Matt White, a former Pro Triathlete who was second at IMWA in 8h18 is a strong believer in ES (empty stomach) training & so am I.
I was always impressed by how lean and muscular he was. I have done ES training my entire life and lately 5 days per week. It helps me lose weight and feel good when I train because I don’t have food sitting in my guts, and it puts me in a spot where I don’t have that many carbs store left so I burn fat quicker. To be honest, if I eat before training, the blood stream goes into my stomach for digestion and I just want to go back to bed to sleep.

I am talking even just a piece of toast will make me feel sleepy and not want to train. I don’t eat before a race either, unless it is an Ironman. Then I will have a couple of slices of toast with honey to boost my carbohydrate storage at the last minute before racing. I always have caffeine 30 minutes before ES training to boost metabolic rate and fat burning. It can be a coffee, black tea, green tea or a caffeine pill.



When you eat a meal containing carbohydrates, your body releases insulin, the hormone that helps regulate blood sugar levels. Without it, our blood sugar would spike after meals, remain elevated and we would eventually die because too much sugar in our blood is toxic. On the contrary, insulin is also a fat storage hormone. So when insulin is elevated (as is the case after you eat) your body will be in a state of wanting to store fat, not burn it. It doesn’t matter if you exercise like a mad man after a meal, you won’t be able to burn body fat until insulin levels drop, which can typically take two to three hours, if not longer.



Growth hormone is another hormone that controls fat burn.
Growth hormone not only facilitates fat burn, but also stimulates muscle growth and metabolism. And incidentally, insulin and growth hormone are competitive hormones. When one hormone is elevated, it will suppress the other hormone. So when we eat something, insulin levels rise, suppressing growth hormone. On the flip side, when we’re in a fasted state, insulin levels are at their lowest point, so growth hormone will be elevated. Knowing this about how hormones work, and knowing more about your own fitness level and how your body responds to exercising on an empty stomach is important.



There are also potential benefits for endurance athletes, as fasted workouts can improve muscle glycogen storage efficiency. What this means is that the body learns to make better use of its energy stores. The occasional fasted training session can help improve your performance during regular fed training. When the body learns to exert itself without any food, it gets better at exercising when it does have fuel in the tank. Studies suggest that fasted training can increase your VO2 max, which is the maximal amount of oxygen our lungs can uptake at any given time, the better this is, typically, the higher the level of fitness. ES training will also teach your body not to be lazy and to not always rely on outside energy as it will have to dig into its own reserves to find energy.

The natural order of your body using its resources will be carbs, fat, protein and muscles.



Mental strength is also something you practise during ES work outs. You might be getting out of bed feeling flat and tired. You just want to eat and get a kick from a good meal but you need to go out and run for an hour. You feel in sync with your body, you will feel everything so much more than if you had a fuelled gut. You are more in touch with bodily sensations, emotions and soreness. It will be a mental battle to get going some days if you feel low on energy but you just need to keep pushing & battle forward. You need to resist the kick from absorbing calories, the rush of endorphins, the feel good sensations from eating and the release of flavours on your palate. That takes mental strength too! I love food 🙂



I get out of bed some mornings, feeling empty, sore, low on energy, not waiting to hurt myself, not wanting to keep going. I just want to lay down and rest. I want to pull the pin but giving up is not an option…

Does that remind you of something? It does to me as this is the way I feel for the last 21kms of every Ironman I have done. I am so exhausted physically and mentally in the last part of the marathon that I sometimes just want to lay down on the side of the road and sleep, or I want to stop at an aid station for a smorgasbord. So ES training will put you in a similar mental and physical state as that last 21kms on the run. Practice this so that you get a feel for it. This is a chance we have that should not be missed. To be successful at racing, you need to duplicate racing conditions as much as possible. Ironman has aid stations, but so do you when you train. Just bring some gels with you and if you feel terrible, then only do 30min of ES training. ES training is also very good for marathon training.



In my experience, it has to be done step by step. It is not easy to get used to and it can be taxing both physically and mentally. You need to have a good level of fitness before you try this.

Like being able to swim 1500m, ride an hour or run 5kms non stop then you can start. Start with 20min of ES training twice a week and increase by 5min each week. When you get to 1h then you can increase to 3 times per week. Please do not go above 2h of ES training as low energy levels have shown cases of increased tendinopathy, eating disorder, bone density issues, loss of concentration, protein breakdown and loss of muscle mass. Bonking (running out of energy) can be dangerous if you’re out of it and in the middle of nowhere. Always carry food on you!

ES training is recommended for cardio workouts and not for gym work for example as this can involve muscle mass loss. Muscle break down is a good thing, but not muscle loss, especially for gym work.

ES training can be dangerous so please do it step by step and always have a few gels on you to take if you need it. No point staying on ES for 2h if you need to walk for half of it. You need to prioritise the quality of the work out above ES training or weight loss.
Weight loss should be mainly done via a good, healthy and balanced nutrition.

I will only go up to 2h of ES when I feel at my lightest and fittest but most of the time I don’t go over 90min. Right now, I am up to an hour ES training. My rule of thumb is:

30min of ES training if I feel rubbish

45min of ES training if I feel OK

60min of ES training if I feel good

75min of ES training if I feel super good

90min of ES training if I am on top of the world

and above that if I feel at my best and fittest.


For the swim, I only use liquid energy like 32GI Low GI drink for example

For the bike, it will be a mix of liquid energy, 32GI gels and 32GI Chews

For the run, it will only be using gels

Please be careful trying this and make sure you eat a complete meal that has carbs, protein and fats within an half to an hour after you have finished the ES work out. Your body and muscles will act like a sponge and absorb all nutrients much quicker which will help recovery.

Do not hesitate to send me an email if you have any questions. I am not a qualified nutritionist, I only speak and share things from my own research and my own experience having been in the sport of triathlon for 35 years now. Contact me on and train safe 🙂