Threshold has been all the talk since the Norwegians have been on the scene. All they seem to do is threshold training and maybe thats what makes them so good. There is no doubt that training at threshold is extremely valuable for fitness and performance, but weighing the risk of fatigue vs the benefit of threshold is something many often get wrong.
What is threshold?
Threshold, lactate threshold, aerobic threshold, LT2 are all similar terms for the same thing: the maximum intensity that can be sustained for approximately 60 minutes. Another term is maximum steady state and it can be defined officially as the upper limit of intensity whereby lactate can be cleared by the body. Below this threshold is quite comfortable for most and can be held for a lot longer periods. Whilst anything above this threshold is very hard and fatigue will creep up on you a lot faster than 60 minutes. This is the last the point at which our production of lactic acid and other metabolic by products is equal to our clearance, therefore above threshold we begin to accumulate these nasty by products which gives us that burn feeling in our legs and lungs. At our threshold we are working quite hard, often around 85-92% of our maximum heart rate. It is also trainable meaning you can shift the range slightly, or, improve tolerance at this intensity.
On the bike, ‘threshold’ is often calculated via a ramp test or an FTP Test. From a ramp test, 75% of the best one minute power is taken as your threshold number. For an FTP test, 95% of the 20 minute power output is taken. FTP is said to be at or just above your threshold as many of you will have experienced. Threshold in swimming is quite similar however it is rare that we swim for 60 minutes straight so we often use ‘test sets’ such as 3×300 or CSS testing to determine a ‘threshold’ value. Likewise with running, it can be quite invasive to complete a 60minute running test which is why a 20 minute test or a 5km run can provide your approximate your threshold heart rate and/or pace.
Our threshold values are what we record from our many rounds of testing and what your coach will input into training peaks to ensure all of your training is set appropriately.
How is it Used?
Bike – often measured using power or a combination of power and heart rate. Be aware that changing cadence will change your heart rate response even for the same power output
Run – Pace or Heart Rate Zones
Swim – Pace per 100m
Why do threshold training?
As mentioned threshold is highly trainable. We can push up our threshold by training around the threshold zone. As endurance athletes, we want to go faster for longer, so training threshold can be a valuable tool to achieve just that. What once was quite difficult to hold for longer than 60 mins might become just that little bit easier.
It is however very taxing on the body for most of us. Particularly those ultra-endurance athletes amongst us! It takes a significant amount of energy and creates a signifiant amount of fatigue to train at threshold. These sessions are ideally completed with full nutrition and hydration preparation beforehand, during and afterwards. Aim for 60-90g of carbohydrates and match the fluid to your sweat rate for optimum results and optimum recovery.
Keep in mind that whilst threshold training is great, we can only improve from the training in which we recover from. If it fits around the rest of your training, its a big tick coming in to race phase.
Ryley Pasquali
BSc, DPT
Photo: Matt Ellis might have been pushing threshold to get up the Matthew Flinders hill at Port Mac!