• Alice Clarke

Training Low for Endurance Athletes

When the concept of ‘training low’ was first flirted in the performance nutrition world, those championing it flipped the conventional stand-point around carbohydrate feeding on its head and raised a few eyebrows in the process. Challenging the long-held, proven principle of starting exercise with fully-loaded glycogen stores with a new twist has initiated more than a few questions along the way; hopefully this post can go some way to answering a few of these questions.


The concept behind ‘training low’ is that when an individual begins a training session with low muscle glycogen a number of subsequent adaptions take place in muscle cells. The key beneficial adaption believed to occur is an increase in the number of mitochondria present; an adaption that over time has shown to increase endurance performance and capacity. In addition to this physiological adaption, ‘training low’ also pushes your body to use stored fat as fuel in place of carbohydrates. Over time this may prove beneficial for body composition and has the potential to increase the intensity at which individuals can exercise whilst still using fat as the predominant fuel source.

If you are looking to embark on a ‘train low’ protocol it is important to ensure the implementation of this into your training is carefully planned. Incorrect execution, such as completing all sessions in a ‘low’ state, can adversely affect the benefits that you are looking to gain from this protocol. Essentially, there comes a point that you can’t achieve the benefits of this training style if you are too depleted to complete it properly. Below are some practical tips to ensure your implantation of a ‘train low’ protocol is effective as possible.


Know when to train low or high: training in a low carbohydrate state is not suitable ahead of undertaking high-intensity workouts and/or competitions. Plan ‘train low’ sessions for lower-intensity, longer sessions.


Don’t shift your entire mindset to low carb: when introducing the ‘train low’ concept, it is easy to get stuck in the low carb mindset. Whilst some training sessions may occur in a low carb state, re-fuelling post-training is still important!


Less is more: the benefits of ‘training low’ come from little and often – over-training in a low carb state can cause your ability to train/compete at a high intensity to suffer and in the long term can cause more significant effects such as a loss of muscle mass and a decline in immune function.


There are two common methods used to achieve the ‘train low’ status. The first, and arguably easiest method is to work out first thing in the morning after an overnight fast and avoid consuming carbohydrates during training. The second requires two training session in the course of one day. The first session will be completed in a high state to deplete muscle glycogen and, if no carbohydrates are consumed between sessions, the second session will be completed in a low state. Research has indicated that these methods may lead to different training adaptions therefore incorporation of both may provide more significant benefits.


Finally, how can you practically implement the ‘training low’ protocol into your current training regime?


1. Early in your training cycle introduce ‘training low’ periodically (1-2 times per week) to help maximise the aerobic adaptions. It is important to begin with a short, 30-minute fasted workout and extend your ‘low’ sessions to around 90 minutes. Recovery is important in the early stages so ensure 48 hours between your fasted sessions.

2. During the middle portion of your training cycle, as workout intensity increases and duration decreases ensure high-intensity speed work sessions are fuelled adequately, whilst endurance-focussed sessions are periodically carried out in a ‘low’ state.

3. In the consolidation phase of your training cycle where sessions are geared towards longer-duration speed workouts ensure that you are training in a carbohydrate-fuelled state.


The take home message from this is that if you are looking to incorporate ‘training low’ into your workouts, do it wisely and ideally under the supervision of a qualified individual. The best sessions to undertake ‘low’ are lower-intensity workouts, but make sure this is done periodically. It is important to note that during competitions and recovery periods adequate carbohydrate intake is needed to load glycogen stores and maximise performance.


If you would like more bespoke guidance on incorporating ‘training low’ into your training programme, please do get in touch with the ARC Nutrition team using our Contact Us form.

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