By Selina Campbell, PhD
Let’s face it… we all have a lot going on in our lives so when we can get a workout in we want it to count – we want a ‘good’ workout. But what exactly constitutes a ‘good’ workout? One that gets you hot, sweaty and tired muscles, or one that progresses your fitness? They aren’t necessarily the same thing.
Here at TCR we are seeing more and more people coming in on the edge of burnout. They have spent nearly 3 years sitting in their basement hammering on zwift and they are tired and experiencing drastic drops in their threshold. So, how to we reverse this trend? Back to the ‘train like a Norwegian’ from our last blog post!
The upper end is easy to nail – everyone can go hard! Where we, here at TCR, see people fall down is on the lower end and that is where you should be spending 80+% of your time so it is vital to get it right!
We have a super simple way to establish how ‘easy’ your easy should be with our LT1 testing. The protocol is super easy – do a chill warmup, start pedalling on our Velotron in the lab at 100w or so below your threshold and every 3 mins we do a small finger prick to measure blood lactate levels and then increase the power by just 15-20w, until we see an inflection point where the rate of blood lactate starts to markedly increase (happens around 2.0 mmol/l – exact number is different for everyone). That point is termed LT1 – your aerobic threshold and the level below which you should be doing 80+% of your training.

Case study 1. LT1 (aerobic threshold) occurs between 120-140W. This rider’s FTP is 230W

Case study 2. LT1 (aerobic threshold) occurs between 140-160W. This rider’s FTP is 240W. Note the initial high lactate readings which occurs with riders who need longer warm-ups to engage their body’s lactate buffering system.
From the lab test you will get the HR range associated with this aerobic threshold power (or speed if you do it on the treadmill) and that is what I like to use when I coach my athletes. Power/pace for the top end – pure output numbers. But for your aerobic development you need to keep the workout low stress and HR is the best guide for that. Think of the amount of stress your body can handle in ‘units’ and let’s say at LT1, that is equivalent to 7 ‘units’ of stress on your body. Now, if you are lying on a beach in Hawaii and your only stress is where your next Pina Colada is coming from, then you may be at a ’1’, leaving 6 units free to come from your workout – so your body can handle a higher input (pace or power) to reach that level. But think about your everyday life… 1 unit of stress from lack of sleep, 1 from the kids playing up, 2 from work and 1 from poor diet/dehydration going into your workout. You are already at a 5, leaving only 2 units available to come from workout stress – in other words it may well take less power/pace (input) to reach that same HR (stress indicator). And that’s OK – training under both conditions will give you the same benefit, but under the 2nd scenario, if you tried to push the same power/pace, (6 ‘stress units’) you would be overall at 11 – well over your LT1 limit and chronically doing this leads to hormonal issues, adrenal fatigue, over-training and the loss in threshold that we are seeing from the continual zwift racing.
So, come into TCR and get your LT1 zone established and chat with us about our programs and coaching designed to advance your fitness, keep you healthy for life and able to do the activities you love with friends.