The Value of Intervals for Distance Runners

I am sure the most runners out there know that as they approach key events that they need to add speed and one of the common methods employed is intervals.

Intervals are a series of efforts run at speeds faster than normal training with a rest interval (usually a walk or slow jog). These are an obvious stepping stone to developing speed but what sort of intervals should you do? Also when and how much? The final point worth considering is the length of recovery between intervals and how hard you run/walk between.

Types of Intervals

Very Short Floats
These are typically 100-200m efforts and can be very good for working on leg speed and also for pre event warm ups. Running these at race pace can feel really easy and leave you feeling ready. I like these in taper weeks and also in easier weeks as a way to 'wake the body up'. It is common for runners to feel lethargic as they cut back on their volume especially those coming down from 100+km/week and these are very effective for this.

Caution: Do these too fast and they are not specific for your event and you run the risk of injury

400m efforts
A common trend in European athletes are high rep 400's that is 15-25x400m at 10,000m pace. Is this more effective than say 8x1000m? Well the 400's (if run in a controlled manner) don't leave you as taxed, yet you can cover a great distance at or near race pace. It is hard to cover the same distance at the same pace in 800-1600m reps hence the value. However they are not as close to race distance and therefore don't improve your ability to sustain speed for distance (obviously an important element for distance events!)

Generally as you get fitter you will be able to do more of these and with a short rest interval. I think these short distance repeats are better for less experienced distance running (not as far, so harder to do yourself damage).

400m efforts are also good when used in the taper, they can provide your body with a short reminder of what is in stall with out doing any damage that will slow you down on race day.

Caution: Don't run the first few too hard, be realistic about what you will be able to do in the last few. This is a reason to do say 5x400m set with a conservative time (say 5000m pace for the first two weeks before launching into higher rep numbers for 6-8 weeks.

800-1600m effort
The typical distance used these days by distance runners. You do have to still control the speed for the first effort but when done correctly these produce great results. Note that longer efforts are more taxing not only on your muscles but also mentally. So it pays to do these with other runners if possible, just don't get sucked into running too fast with other runners, stick to your plan.

1600m Plus efforts
These are essentially mini time trials. I think there is a lot of value in doing 3-5km runs at 10km race pace in the weeks leading into a 10km effort, there is nothing like a 5km race to lift your pace and help you to hold sustained speed.

Caution: These can be very damaging and may take a few days to recover from, especially if done on concrete or asphalt. Make sure that you include a recovery day or two and try to get onto soft surfaces for these runs.


Mixing distances
Consider mixing distances starting with say 2x1000m and then switching to say 5x400m at projected race pace. This can be a lot easier to handle than doing 4x1000m or 10x400m. Pyramid sets are also a good way to break the boredom of repeats. For example you could run a 400-800-1600-800-400 set.


Progressions
There are two key progressions for speed firstly the obvious easy to hard progression that should be planed through your 3-4 months leading into an event, indeed there should be a steady and gradual progression throughout an athletes career. This is one of the best reasons for using a training log that allows an athlete to review previous amounts of speed (by week and month).

The second type of progression is from short reps and/or short total distance at projected race pace through to longer reps at or near 50-80% of race distance.


What speed and What Rest Intervals
How long should your rest intervals be? Well I believe that athletes when planning their buildup should consider what their expected speed will be in their goal event (projected race pace) and this is the speed that intervals should be at. So say that your goal projected speed for 5km run is 18km/hr you should run your speed intervals at 18km/hr then depending on the rep distances you choose the rest would be the shortest amount that allows you to fully recover to run ALL the reps at project race pace. So in this case if you chose 400m efforts you would be running these in 79-80s (the first few would feel slow) and you would probably find that you only needed 30sec rest to be able to complete a set of 10 of these that is how much you would take. Obviously you will need longer rest to be able to apply this to longer efforts at projected race pace. Another way to gauge the rest interval is to start each effort after you have reached a pre determined heart rate. I like to use 50 beats below the heart rate used. So if I am finishing at a heart rate of 170 I will start the next interval after I reach 120 in a slow jog.


VO2 Max Training
In recent years there has been a lot of discussion regarding training at higher speed than projected race pace and one way of describing this is in terms of the velocity that produces VO2 Max. This is simply running at the pace that results in you transporting the greatest amount of oxygen possible to your running muscles. Typically this is slightly faster than your 5000m best time.

This type of training is best left to elite athletes who will generally have a few good years of speed training and racing behind them. To date I have not seen any evidence that convinces me that this type of training is better than running at projected race pace. Except if you are going to run tactical 5000/10000m events such at the National champs in which case this type of training is simply specific training for the sustained push that is typical on the last lap of a distance event or for surges during an event.

About the author of this blog post
Since taking up Endurance Training back in 1984, Coach Brendon, head coach of Endurancecoach.com, has been a leader in the development of the art and science of triathlon and endurance sports training, competition and coaching. He has held many top coaching positions including: Olympic Triathlon Coach 2004; New Zealand Elite Team Coach 2005; Consultant Coach to the Chinese Olympic Triathlon Team 2006; Member TriNZ High Performance Commission 2002-2005; Triathlon New Zealand High Performance Coach; Consultant Coach to Polar International. Many athletes trained by Coach Brendon have achieved podium success on the international sporting stage.

His personal sporting achievements include: 1990 New Zealand Commonwealth Games Triathlon Team; 1991 New Zealand Triathlon Champion; 1993 6th Ironman New Zealand and 8:59 at Ironman Canada; 1994 New Zealand Elite Team Member; 1998 2nd New Zealand Sprint Champs. Coach Brendon has a New Zealand Prime Ministers Coaching Scholarship; Level Two Triathlon Australia Coaching Accreditation; Level One Triathlon New Zealand Coaching Accreditation; Bachelor of Science degree and a Post Graduate Diploma in Physiology.

Endurancecoach.com believes that every athlete is different and therefore needs a training program geared specifically to their personal ability, taking into account any weaknesses, time available and circumstances. Endurancecoach.com offers a variety of services ranging from one-on-one coaching to training plans for specific events and races. Visit Endurancecoach.com for more information or if you are looking for world leading coaches to assist you, e-mail Endurancecoach.com at info@endurancecoach.com.

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