Lose weight while running long

Last updated: 23-Aug-18

By Renee McGregor

For many years conquering the 26.2 miles of a marathon was the ultimate endurance challenge on the running scene. Fast forward to present day and the range of ultra-running distances you can choose from – 50k, 100K, 100miles, 24 hour races – is pretty endless. Once you’ve decided on your distance then comes the question around which terrain – road, trail, forest, mountains or my personal favourite, one race with sections of all of the above.

Those of you that have converted to the ultra-running distance, will know that there is quite a bit to think about; from the most appropriate kit – shoes, packs, bottles, shorts; to hydration and fuelling. Get the fuelling wrong in an ultra and it is easily game over.

Nutrition for ultra runners is about delivering enough energy to working muscles, enabling you to complete those tough sessions, which will allow for progression and improvement; it is also about recovery and developing strength.

But what if your motivation to increase your distance is related to an actual requirement to dropping a few pounds (that is, you have been medically told).

One of the most common mistakes I have seen is that runners cut back too drastically. Thus, instead of achieving the weight loss they hoped for it can actually have negative effects:

  • Leaves the individual feeling low in energy and unable to train.
  • Results in loss of both body fat and muscle mass. The higher the muscle mass within the body, the more metabolically active you are – i.e. the more calories you burn per minute even at rest. So when losing weight, you want to retain this muscle mass as much as possible and this is not achievable on fad diets.
  • Sets an individual up to fail. The human body will always aim to achieve energy balance even if it’s not the weight you want to be! Thus cutting back too drastically on energy intake, leaves the body feeling severely depleted, and more likely to fall off the wagon. It is just not sustainable for the body to work effectively or efficiently on a very low energy intake.

The key will be to look at your training week and then tailor your food choices against this. Contrary to popular belief this does not mean filling up on plates of carbs before every run.


Here are some top tips:

1) Be realistic about the energy burn.

Remember that those slow to moderate intensity runs, while hugely beneficial in increasing your overall energy expenditure, don’t give you the green light to go ahead and indulge in that huge piece of cake mid-afternoon.

Contrary to what you may think, a run of this level will have a fairly low energy yield. Similarly, you must not forget that if you were sat at your desk instead of running, you would still burn a percentage of those calories.

So, where your watch might say you have burnt 400Kcals for an hour’s run, remember that also includes the amount of calories your body would normally burn for this hour, regardless of activity.

Therefore, while the energy burn has been raised, it probably wont be as much as you expect. For those of you who’s primary goal is weight loss, you will negate the whole process If on every run day you then proceed to “treat” yourself. That said having the occasional piece of cake is also not going to sabotage your goal. Just be mindful about how often “occasional” is.

2) What’s the deal with recovery?

We’ve all been told about the 30-minute recovery window but how important is this in reality? This only becomes relevant if, either you are running at a high intensity and your next meal is over two hours after finishing; or you are someone who is planning a further run within 12 hours.

This means that for the majority of us who are only training once a day, our next meal is sufficient for recovery. This is often one of the main reasons I find individuals who are running to lose weight, don’t. They are eating additional “recovery” calories, which they do not need.

3) Periodising Carbohydrates.

In order to really benefit from your training plan, it is important that you plan ahead so you know what to eat when; indeed nutrient dense carbs such as oats, whole grains and sweet potato are very useful for fuelling up before high intensity sessions which would include hill repeats, intervals or long endurance runs over 90 minutes long. However, portions should be adjusted prior to slower more easy to moderate paced runs.

4) How Much?

Don’t just think about your nutrition in the meal or snack immediately before your run session. If this is going to be a high intensity session, you actually need to think about getting a regular intake of carbohydrates at all meals and snacks during the 24 hours prior to your session. This will ensure that you have sufficient glycogen stores to maintain a consistent pace throughout your session.

So for high intensity training, aim for around a fist size portion of carbohydrates at your meals and a further ½ fist portion of carbohydrates at 1-2 snacks prior to training. Good suggestions include 2 oatcakes with peanut butter; banana with 5 brazil nuts; or a small cereal bar.

For lower intensity training, aim for a fist size portion of carbohydrates at your meals but stick to protein based snacks –  1-2 a day as required. Good suggestions include 15g of beef jerky; 100g edamame beans or 100g cottage cheese with crudités.

5) Don’t ditch the dairy.

With so many food bloggers evangelising dairy-free milk alternatives such as almond, coconut and hemp, it is important to know that cow’s milk is actually one of the best recovery options you can choose post training.

Not only does cow’s milk have the right proportions of carbohydrate to protein to encourage muscle recovery, it also has the best composition with easily digestible carbohydrates and protein, making uptake by the muscle more efficient. In comparison, if you look at shop-bought almond milk as an example, it is just expensive water.

Dairy foods also contain calcium and this has been demonstrated to have beneficial effects on body composition, helping you to maintain a higher percentage of lean muscle mass.

6) Protein Power.

Many individuals see protein foods as the most important component of recovery. This is not strictly true and once again depends on the type of training you have completed. For those of you who are regularly doing high intensity running, such as intervals or tempo runs, then actually replenishing your body with carbohydrate after is equally as important as protein. This is where milk is such a great option as it is the prefect composition of carbohydrate, protein, fluid and electrolytes for recovery.

However for those of you who are trying to drop a few pounds through your running, then trying to consume protein regularly through the days at meals and snacks is a great way of maintaining lean muscle mass while you are restricting your energy intake. Additionally, protein helps to keep you full and so this can prevent the need to dip into the biscuit tin mid-afternoon.

Try including eggs at breakfast, chicken or hummus for lunch; snack on Greek yogurt and fruit mid afternoon, and fish or tofu for dinner.

7) Don’t forget about your Vitamins and Minerals.

We all know that fruits and vegetables are good for us. They provide us with essential vitamins, minerals, anti-oxidants and fibre. They are also low in energy and can help keep us full.

Root vegetables such as carrots, swedes, butternut squash are all great choices on low carbohydrate days as they help us to stop feeling deprived if we can’t serve out chicken breast with a great big jacket potato.

Herbs and spices are also very potent in anti-oxidants which are essential for numerous processes within the body, including preventing oxidative damage to the muscle – a perfect excuse to cook a vegetable curry full of vibrant colours and spices.

About the writer: Renee Mcgregor is a Sports Nutritionist and Author who has worked with Paralympics GB and many GB endurance athletes.

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Entry Fee
Entry Fee - slider


Date Range

Global - Virtual


A virtual race which can be run at any time shown on the dates shown, on any type of terrain in any country.

Suitable for

For runners from beginners to experienced as you choose your own course and challenge based on the guidelines and options set by the virtual race organiser.

Endurance - Multi-activity


An ultra distance race including at least two of the following activities such as running, swimming, cycling, kayaking, skiing and climbing. It may also include different climatic conditions (eg ice, snow, humidity, cold water, mud or heat).

Suitable for

Experienced multi-skilled athletes who have trained for the different activities included in this event. Admission to these races may be subject to receipt of a recent medical examination certificate. Check with the race organiser regarding entry requirements and any specialist equipment required such as a wetsuit, skis or a mountain bike.



Increase of up to 2000 metres with very challenging climatic conditions (e.g. ice, snow, humidity, heat or at high altitude)

Suitable for

Very experienced long distance ultra runners (min 3 years’ experience) or are doing regular long distance running (>50 miles) with elevation and conditions shown (where possible). Admission to these races is often subject to receipt of a recent medical examination certificate. Purchase of specialist kit is often recommended for these races.



Increase of up to 2000 metres with some challenging climatic conditions (e.g. ice, snow, humidity or heat)

Suitable for

Experienced runners who have completed at least 4 ultras in last 12 months, or are doing regular long distance running (>50 miles) with elevation and conditions shown (where possible). Admission to these races may be subject to receipt of a recent medical examination certificate. Check with the race organiser regarding entry requirements.



Increase of up to 1500 metres

Suitable for

Runners who have completed several ultra distances or similar events, or are doing long distance running regularly, with elevation shown.



Increase of up to 1000 metres

Suitable for

Runners who have completed at least one ultra in last 6 months or are doing long distance running (>26 miles) regularly, with elevation shown.



Very little change < 500 metres

Suitable for

First ultra event. Runners completing a marathon or doing regular long distance running (>26 miles) in the last 6 months.