Saturday, October 26, 2013

Lab Results - interpretation and follow-up questions answered

No running today - another rest day!

As promised, here are my notes that I took following my recent VO2 and lactate threshold testing. Many thanks to Paul McNamara for his time in conducting the tests, plus the follow-up interpretation of my results. I also asked a few questions to Paul and his answers are noted below.

Basic Results

There are two lactate threshold readings which are key in measuring running economy. These are LT1 and LT2:

LT1 – 15.2km/hr (3:57/km) @ HR of 140 - a lactate level just above baseline. In other words, to train above this intensity then lactic acid in the blood will start to rise. This results shows I have a high percentage of type 1 fibres (slow twitch). This is my easy run pace. A good idea to run an hour at this pace every few weeks as a session during training.

LT2 – 17.6km/hr (3:25/km) @ HR 161 – my tempo run pace. The pace I could maintain for 1 hour. Above this pace lactic acid is produced at a markedly quicker rate than the body can clear it.

VO2 max (ml/kg/min) – 64.4 (VO2 max pace of 3:06/km @ HR of 169) – this reading is more relative for comparison purposes as it factors in body weight.

VO2 max (L/min) – 5.043 – the maximum amount of oxygen my body can process per minute.


Basic training principle - to improve LT1 and LT2 (your running economy - to shift your lactate curve to the right) I need to focus on running at LT1 pace for my easy runs, and at or below LT2 pace for my tempo sessions. Typical tempo sessions would be:

- 20 minutes continuous effort at 3:25/km pace @ HR 161
- 6 to 8 x 5 minutes off 1 minute at 3:25/km pace @ HR 161
- 6 x mile off 60 seconds at 3:25/km pace @ HR 161 (equivalent to 5:29 per mile)

Over time you should be able to increase the pace of these runs but still be running at the same heart rate. So the objective for me would be to say improve my tempo run pace to 18km/hour or 3:20/km pace at the same heart rate of 161.

It's key to decide on an objective for each speed session. If it’s a threshold session, then maybe select one of the above. If it’s a VO2 type session (quicker running), then maybe cut down the duration of the efforts to say a maximum of 1km, but run them at a quicker pace. More on this in my questions below.


1) If you decided to run a longer continuous tempo effort, say 30 mins or 40 mins, what pace/HR should that session be at?

Good question – as a good rule of thumb, allow 2/3 secs per mile for every 5 min of running beyond 20 min. E.g. if you’re running 5:30 per mile (3:25/km) for 20 min of tempo, I would do a 40 min tempo at approx. 5:40 per mile (3:31/km). Even though the pace is reduced your HR and blood lactate will both slowly rise to that expected at LT. If you were to maintain 5:30 miles for the entire 40 min then HR and Blood lactate would likely climb well beyond true LT intensity, and the training load might be too great.

2) What pace should you run for shorter intervals – say 400/600/800 for both 5km and 10km training?

Again, this depends on the objective of the session. If the purpose of the session is to enhance VO2max, or to improve running velocity at VO2max (which is more beneficial) than any pace between 3k and 10k pace would suffice, but 5k pace is optimal. Along with pace you can manipulate the volume of the session and the duration of the recovery for the desired effect. E.g. a classic session might be 16x400 at 97% VO2max (approx. 5k pace) with 200m jog recovery in the same time. Many athletes do this session too fast, with too generous a recovery, which serves to emphasize anaerobic capacity and results in too high a training load. With classic interval training the objective is to improve the rate of recovery.

However if the objective of the session is to become accustomed to running at race pace, than a repetition session might be more appropriate, E.g. 6 x 1k at 5k pace with 3 min recovery, or 6 x 1 mile at 10k pace with 2 min recovery. The emphasis here is on the work-out, rather than on the speed of recovery, so more generous recovery periods are allowed.

On the other hand if you want to work on speed, you might do short repeats at 1500m pace or faster, but with generous recovery. In fact if the focus of the session is on running fast than you should probably allow full recovery. E.g. 10x300 in 45 sec with jog 300m recovery. HR is only relevant in this type of session to gauge how quickly you’re recovering.

If you want to develop anaerobic capacity, or lactate tolerance, than fast efforts with much reduced recovery would be appropriate. You could do this in sets in order to manage the training load, and to accomplish greater volume at this higher intensity. E.g. - 4/5 x (600m @ 1500m pace, 30 sec recovery, 200m fast), 3 min between sets.

3) What are the benefits for me training at a pace above my VO2 max pace of 19.4km/hour (3:06/km)?

Again – we have to ask what the purpose of the session. Both speed and lactate tolerance are relevant for all endurance events and have a place in the training programme - but they become less of a priority as race distance increases. These are critical for 800/1500 athletes, but priority for 10km to Marathon should be a high lactate threshold. For 3k/5k a high running velocity at VO2max is critical. All of these sessions are relevant for all distances, but each will receive a different priority weighting based on the athletes target distance. For you, I would include this type of work – but I would be cautious with it. If doing interval work to boost aerobic capacity than I would avoid exceeding the intensities associated with VO2max.

4) Over what time period can you improve your lactate threshold?

Surprisingly quickly. Although the best progress is slow progress, you could see a marked improvement within 6 weeks off just one LT session per week

5) My current LT2 is at 88% of my VO2 max. What can I realistically improve this too? Is there a rule of thumb?

Efficient athletes can bring this up beyond 92%. I was once measured as having an LT 95% of my VO2max

6) What pace should long runs be at?

LT1 (HR or velocity) is a useful ceiling for long runs. However, as with above, long runs can serve many different purposes, particularly if training for a marathon. For your classic long, slow distance, than any pace at or below LT1 will serve to recruit exclusively type I muscle fibres and enhance their efficiency.

7) Would you incorporate one LT session and one VO2 session into weekly training?

Depends to a large degree on the training phase, target race, etc. But for the most part these 2 sessions are the bread and butter of most long distance runners training week. I would generally do a VO2 session on a Mon, LT session on a Thurs, and a long run on Saturday.

So there you have it. Time for me to buy myself a heart rate monitor - though I might wait until the new Garmins are released in the next few weeks! If anybody has any questions or feedback then I'd be very happy to follow-up on any points raised.

1 comment:

Scott Brown said...

I'm jotting this down! Thanks for posting it, it is very helpful. Cheers Matt and all the best in getting the knee sorted.