How often should you do VO2max workouts? Weeks to results

VO2max sessions are the most potent and the most tiring workouts in an endurance plan. Too few and fitness stalls; too many and the quality drops while fatigue builds. This guide covers VO2max training frequency, recovery between sessions, weekly placement, how long it takes to see results, and what to do when progress stalls. For the sessions themselves, see VO2max intervals compared.

How often should you do VO2max workouts?

Situation	VO2max sessions per week	Duration	Notes
Beginner, first 4–6 weeks	0–1	Ongoing	Easy aerobic work alone raises VO2max at first
General fitness or health	1	Ongoing	Keeps gains and slowly builds them
Focused block	2	4–8 weeks	Matches most successful trials
Short overload block	3 or more	1–3 weeks	Experienced athletes only, then recover
Maintenance after a block	1 every 7–10 days	Ongoing	Intensity keeps fitness with less volume

Most of the evidence used two or three interval sessions a week. Helgerud et al. (2007) used three sessions a week for eight weeks; Rønnestad et al. (2015) used two a week for ten weeks in cyclists. The Bacon et al. (2013) meta-analysis only included studies with three or more training days a week over 6 to 13 weeks, and found an average VO2max gain of 0.51 L/min. In Generation 100, adults aged 70 to 77 did two interval sessions weekly for five years.

Note that "three days a week" in those studies often meant all training, not three intervals on top of a normal running week. For people who also run easy most other days, two VO2max sessions a week is plenty. If you are unsure, start with one and add a second only when you recover well.

VO2max training frequency and total dose

Frequency matters because it drives total dose. In Montero and Lundby (2017), 78 healthy adults trained one to five 60-minute sessions a week for six weeks. The share of non-responders in fitness fell from 69% with one session to 40%, 29%, 0% and 0% with two to five. When non-responders added two more sessions a week for another six weeks, all of them improved. The lesson: if one session a week does nothing for you, more total training usually does. More on this in training volume for VO2max and VO2max trainability.

Short, dense blocks also work. In Breil et al. (2010), junior alpine skiers did 15 sessions of 4×4 in 11 days and raised VO2max by 6.0%, measured a week later. That is an advanced, short-term strategy, not a weekly routine.

Recovery between VO2max sessions

• Leave 48 to 72 hours between hard sessions. Tuesday and Friday, or Tuesday and Saturday, work well.
• Easy means easy in between: conversational pace or zone 1 to 2 (easy run pace).
• Don't stack a long run or threshold session the day after a VO2max workout during a block.
• Watch the signs: a resting heart rate several beats above normal, a falling HRV trend or heavy legs on the warm-up suggest you need another easy day (resting heart rate, HRV and recovery).
• Sleep and fuel: hard intervals run on carbohydrate. Eat enough on the day before and after.

Buchheit and Laursen point out that intervals at or above VO2max pace put a high load on muscles and tendons, and runners can cover 6 to 8 km at that speed in a single session. That neuromuscular cost, more than the heart, is often what limits how often you can repeat them. Bikes, rowers and uphill reps reduce it.

Weekly placement of VO2max workouts

Plan	Mon	Tue	Wed	Thu	Fri	Sat	Sun
1 session	Easy	VO2max	Easy	Rest	Easy	Long easy	Rest or easy
2 sessions	Easy	VO2max	Easy	Rest	VO2max	Long easy	Easy
2 sessions + threshold	Easy	VO2max	Easy	Threshold	Rest	VO2max short	Long easy

The third pattern suits experienced runners only. If you race at weekends, move the VO2max day to midweek and treat the race as the second hard session. Keep around 80% of your training easy, as in 80/20 training, and see periodisation for endurance for how VO2max blocks fit a season.

How long does it take to increase VO2max?

• Weeks 1 to 3: blood volume rises quickly and VO2max can begin to move. In Hickson et al. (1977), untrained people on a very strenuous programme (intervals and hard runs, six days a week) gained 5% in the first week.
• Weeks 4 to 8: the typical window for clear gains. Wen et al. (2019) found that even programmes of 4 weeks or less improved VO2max, but programmes of 4 to 12 weeks gave larger effects. Helgerud's 4×4 group gained 7.2% in eight weeks.
• Weeks 8 to 12: gains continue if load progresses. Hickson's subjects improved in a straight line for 10 weeks, a 44% total rise, though they started untrained and trained very hard.

Beginners improve the most. Milanović et al. (2015) found larger gains in people with lower starting fitness and in longer interventions. A trained runner may gain only a few percent in a block. Your watch may also lag behind real change (how accurate is watch VO2max).

Why VO2max plateaus

After roughly three months of the same training, gains slow. Reasons include approaching your genetic ceiling, adapting to a stimulus that no longer challenges you, and accumulated fatigue. To restart progress:

1. Change the format: switch from 4×4 to 30/15 or 5×5.
2. Add easy volume: more aerobic base supports more intensity.
3. Run a structured block, then a lighter maintenance phase: see the 8-week VO2max training block.
4. Take a recovery week if you feel flat: see overtraining syndrome signs.

Stopping costs less than you might fear in the short term, but fitness does fade: see how fast you lose VO2max. One hard session every 7 to 10 days usually holds most of it.

Checking progress

Retest every 6 to 8 weeks under similar conditions: a 5k or 3k race, a Cooper test, or the same interval session at the same heart rate. Enter the result in the VO2max calculator or estimate it from race times with the VO2max running calculator. Keep heart rate targets current with the heart rate zone calculator, and explore more on VO2max for running. If you are choosing what to do in those sessions, start with the best training for VO2max.

Safety: if you have heart disease, high blood pressure, or symptoms such as chest pain, palpitations or dizziness, get medical clearance before doing hard intervals.

Sources

• Helgerud J, et al. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc, 2007.
• Rønnestad BR, et al. Short intervals induce superior training adaptations compared with long intervals in cyclists: an effort-matched approach. Scand J Med Sci Sports, 2015.
• Bacon AP, Carter RE, Ogle EA, Joyner MJ. VO2max trainability and high intensity interval training in humans: a meta-analysis. PLoS One, 2013.
• Montero D, Lundby C. Refuting the myth of non-response to exercise training: 'non-responders' do respond to higher dose of training. J Physiol, 2017.
• Breil FA, et al. Block training periodization in alpine skiing: effects of 11-day HIT on VO2max and performance. Eur J Appl Physiol, 2010.
• Hickson RC, Bomze HA, Holloszy JO. Linear increase in aerobic power induced by a strenuous program of endurance exercise. J Appl Physiol, 1977.
• Wen D, et al. Effects of different protocols of high intensity interval training for VO2max improvements in adults: a meta-analysis of randomised controlled trials. J Sci Med Sport, 2019.
• Milanović Z, Sporiš G, Weston M. Effectiveness of high-intensity interval training (HIT) and continuous endurance training for VO2max improvements: a systematic review and meta-analysis of controlled trials. Sports Med, 2015.
• Buchheit M, Laursen PB. High-intensity interval training, solutions to the programming puzzle. Part II: anaerobic energy, neuromuscular load and practical applications. Sports Med, 2013.
• Stensvold D, et al. Effect of exercise training for five years on all cause mortality in older adults: the Generation 100 study. BMJ, 2020.