Tag Archives: vo2max

VO2 Intervals

VO2 intervals are one of the best ways to improve distance running. If you want to get faster then max out your oxygen use.

VO2 intervals are the most important fast session in my running plan. This is a run not to skip.

As with all running there a multiple ways to reach the same goal. This is the approach I am taking and what tends to work well for many.


The intensity you want to work at is close to your maximal oxygen uptake (VO2max). Aiming for 95-100% of VO2max. But it is ridiculously hard and expensive to measure your VO2 while out running. We need another way.

Heart rate can help. Typically hitting between 90-100% of maximal heart rate (HRmax) gets you in the right area. But not always. Heart rate can plateau while your intensity rises and you may be working harder than required. Also your HR may not rise to the desired range at the start of the session.

Using pace can be a little more accurate. You will be aiming for between 5000m to 3000m race pace. The slower you race times the more you would lean towards 3000m pace. Another way to think is we can only hold our VO2max speed for between 9-14 minutes. That is the pace and intensity of the intervals.


The interval length should be between 2-6 minutes. Most studies have shown between 3-5 minutes giving the greatest results.


Recovery is designed so you can perform your next interval. We want to avoid early fatigue.

Many sources will give a ratio for recovery such as 2:1 or 1:1, which appears to work in the research. My preferred approach is to take between 3-5 minutes between intervals. Shorter than 3 minutes tends to drop the standard in the last couple of intervals. Beyond 5 minutes seems to reduce the overall effectiveness of the session.

Keep the intensity at a comfortable run. Below anaerobic threshold. At your usual easy run pace. Walking and slow jogging will work, but I find if you can keep the speed up a little bit it helps reset your comfortable to a higher level.

How Many?

For the greatest improvements it appears we need between 12-30 minutes of intervals. Exactly how much may be dependant on your current fitness. If you don’t have the ability to maintain the intensity beyond 15 minutes, then there is no point forcing it out to 30 minutes.

If already to some degree of running around VO2max, then start with 4 x 3min intervals. From there you can gradually add time. For example:

  • 4 x 3min (12min)
  • 5 x 3min (15min)
  • 3 x 5min (15min)
  • 4 x 4min (16min)
  • 6 x 3min (18min)

For those who haven’t got a strong running base, have had some time off or haven’t included running at these pace a more conservative start might be better. Starting with 4 x 2min or even less and building up from there would help ensure the connective tissue and muscles are better able to handle VO2 intervals.

VO2 Interval Session

Ideally you won’t be feeling stuffed from previous training. A day or two of comfortable running would be best leading up. Make sure you are hydrated and fuelled lightly. These are not the types of runs to testing out any depletion strategy.

Warm Up

Warm up well. Treat it is an opportunity to fine tune your warm up for races. I like to run easy and relaxed for 10-15min until my body feels ready. Then I’ll either gradually increase the speed, or throw in a few relaxed run-throughs at speed. Nothing is forced, but I am looking feel the natural snap and spring from running faster. Total warm up time is usually 20-25min.

Main Set

Straight into the first interval. The paradox of trying to feel relaxed while pushing up the speed. Aiming to get the pacing spot on at the start. Making small adjustments as to be as exact as possible. Ideally you can hold the same pace from the start through to the end of interval. Then keep up that pace for each interval.

At the end of the interval relax into the recovery. Resist the urge just to stop or walk. Make the most of the momentum and keep the legs moving. Relax with each breath and reset the mind ready for the next interval.

Focus on the key elements of your running stride. Push through the ground. Keep the snap and lightness in each step. Stay away from muscling through. Beware the laziness of the body. It looks for the easy way out in the short term. Keep your technique, speed and power. Teach your body to maintain the efficiency of speed.

Cool Down

Once all the intervals are completed ease into a relaxed jog for the cool down. I like to start super easy and gradually build the pace back up over a few minutes to a run that feels moderate. Then hold that for a further 10 or so minutes before easing back down over a further 5-10 minutes seems to have me feel fresher over the next day than if I just jog easy or do a really short cool down. I have no science to support this. Just years of trying different methods.

VO2 Intervals

  • Warm up 10-15min easy running then 5-10min faster running
  • 4-8 x 2-6 minutes at 95-100% VO2max / 90-100% HRmax / 5000m-3000m race pace
  • Recovery between each interval 2-4 minutes easy run
  • Cool down for 10-20min

Ultra Marathon Training: Block 1 Weeks 1-4

It has felt like years since I really trained fast. With ultra marathon training I’d become pretty good at shuffling my way over long distances. I get a lot out of this, but miss the faster running of my earlier years. So I’ve set a goal that should help me find some of that speed again. Some extra detail is in 2018 Running Goals.


Different and bigger goals require a change in approach. The main difference is a regular inclusion of faster running. The fast running won’t work on it’s own. It is only part of a bigger picture. Let’s break it down.


Block 1 is the first of 5 blocks, each of 4 weeks in my lead up to the Wings For Life World Run. An overview can be found in Training Plan Overview 2018: 7 Steps To Setup Your Running.


There are main 2 points in Block 1:

  1. Increase VO2max
  2. Increase distance of long run

Both these points will extend into Block 2. They should set the base for more specific training in the remaining 3 blocks.

keep on running ultra marathon training

1. Increase VO2max


This is the gold standard of aerobic fitness. A higher VO2max means you can do more work or run faster while using oxygen. It filters down to all intensities below it. Heavily determined by which parents you chose, there is still a substantial influence training can make.


There are a multitude of different ways to train to increase your VO2max. These have different effects on other areas of fitness. I will stick to what has been well supported in research and has worked for me in the past. It is a throwback to my university days when I was a lab rat in many exercise studies.


My go to VO2max training session is 4-8 repeats of 3-5 minutes with 3-5 minutes of easy recovery in between each repeat. The intensity of each repeat should be very close to my VO2 max, which will be about 3000m race pace.



2. Increase Distance Of Long Run


To make the Wings For Life World Run an ultra marathon I need to be able to handle running a long way. That calls for some long runs.


I know I can shuffle out some very long distances. However, the pace won’t get me anywhere near my goal. There is a big difference between 7:00/km and under 4:27/km. This means my long run needs to shift up a gear or two.

The struggle will be to find that balance in going faster versus adding distance.


Training Plan


Over the 4 weeks I was working in 8 training cycles. I know this doesn’t fit neatly, but it works for me. My work roster has a lot to do with it. The planned training for each of the 8 days is:Ultra marathon trining week 1 to 4

  1. Easy – likely a run commute to and from work. Anywhere between 4-10km each run at a pace that is comfortable.
  2. Easy – run commute. As per yesterday, but if feeling okay I’ll throw in some short hill repeats in the morning run.
  3. Easy – again likely a run commute between 4-10km. These first three days are about regeneration from the previous week/cycle of training. I want to come out of these three days feeling ready for some hard sessions.
  4. VO2max Intervals – this is my key “get faster” run. Starting with 3 x 1000m repeats with an easy 600m jog in between, I’ll add a repeat each week. The rest of may day is lazy as I will be following up with a night shift at work.
  5. Regeneration – this day is mostly written off as a nothing day. I’ll be sleeping for most of it after a 14 hour night shift. I hope to force myself to get in a few very easy kilometres of running. Sleep is definitely the priority.
  6. Long Run – Starting with 30km I want to add 2km each week. I expect to carry over some fatigue from the VO2max intervals, but I hope I can get this right.
  7. Easy – just a simple 6-14km to keep the legs moving.
  8. Hill Repeats – I will pick hills that take 2-3 minutes to run at a bit below VO2max pace, with a very easy jog back down. It is a mixture of specific strength and support for VO2max development.

The total kilometres in each period are not a goal. That total will take care of itself if I focus on getting each session right