Training Zones Explained

photo by AngryJulieMonday, (CC BY 2.0)I think it is time to give you all a little more insight into how I establish training zones and the purpose of each training intensity (level or zone). I won’t bore you with physiology but will get the salient points across as clearly as I can without using too much jargon, so here goes:

General: The cardiovascular (hearts, lungs, delivery system) and muscular system will improve if given sufficient stimulus to create a response or adaptation. The body though is very smart and will only adapt to a level of efficiency sufficient to cary out your bidding. If you cease to change the stimulus you will cease to improve your fitness.

Swim – I use a concept known as CSS (Critical Swim Speed) to set your training intensities in the pool. It is typically calculated using a 400/200 time trial. It is important that you execute each element of the test set at your best possible average for the distance without a catastrophic fade in speed. It gives us a close estimate of your Lactate Threshold swim speed. Unique to swimming is how fast your form breaks down and compromises your ability to otherwise hold your training paces so do be mindful of this during longer harder main sets and if necessary insert a short drill set such as 4×50 corpse drill and then get back to the main set with renewed focus and an enhanced body position. *With its high skill requirement and need for ‘feel’ swimming will rarely progress unless you are in the water three or more times per week.

Bike – We use a benchmark known as FTP (Functional Threshold Power). It is easily calculated with an FTP test such as the ten mile TT we use at the Performance Center or a T30 (30 minute best effort) which is something we typically perform out on the road to validate our indoor numbers and/or when more appropriate as the weather improves and the race season gets closer. *It is key that you execute the test in the position that you intend to spend the majority of your ride time during your races which for most of us is in the aero position. Muscle recruitment is different in the aero position than in a more upright riding position like resting on the base bar. You have to park the ‘ego’ when testing and understand that a bigger number is not necessarily a ‘better’ number!

Run – We can essentially use any test distance from one mile to a marathon to determine run zones, the only key is that it is from a recent performance. Periodically I like my athletes to perform a ‘test’ in the form of a race so as to ensure sufficient motivation and co-action to bring out the best result. If a suitable race can’t be found a short (2 mile) time trial can be used. I tend to use the Raceday Apollo zones and the Jack Daniel’s zones interchangeably, the good news is they correlate against each other quite closely.

Here is an explanation of the training zones as laid out in Raceday, where relevant I have added the Daniel’s description…

Zone 1 – Recovery (slower than any of the Daniel’s zones). Used mainly for warming up, rest intervals during intervals and cooling down. Can also be used for active recovery sessions. Creates little to no metabolic stress, will elevate HR a little but force of contraction required is very low.
Zone 2 – Aerobic Zone (Easy Pace or E Pace). This training pace can seem slow at first depending on your relative ability but as your fitness improves it will quickly catch up. It is essential you do not stray above this intensity when asked to execute a workout at this speed/effort level. The adaptations the body achieves at this intensity are critical to your future run development and if you over reach you run a high risk of breaking down, getting inured or of simply impacting other workouts within your micro cycle. Increasing the oxygen carrying capacity of the blood and mitochondrial volume in the muscle, improving tendon strength, increasing glycogen storing capacity and the bodies ability to access those stores are just some of the benefits of spending time in this zone. In short it provides the base essential to support higher intensity training and is critical for those of you without many years of aerobic training under your belt.
Zone 3 – Tempo Zone (M Pace or Marathon pace). Now this is still an ‘aerobic’ zone and as such will provide many of the same adaptations as Z2. it is also specific to the level of effort one can sustain for the Marathon distance assuming appropriately trained and correlates closely with 70.3 pace for us triathletes (again assuming training has been appropriate and no errors in pacing and/or nutrition have been made). It allows us to create more fatigue than an E pace run and can therefore help us create the necessary fatigue to force an adaptation in a shorter period of time than might be required at E pace. it can also given the right circumstances (as can Z1) help us promote metabolic efficiency. Often misleadingly time spent in the tempo zone was called “junk mileage” mostly because at a very fundamental level you are working harder than necessary to get all the adaptations from Z2 and not hard enough to get any of the favorable adaptations from working at Z4.
Zone 4 – Lactate Threshold (T Pace or Threshold Pace) is a key fitness marker. Training at this intensity will promote multiple adaptations to the body but key among them is your ability to break down and clear the accumulation of lactic acid and convert it into a useable substrate. Training our bodies ability to efficiently break down this by product of exercise can help us increase this key fitness parameter and bring it closer to vo2max as a % which is critical to success in endurance sports. It hits most of the key metabolic adaptations in one intensity the flip side is it also puts great demand on the musculoskeletal system so needs to be used sparingly early in your athletic development.
Zone 5 – VO2Max (I Pace or Interval Pace). Represents the % of oxygen you can extract from the air that you take in. The higher the number the greater your athletic potential. It can influenced by training and this is why we spend time performing a block of work at this intensity. It is not for the feint hearted (or those new to endurance sports) as a certain amount of discomfort comes with work at this intensity. The rate at which you are forced to breath and the muscles contractile force is high, the extraction rate of O2 needs to high in order to sustain work at this level hence when forced to do it your body becomes more accomplished.

It is important we try and correlate the above intensities against perceived effort (PE), Heart Rate and Power/Pace. It is also key we understand that the relationship will change as climate and conditions change and exercise duration increases. It is my goal to ensure you all use the feedback mechanisms you have available and that you spend time dialing in your own perception of effort. These skills are key to your development. Don’t be a slave to the garmin/power meter but do use it to ensure you are not ‘over working’ or slacking off.



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