Leading a low carb lifestyle and endurance training is tricky.. Here is a list of books and websites by very well respected people who pioneer low carbohydrate diets and endurance training.
I’m a Triathlete – wanna be Ironman. Taking into consideration my height, weight and activity levels I need to consume anywhere in the region of between 4500 kcal and 5500 kcal a day – sometimes more when I’m killing myself at weekends.
This is a lot of calories to take in - even tougher when low carbing as you can imagine. The best way to meet these extra needs are through constant snacking (every 2.5-3hours) and protein shakes.
Adding peanut butter to shakes is a good way to get the extra calories in without too much carbs. There is a peanut butter on the low carb megastore Josephs Creamy Valencia Peanut Butter (per 32g serving; 200kcal, 6g carbs, 9g protein and 15g fat.) Alternatively there is good old sun pat which is actually lower in carbs (per 50g serving; 315kcal, 6g carbs, 13g protein, 26g fat.)
I'm afriad it's going to be a lot of trial and error - what works for me, may not work for you.
Here is some advice given to me by a low-carb endurance athelete:
When training really hard, your carbohydrate intake will need to increase so I would advise adding extra vegetables to your meals, and in place of complex carbs (grains etc) it is more advisable to look to tubers and fruits.
On a low carb diet with low intensity training the body can make in the region of 200 grams of glycogen each day from fats and protein (and then we figure another 100 or so from your vegetables and fruits). That gives you enough glycogen to fuel your brain, get through an average day and to be able to do a short hard workout – and then do it again the next day. However, when you train long every day (over an hour), your carb needs will increase. The key is discovering EXACTLY how many additional carb grams you need each day to refuel muscles, but also to keep insulin and fat storage to a minimum. Too few and you won’t recover from day-to-day. Too many and you’ll set yourself up for inflammation and unnecessary weight-gain.
A simple medium banana provides 20g carbs when eaten about an hour to 30 minutes before training it should provide enough energy to get you through a workout of up to an hour.
This will have to be trial and error on your part because you will have to find the balance that is right for your body.
Even the most committed low carb endurance athletes still take gels and drinks when endurance is over an hour.
Right after a long training session or race, you’re in a critical period for glycogen refuelling. That first hour offers the most efficient opportunity for glycogen storage, and it’s fine to refuel initially with simpler (faster uptake) sugars. Take it slow and go for drinks first, then try some fruits and or yogurt with small amount of honey to get both carbs and protein in that initial window.
As you move past that first hour after training, tubers and more complex carb sources are good to include. Avoid grain-products as much as possible when increasing carbs. Depending on the length and intensity of your workouts (and races) you’ll need anywhere between 60-100 extra grams of carbs each day per hour of intense endurance work. It’s well worth the trial and error efforts to gauge your personal needs.
When endurance training is long it has been found that drinking 10-20 grams of sugars every 15 minutes after the first 60-90 minutes helps keep glucose in the bloodstream and thereby spares muscle glycogen. Any more than that and you run the risk of stomach upset. Once again, sports drinks are probably the most efficient source for carb energy, electrolytes and hydration. Though a piece of fruit might work for borderline training days, eating solid foods during a races generally backfires.
Because of the amount of training and intensity of training you are doing the amount of free radical damage going on in your body will be tens or hundreds of times greater than normal. When training so hard vitamin and mineral supplementation is essential. Your critical nutrient stores need refuelling, high levels of anti-oxidants are needed to repair the damage training causes.
I would recommend a decent all in one multi mineral and multi vitamin if you are not already taking one from any reputable store (Holland and Barrett or Boots) and I would take at least two daily. Antioxidants are critical for recovery and repair, B- vitamins critical for releasing the energy we need from foods, Iron – for the transport of oxygen and vital nutrients, the list goes on.
In some cases the rules need to be bent, especially in yours due to your increased needs. If you do not increase your carbs your body will give in and you will not be able to recover or train at the rate you need to.
I have included some carb contents below of fruits and vegetables to help you judge what your intake is and to help you with increasing your carbs.
Vegetables
Green Beans 3.2g per 100g
Mange-tout 4.2g per 100g
Aubergine (Fried) 2.8g per 100g
Broccoli 1.1g per 100g
Beetroot 5.6g per 100g
Asparagus 2g per 100g
Brussels Sprouts 3.5g per 100g
Carrots (raw) 7.9g per 100g
Cauliflower 2.1g per 100g
Cabbage 2.2g per 100g
Courgette (fried) 2.6g per 100g
Lettuce (iceberg) 1.9 per 100g
Mushrooms (fried) 0.4g per 100g
Onions (raw) 7.9g per 100g
Onions (fried) 14.1g per 100g
Parsnip 12.5g per 100g
Red Pepper (raw) 6.4g per 100g
Spinach (raw) 1.6g per 100g
Sweet Potato 21.3g per 100g
Tomatoes (raw) 3.1g per 100g
Tomatoes (fried) 5g per 100g
Fruit
Apple 8.9g per 100g
Apricot 7.2g per 100g
Apricot (semi dried) 36.5g per 100g
Banana 23g per 100g
Blackberries 5.1g per 100g
Cherries (raw) 11.5g per 100g
Dates (dried) 68g per 100g
Kiwi 10g per 100g
Peach 7.7g per 100g
Orange 8.5g per 100g
Pear 10g per 100g
Plum 8.2g per 100g
Prunes 34g per 100g
Raisins 69.3g per 100g