A new take on interval training?


Ever wondered why you work really hard but seem to go nowhere?
This could be part of the answer

A recent study showed that when 2 groups underwent VO2max training it was the group who were prescribed slightly shorter intervals at VO2max speed that came out on top.

Group 1 were asked to complete intervals of 60% Tmax, (Tmax being the time they could hold THEIR Vo2max speed till failure) improved far greater than the 70% Tmax group.

Why was this? It's not instantly apparent, but when you delve into the study you find the 60% group actually completed MORE time at VO2max pace than the 70% group, completing 96% of the interval time per session they were prescribed, compared to the 86% in the 70% group.
So, each session the 60% group spent on average an extra minute at this pace.

This explains how the 60% improved more over the 4 weeks. Physiologically this is explained by an improvement in running economy in the 60% group (3.3% compared with 0.8% in the 70% group) and a huge improvement in Ventilatory threshold int he 60% group (6.8% compared to 1.7%).

Why did this happen? Its likely related in part to the increased amount of work the 60% did per session. But I also think the increase in economy is related to the fact that the 60% stopped the interval BEFORE they were to fatigued. This is great for running economy as the one thing running economy hates is when fatigue builds up resulting in a loss of technique and damage to the neuromuscular control (I will be covering this in a whole series on running economy and why you should care about it, ALOT!).

What can you do with this to enhance your training? Firstly these results show that significant improvement can result very quickly with high intensity training, so its worth including in a training plan.
Secondly, if you are going to implement these sessions its worth paying attention to how much work (the interval part) you are completing in each session. In this study the participants were completing about 13 minutes hard work. For VO2max and running that is about right. Aiming for 15 minutes is a good target. If you are only able to complete 10 minutes or less you could be going too hard and possibly too short.
The runners in this study had T-maxs of around 4 minutes, so were completing intervals of 2-2.5 minutes long, with a work rest ratio of 1:2.
This is about right for running (but too short for cycling, in running you ramp to Vo2max faster due to you having to support your body weight and using more muscles).
And aim for around 6 or 7 of these.
If you are failing at 5 you are going a little too hard. But, the best way to find this pace is to test yourself and see how fast you can run for around 4 minutes (it may take a few goes to get the pace right).
The work at this pace for around 2 minute intervals, or 2.5minutes if you have been running/training for a good few years as your capacity to hold VO2max pace will likely have increased.

Keep a check on how much work you are getting done each week at this pace. If its not going up then you may need to change things around, either running faster or running slower for slightly longer.

Hope that was interesting!