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Whats it Zone about then.

For those of you who are new to it, it can seem like a foreign language. Terminology like functional threshold, critical power, zones or VO2 max may have little meaning to you, but the more you want to get from your training, the more these instructions and phrases will matter.

We train to improve. In order to do this your training needs to be specific to generate the required adaptation, simply going for a run or ride is unlikely to be the best use of your time.



Because different intensity of training have different effects, we need a way to classify how hard we are working and what effect it will have. Hence training zones. A training zone is shorthand for describing how hard we should be working during that particular training interval/session.

At reorgfitness we use 7 (or sometimes less) training zones, to understand the impact of each zone, we need to think about how the body works. (simplified) we have two energy supplies – our aerobic system and our anaerobic system, and most of our training will be focused on improving the maximal capacity of both.

When we ride or run at a nice and steady pace, we are using our aerobic system – it’s easy to keep going and it doesn’t feel that hard. As we start to increase our effort, our breathing becomes harder and we begin to access our anaerobic energy supply – the effort becomes harder to sustain. It is these changes from one system to the other that we mark with training zones. The tipping point between these two energy systems is known as the ‘threshold’; below the threshold is the pace we can sustain over a 60 minute period and is our ‘Zone 4’ or Z4 to use its acronym. Training below Z4 is in our aerobic state and above it is in our anaerobic state.



Zone 1: light spinning of the pedals or jog at a low intensity with no real training response from this intensity alone. This zone is generally used to loosen the legs on recovery days or between interval reps or sets.

Zone 2: the classic, long, slow distance run or ride (or LSD as it’s known in training lingo). All-day pace intended to improve aerobic fitness and basic endurance. It will feel easy with little concentration needed to maintain pace. You will notice an increase in breathing over Zone 2 (AeT). A good test that you are still in it, however, is that you could easily maintain a conversation.

Zone 3: is more a spirited or briskly moving pace, improving aerobic fitness and endurance more effectively than in Zone 2 and comes with associated higher training stresses or fatigue. This intensity can require some concentration to maintain especially at the higher end of the zone. You could still hold a conversation at this level, but it will be broken for you to manage your breathing.

Zone 4: this is where we reach our threshold level (AnT) and the zone goes from just below, or Sub-Threshold, to just above, or ‘Lactate Threshold. This intensity is intended to improve your sustainable pace and also act as conditioning for higher intensity speed work. At this intensity, sensations of fatigue are moderate to increasing with sustained conversation difficult due to the depth and frequency of breathing.

Zone 5: it’s now starting to feel more difficult and Zone 5 is typically where you will see your training program requiring you to hold longer intervals of efforts (3 – 8 minutes). The intention is to improve ‘maximal oxygen uptake capacity more commonly known as VO2 Max). It will also help to improve your maximal sustainable pace and will be accompanied by strong to severe sensations of effort or fatigue. You’ll know when you’re in this zone as it’s unlikely that any conversation is going to be possible!

Zone 6: is very hard and is generally the intensity of shorter intervals (30 seconds – 3 minutes). This is high intensity work designed to increase anaerobic capacity and your real top-end performance. You’ll experience severe effort and fatigue, and let’s face it, you’re not going to be talking much here either. To hit your Z6 right, make a mental estimate of the maximum power output you can hold for the timed interval, start at that rate and do your best to hold it – no fading before the end.

Zone 7: it’s short – high intensity standing starts and sprints that generally place more stress on musculoskeletal rather than metabolic systems and is designed to increase maximal power and speed. This is maximum pace, cooking on full gas for the duration! If your training program asks for a Z7 effort, it means we want you to go all out from the saddle as hard as you can without even thinking about the duration. Chances are, you won’t be able to hold the pace for much more than 10 seconds – so if the interval is timed at 30 seconds just go eyeballs out for the first 10 and see what you can hold until the end.



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