributed these disparate outcomes to differences in mean power output and cumulative time spent above 90% of VO₂max between the two workouts. Again, though, the subjects rated the two sessions about equal in perceived difficulty.

3. Decreasing Intervals

• Best for: Reaching VO2 max quickly, then extending time near it before fatigue forces the workout to end
• Why it works: Starting with longer intervals helps bring oxygen uptake up fast, while switching to shorter reps may help athletes keep going longer
• Example: 3:00 hard / 2:00 easy, then 2:00 / 1:20, then 1:00 / 0:40, then 0:45 / 0:30, then 0:30 / 0:20 to exhaustion

Not to be outdone, researchers at the University of Udine, Italy unveiled their own innovative VO₂max workout in 2020. This one featured high-intensity work bouts that steadily decreased in length throughout the session, a design based on past research showing that longer intervals at high intensity allow athletes to reach VO₂max quickly, whereas short intervals allow them to continue longer before reaching exhaustion. Would a set of decreasing intervals offer the best of both worlds, comparing favorably to a set of long intervals and a set of short intervals in these respects?

To find out, the researchers had 12 cyclists complete the following three workouts:

In all three workouts, the high-intensity efforts were performed at the highest power output each individual cyclist could sustain for five minutes and were repeated to exhaustion. Each subject completed all three workouts in random order on separate occasions. On average, the cyclists lasted 13:20 and spent 5:12 above 90% of VO₂max in the decreasing intervals workout, compared to 11:54/3:02 in the short intervals workout, and 11:04/2:59 in the long intervals workout.

In a paper published in the European Journal of Applied Physiology, the researchers concluded that “despite the higher stimulation of VO₂, the rate of perceived exertion and the other physiological parameters at the end of the exercise were not different compared with long- or short-interval HIIT, suggesting that (the decreasing intervals format) was not more demanding. In light of the favorable or similar physiological and/or perceptual responses to (decreasing intervals) compared to the other protocols and given the improved capability to prolong the time close to VO₂ peak, it could be used as a preferable method to elicit similar or greater physiological adaptations.”

Which Workout Is the Best At Increasing VO2 Max?

You probably knew all along that the question posed in the title of this article was a trick question, and indeed it is.

VO2 max training is about pushing your body to use as much oxygen as possible. The goal isn’t just to “go hard.” It’s about spending enough time at a high aerobic demand to trigger adaptation.

Different workouts get you there in different ways. Some bring you to that limit quickly. Others help you stay there longer. Both matter.

Why Research Can’t Identify a Single “Best” Workout

Science is great, but it has certain limitations. The conditions that scientists are required to create in order to make head-to-head comparisons between workouts are artificially simple compared to the real world.

The conditions required to compare workouts in a lab are far simpler than real-world training. If one workout increases VO2 max more than another over three weeks, there’s no guarantee the same would hold true over nine weeks, let alone across an entire season.

There’s also a bigger question: even if one workout produces a slightly higher VO2 max in a study, does that actually translate to better race performance?

That’s much harder to answer. And it’s exactly the kind of context most studies lack.

Why You Shouldn’t Rely on One VO2 Max Workout

The idea of a “best” workout assumes that once you find it, you should keep doing it. But that’s rarely the right approach.

Whether you’re trying to improve VO2 max, lactate threshold, or endurance, progress comes from using a range of workout formats, not repeating the same one over and over.

Aerobic capacity isn’t a single trait. It’s made up of multiple physiological systems, each responding differently to training. Even low-intensity training develops aspects of aerobic fitness that don’t fully overlap with high-intensity work. And within VO2 max training itself, different interval formats stress different underlying mechanisms.

That’s why no single workout can do it all—and why limiting yourself to one approach can leave gaps in your development.

FAQs

References

Almquist, N. et al. (2020, April 30). Systemic and muscular responses to effort-matched short intervals and long intervals in elite cyclists. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32267032/

Bossi, A. et al. (2019, October). Optimizing Interval Training Through Power-Output Variation Within the Work Intervals. Retrieved from https://www.researchgate.net/publication/336641479_Optimizing_Interval_Training_Through_Power-Output_Variation_Within_the_Work_Intervals

Rønnestad, B. et al. (2020, May 30). Superior performance improvements in elite cyclists following short-interval vs effort-matched long-interval training. Retrieved from https://pubmed.ncbi.nlm.nih.gov/31977120/

Vaccari, F. et al. (2020, August 11). High-intensity decreasing interval training (HIDIT) increases time above 90% 𝑉˙V˙O₂peak. Retrieved from https://link.springer.com/article/10.1007/s00421-020-04463-w