As the last installment, this final interval post covers every interval not time based.
If you need help getting started, wonder about the science behind interval training, or are wondering what the heck HITT is, check out Part 1.
If you were looking for 9 awesome time based protocols, you’ll have to see Part 2.
This is everything else.
Distance Based Intervals
Distance based intervals, obviously account for distance in their calculation, instead of time, or in some cases, in addition to time.
I like short distances for intervals mostly, but they are incredibly under-utilized in distance oriented endurance sports too.
For instance, there have been many times where I’ve worked with someone who wanted to complete a race in a given amount of time.
Typically the easiest way to help someone figure out what they need to do in their training, is to break down a race into smaller, more manageable chunks of time.
For example, if someone wants to run a 5k race in less than 25 minutes, we best make sure they can run a kilometer in less than 5 minutes, before we worry about adding distance to their training.
In many cases, I would do sub-5 minute kilometer intervals, resting as much as necessary to keep the outcome a sub-5 minute kilometer, then gradually work towards shortening the rest interval until you get it as short as possible, then possibly switch to two kilometer sub-10 minute intervals, and so on.
Distance based intervals are perhaps my favourite personal interval protocols to use because you are capable of constantly looking for improvements.
1. Timed Distance Intervals
These are easy, 100 m for time, or on the rower 250 m for time.
The added benefit is that you get to monitor drop-off in performance, significant drop-offs in performance depending on the amount of rest can often be an indication of when to stop.
Typically you should line up the rest intervals to the appropriate energy system, so the shorter more intense the distance, the longer the rest periods should be.
The metric to monitor is the amount of time it takes to complete a certain amount of distance.
The way I like to use these is to rest either a set amount, or an equal amount to the time it took you to complete the interval.
What I like most about them is that you can easily monitor to maximize performance. If you drop off quickly then you might need to extend the rest, and work significantly on the interval, if you can go forever (more than 20 minutes) then the rest is probably too long.
Generally I recommend that if you drop below about 15-20% of your best performance — typically not the first one, but often the 3rd to 5th one is your best interval — then you’re done for the day, so I won’t choose a set amount of time for this type of interval work, but rather reduced output.
Run 100 m, record the time, rest, and repeat.
Row 500 m, record time, rest for the exact same time it took, and repeat.
2. Distance-Based High and Low
Rather than going for a certain time, these intervals use distance as the measure of high intensity work and lower intensity work.
Like their timed counterpart, you have a period of high intensity work and a steady period of low intensity work.
Distance is the only thing that is important in this type as a unit of measure, but is also a nice way to mix things up.
Running around a track, every time you hit the 300 m mark, you sprint for 100 m, then light running, walking or striding for 300 m.
Another might be found in a 2000 m row, whereby you row as hard as possible for 200 m — you could even say in this case, take your stroke rate up to 32-33 strokes per minute and hold a certain wattage — and row lightly for 300 m — or hold a steady 25 strokes per minute at a low certain wattage.
3. Distance-Based Start and Stop
This type of distance based interval might be all out sprints, but you rest a given amount before starting up again.
The game ‘Red Light, Green Light.’ Which is kind of an example of Fartlek training too, mentioned below.
Many deceleration drills are like this and can be visual (hand) or audio (command) oriented, in which you try to force someone to learn how to stop efficiently within a certain distance or at a certain distance.
Sprint to a line, and try to decelerate as quickly as possible after that line for time, would be a good example too.
Rep Based Intervals
Rep based intervals can be timed or you can explore other ways of utilizing reps to track progress like two of my suggestions.
Obviously reps are used as the unit of measure here.
1. Timed Rep Intervals
Can be done as circuits or as timed rep-oriented sets. I briefly discussed these already in part one from a time perspective.
These often blur the lines between energy system work and strength endurance training.
It’s important to pick a rep range that you can do relatively easily (i.e. you have a few reps left in the tank on the first one or two intervals) to maximize endurance gains.
Once again there needs to be some kind of rest interval for this to be considered a rest interval, so 100 push-ups for time, is NOT considered an interval protocol.
Activities like burpees, air-squats, double-unders, jump chins and other high intensity conditioning activities done at higher velocities seem to work really well for these types of intervals, just keep the reps reasonable, under control and away from too much fatigue. I hate box jumping for high reps and you should too.
My biggest criticism when I see these types of intervals in action, is that the reps are too high for a person’s given skill level, so don’t be afraid to modify for your needs.
25 push-ups for time (make sure your chest hits the floor and arms extend), rest 60 seconds, and repeat. When you see a drop-off in performance (20%) you can probably call it a day, let your body adapt in recovery.
2. Max Reps per Time Intervals
Again, discussed more at length in part 2.
These intervals are often just a period of time, you do the max number of reps you can in that time, then rest for an allotted period of time, and try to beat your previous score.
This could be something simple as max number of burpees in 30 seconds, rest 30 seconds, repeat.
The key to these intervals is that you track your max number of reps, and try not to drop below, because at the end of an interval training session, you gauge progress by taking your lowest number of reps in the given amount of time.
Again I like to use these because it is easy to monitor progress, but also a drop-off in performance, which often means not much will be gained by continuing if you see too much of a drop-off in performance.
In Crossfit (why the hell am I still referring to XFit??), this is how they score the workout Tabata This or Tabata Squats.
You track how many reps you complete in the 20 seconds, get 10 seconds of rest and repeat for 8 rounds — until in Tabata This you move onto the next exercise, or Tabata Squats, which are a nice quick interval training protocol.
This can be done with any interval protocol, but I also really like using it with the Little Method and the Boutcher Method I mentioned in part 2.
3. Time to Completion Rep Based Intervals
This is very similar to the max reps per time interval protocol above, but you don’t worry about taking the lowest score.
For these I just monitor that 20% or so guide again, once you see a 20% drop off in performance from your best rep-based-interval, you should probably call it a day and get to the recovery part of the workout.
Unbroken Rep Based Intervals
Unbroken Rep based intervals, are merely the attempt to achieve a certain number of reps before you reach technical failure — the moment in which you cannot complete another perfect rep, NOT the moment in which you completely fail — this is really just sound muscular endurance training.
You do as many unbroken reps as you can, rest the predetermined amount of time and repeat. Basically it’s training to muscle failure repeatedly.
Heart Rate Based Intervals
Let me start by saying that there are probably a bunch of different ways of using heart rate intervals for very specific end results. Most however, require some formalized endurance testing via metabolic cart. If you’re not serious about endurance performance (i.e. you’re some kind of endurance athlete), I think metabolic testing is probably overkill.
We can however estimate your zones and I think heart rate based intervals are one of the most practical ways to do aerobic and glycolytic training. The downside? It does require the purchase of equipment… A heart rate monitor…
A heart rate monitor is the only way to really guarantee that your rest intervals are sufficient and we can monitor how your heart is actually adjusting to the training by paying attention to how long that takes after each work interval.
It is generally acknowledged that you have 5 different distinguishable endurance training zones based on heart rate and depending on other tests like lactate testing, lung capacity testing, infrared muscle testing, etc… you may require certain amounts of training in different heart rate zones to optimize your training.
This is really really advanced, so unless you’re a competitive endurance athlete, it’s really beyond the scope of this article series.
For our intents and purposes you can estimate by using percentage of heart rate max — a little over-simplified and not necessarily accurate particularly if you’re fit — or you can use Heart Rate Reserve (HRR), which is generally a little more accurate a method, but still not as accurate as going into a lab to get this tested in association with your lactate levels, aerobic threshold and anaerobic threshold.
The following intervals are really a lot more cut-and-dry, because it mostly makes a big difference if you’re an athlete who competes at a relatively high level in my opinion and this is your limiting factor — things like lung capacity, strength, power output, technique, etc… could also be limiting factors in energy system performance.
However, I like to write stuff that appeals to the other 80-90% of the population with little to no previous training experience.
1. Heart Rate Recovery Intervals
Are based off of heart rate, rather than time/duration, reps or distance.
You can run off percentages you discover above, like move up to 80% HRR, then allow yourself to back off until you hit 60% of HRR for instance.
Or what I like to do is get your heart rate up to something that feels comfortable, give yourself 5 minutes, should feel like you’re working at a 6 out of 10 effort.
Record that heart rate as your recovery target.
Then max your heart rate through high intensity training, you’ll know when it begins to burn too much you cannot sustain the intensity and must rest, or your heart rate peaks and doesn’t change for a longer period of time — 10-40 seconds generally but this depends, it may take at least 2 minutes in some cases to really tax the glycolytic system and for your heart rate to find a steady ‘peak.’
What ever number your reach at the high end is your target from now on, most likely subsequent intervals will send your heart rate higher, so stop when you hit that max you’ve determined, lower the intensity and allow your heart rate to return to your ‘recovery target’ before you attempt to max out your heart rate again.
As you get better at interval training in this method, you’ll obviously you’ll be able to hit higher and higher levels of max heart rate (up to a point…), so adjust accordingly and don’t forget to switch things up when you start to plateau either in your recovery zone or your max zone.
Obviously, this is a slightly more advanced interval training protocol, but it can be great for showing people just how high an intensity they can tolerate — you’d be surprised!
*If you have a pre-existing heart condition, please don’t attempt my method without clearance from an exercise physiologist or your doctor.*
Discovered that my comfort zone heart rate is 140, so I max my heart rate out to 195, then slow the intensity down until my heart rate returns to about 140.
Sometimes this includes having to stop completely, other times it means working at a very slow intensity for a while, in which case you may discover that you feel great at a higher intensity level for your rest period.
You might also have to play a little with the numbers as after hitting your max, your heart rate recovery might not be all that great and getting down to 140 again will require completely stopping and walking for now, or slightly increase your recovery zone if you feel like you won’t drop below your estimate.
I like to go by feel on the rest interval for the average ‘weight loss’ client, but you can also use formulas or a metabolic testing scheme if you like being technical.
2. Heart Rate Zone Intervals
These intervals would be based off the notion of keeping your heart rate in a target ‘zone’ for a period of time.
Typically I want it to be at or near your lactate threshold (or a tempo pace) so they should burn a little as you finish them up, if they don’t then the heart rate zone probably wasn’t accurate enough.
There are 5 commonly accepted ‘Heart Rate Zones,’ that I won’t get into here. If you had a formal test you could even adjust your interval training to hit various zones in a more random like fashion, as in the Fartlek training method described below.
Hold 165 BPM for 2 minutes, allow your heart rate to drop to 140 for 1 minute and repeat. You may have to experiment with this one if you do not have access to a testing/training lab.
Fartlek means ‘Speed Play’ in Swedish, and is designed to mimic the randomness found in all sports.
This type of training could be random heart rate based training, random distance based, random time based, or a combination of all of them.
These interval sessions usually last much longer than I would normally recommend — 20-30 minutes max for higher intensity intervals — but usually make someone go in and out of anaerobic and aerobic energy systems.
It could be sprint for 2 minutes, walk for 1, side shuffle for 2, walk for 3, backboard touches for 30 seconds, walk for 2, burpees for 1 minute, suicides for 2 minutes, shoot 2 free-throws (a basketball example…), backpedal for 1 minute, walk for 1 minute, etc…etc…
I typically only use these in sport training environments, as the S.A.I.D. principle applies, so the best example of using this style of interval training would be simply ‘game play‘ in power sports.
I honestly don’t believe much in deliberately planning a random training session whereby I might take a hockey player and make them run a fartlek training, even if it mimics the 45 sec to 2-3 minutes rest intervals found in hockey that they might otherwise encounter on the ice.
It would be better to run them through that conditioning on their skates, on the ice, without the contact found in games.
A great way to utilize these is in the phase leading up to a camp or pre-season, utilizing a few more ESD days than usual to bring an athlete up to game speed, and prepare them for the energy system demands of their sport.
In endurance sports, this is can be utilized a little bit more. It can also be mimicked by simply picking challenging and unknown routes via hills, obstacles and other challenges like changes in surface.
Also published on Medium.