Fuelling the fat-adapted athlete

On August 1st I’m releasing my athlete-specific meal plan, which is a long time coming given that I consult with many endurance athletes! It’s hard to be specific with a general plan, clearly, particularly when it comes to training nutrition, so when you sign up I encourage you to contact me to see if we need to tweak the elements of this plan to suit your training.

The goal of an athlete training plan is to provide fuel where required, be strategic about the type of fuel and when to have it. I want to help make you a more efficient athlete – so your training and recovery is optimised to enable you to get out there day in, day out in the best possible shape. This will allow you to show up to the start line (or game day) in the best position to do your best. Like recovery, nutrition is vital to enhancing fitness gains from your session – eating the wrong types of food increases oxidative stress and dampens down your immune system, leaving you susceptible to inflammation, illness and injury. If you don’t recover effectively from the previous training session, your ability to get out the next time and hit certain paces/power is compromised – therefore overall fitness gains aren’t realised and you may not reach your potential awesomeness. I’ve written about this previously in more detail here.

To be metabolically efficient, we want to be strategic about when and how we have our carbohydrate, how much we have and the quality of the carbohydrate source. That is why in the plans I focus on adding fruit, kumara or potato after training if the training requires additional carbohydrate to support recovery. By removing carbohydrate from the pre-training meal/snack, we don’t have an insulin response that will drive circulating glucose (what carbohydrate is broken into) in to your muscle cells, shutting down lipolysis (fat burning). The body will be forced to use alternative fuel sources such as fat which, as an endurance athlete, we should be primed to do. The reality is, though, the modern diet that a typical athlete follows has made sugar burning the default training state, even at low intensities. Even the leanest marathon runner has enough fat calories on board to go out and run back to back races – accessing this though is the problem! Fat as a fuel source creates a lot less oxidative damage and reactive oxidative species, thereby the inflammation you experience post-training is reduced, recovery is enhanced, and you’ll be able to hit the next session fighting fit. We need to adapt from a carb burner to a fat burner for you to go out and train and not risk bonking or running out of fuel. The switch over doesn’t happen overnight, and if you’re new to this approach then training can feel pretty sluggish to begin with – but hang in there as it does get easier!

There are different approaches to fuelling depending on your goal:


If body composition improvement is your goal, it is best to do fasted training sessions or use coffee/caffeine as an ergogenic aid and fuel afterwards. This doesn’t mean that you’ll lose MORE body fat than if you were just to reduce calories, but it will force your body to tap into its own reserves, which (when combined with this dietary approach) I’ve clinically seen helps accelerate fat loss in the context of this eating style. For extended, longer duration >3h+ then having some fuel (as suggested in plan) can be a good idea, or starting fasted and taking on board fuel after 45-90 minutes depending on session is optimal.

If you are happy with your body composition or do not want to drop any body fat, then you can choose to take on board some fat before training – such as cream in coffee, MCT oil powder in coffee, or ketones. By fueling before training, you will shut down your own fat oxidation, but be upregulating pathways for fat oxidation, however it will be burning the fat that you consumed. This option is also good for people who have higher cortisol levels – training in the absence of any fuel can further exacerbate the ‘stress’ response from your hypothalamus (brain). Taking on board some calories sends signals to your brain that there is no need to stress. Taking the ketone supplement has been found (compared to fasting) to upregulate fat oxidation at lower given intensities; once the intensity rises to a high intensity, the opposite may be true (potentially due to the ketones being used to spare glycogen at the higher intensities).

If you struggle to maintain your weight and need to work at keeping calories high, then adding in some additional protein alongside could also be a good option – this could be a couple of hardboiled eggs, some scrambled eggs, additional fat-based calories or a smoothie based on nuts, avocado, some protein powder, coconut milk, greens, with no fruit). Again, this will provide a minimal insulin response, meaning your body will be burning the fuel you provide it (fat calories) and therefore working towards improving metabolic efficiency.

In all instances above, 10g of branched chain amino acid powder can help fuel a longer session – just mix in water beforehand.

In a perfect world, the best type of training to do if you are new to this is low intensity training; this is because your body needs to relearn how to burn fat as its primary fuel source. The ultimate goal down the line is to become metabolically flexible (ie easily shift between both sugar burning and fat burning) – and that will happen! That means the natural switch over to burning sugar that occurs when training at higher intensities will not impact on your fat-burning capabilities at the lower intensities. Right now, though, if it’s all new to you, your default is to burn glucose at that high intensity. Any shift back into glucose burning at this stage will impact on your ability to burn fat and can leave you in no-mans land when it comes to training. What I mean is, you are following a lower carbohydrate approach to diet, so there is no glucose on board as a ready source of fuel, yet you are too high intensity for your body to use fat as a primary fuel source (at this stage). No mans land.

However, it rarely happens that an athlete is always training low intensity, even in their off season. Therefore supplementing with an exogenous ketone supplement (such as Pruvit) provides your body with fuel the way a carbohydrate gel provides glucose. Ketones are the byproduct of fat metabolism, and when you burn fat as a fuel source, your body generates these to support metabolism. At a high intensity if you’re new to this, taking exogenous ketones provide you the fuel to enhance fat oxidation before your body has the machinery in place to do it for you. Otherwise the intensity will force your body to switch back to glucose burning. Remember, in the initial phases of your fat-fuelled approach, your body has to upregulate the machinery required for fat adaptation – it isn’t the default fuelling response. Any opportunity to switch back to burning sugar, it will take it.

Taking the ketones (along with MCT oil powder) will provide the fuel you need for the training without the need to use glucose, and is recommended in this instance. Further, ketones aid in recovery from longer sessions, and most athletes I work with who use them experience reduced inflammation, less excessive hunger, and can go for longer at a higher given intensity without an increase in their heart rate or perceived effort. Most have also experienced improved body composition due to these reasons. My recommendation is to have ½ sachet of the ketones and you can include 10g of MCT oil powder with it prior to your session.

During training:

 Shorter training up to 2h, low-mod intensity

Nothing – perhaps water, or an electrolyte fluid (no carbohydrates required*)

 Medium length from 2-3h low-mod intensity

Evaluate how you feel, take some MCT mix (see below), Superstarch (30g/hour in 750 ml bottle), ketones as below (sachet in 750ml bottle, 1/3 bottle hour), otherwise just electrolyte fluid.

Longer training: over 3h

36g MCT oil powder + 20g BCAA + ¼ tsp salt in 750 ml bottle OR sachet ketones, 18g MCT oil powder + 20g BCAA in 750ml bottle – ¼ bottle per hour AND every 45 minutes have something small, solid, food based: ¼ – ½ Cliff bar, 30g cheese, hardboiled egg, small handful cashews, ½ UCAN superstarch bar, homemade bar (such as apple pie blondie).

If including high intensity intervals

Try carb rinsing: 5-10 minutes before starting effort, have a glucose tablet, thereby trickling in carbohydrate – this method tells your brain you’ve had carbohydrate onboard without taking anything on. OR have sachet ketones in drink bottle as above.

*may need something if getting into it for first time, and suggestion is the ketone supplement here to help aid the fat oxidation pathways.


If body composition improvements are a goal, train around your meals so you don’t need to eat in addition to them, also can create a ‘train low’ environment by withholding food for around 45-75 minutes to further enhance fat oxidation. If higher intensity effort, include 10g BCAA powder in water post-training to preserve muscle mass.

If happy with body composition, then you can do as above or add in a protein shake with around 25g protein, use unsweetened almond milk to help provide calories and preserve muscle mass. Having the other ½ of your ketone sachet here can enhance recovery. Include 10g BCAA in water post-training to preserve muscle mass.

If you struggle to maintain your weight (or you are training hard again in next 8 hour period), then adding in the protein shake as above, plus serve of good quality carbohydrate such as kumara, potato, a piece of fruit can provide calories plus easily digested fuel to support recovery. Including the other half of your ketone sachet here can enhance recovery and include 10g BCAA in water post-training to preserve muscle mass.

In all instances, if the training is long, then I think the benefits of post-workout fuel outweigh ‘train low’, especially if you have a heavy or longer session the next day as a lot of ultra runners or triathletes do.

This isn’t definitive, and someone else will have a different approach, however these are generally the guidelines I have used that work with clients and that may work with you.

Remember, though, the best way to get fat-adapted is to adopt a daily diet that supports fat metabolism – click here to sign up to my plans and use the above guidelines to support your training.


The fuel I used pre-half marathon at the beginning of my marathon training program: 1/2 ketone sachet, MCT oil powder, coffee and PB.

Injury-prone? Read this.

Nothing derails an athlete like an injury. We all know that consistency is one of the most important aspects to perform at your best, but getting to the start line in one piece is one of the biggest challenges that athletes face – particularly endurance athletes. For me, I have a long standing battle with my calves, and many people I talk to are similar: an old achillies injury, a hamstring problem, a niggly hip. However, this is hope! I listened to this great podcast where one of the leading researchers (Keith Baar) talked about his research that is helping athletes avoid injury and (when injured) recover more quickly. It is so practical and easy to apply that I had to share it. And whilst this is related specifically to athletes, I can’t think of any reason this couldn’t apply to anyone who may not think of themselves as an ‘athlete’ but struggles with an ongoing muscle or bone ailment.

A bit of background: Collagen, the most abundant protein form in the body, is made up of two amino acids, glycine and proline. It is found in bones, muscles, tendons and ligaments and has an almost scaffolding effect, to provide form and structure. Modern diets don’t contain a lot of glycine – it is found in the cartilage, bones and gelatinous part of animals and most people prefer the leaner cuts of meat (such as a steak, or a chicken breast). Most athletes I talk to would fall into this category; traditional sports nutrition guidelines would encourage them to fill up on carbohydrate, eat a moderate amount of lean protein and choose those leaner cuts of meat to ensure fat intake is kept low. Another easy source of glycine is found in gelatine – the wide, grainy powder found in the baking aisle used as a gelling agent in cooking. It is made predominantly of left over parts of the animal (bone, skin etc) that would otherwise not be used and has become more popular recently for its health promoting properties. Gelatine has also garnered the attention of sport scientists for its potential role in healing from injury and injury prevention.

While mere mortals wouldn’t typically think of tendon stiffness as a good thing, sport scientists have shown that the higher degree of stiffness you have in your muscle tendons, the better efficiency you’re going to have when using them. For a runner this would mean you’d expend less energy overall at a higher given intensity. And who doesn’t want that?

Tendon stiffness is determined largely by the amount of collagen AND the crosslinking of it. the collagen (tissue). Cross linking is determined by enzymatic processes that occur in the body, the expression and the activity of these enzymes increases when we are active. Baar’s research found that when they combined vitamin C (important for collagen synthesis) with glycine (one of the most common amino acids in collagen) there was an increase in strength of ligaments the engineered in the laboratory. They then conducted clinical trials in athletes to determine if this could be translated to a real world situation.

They conducted a randomised clinical trial, whereby they gave the group either a placebo, 5g or 15g of gelatine and measured the amino acids present in the blood stream over the following three hours. They found that the glycine peaked within the blood an hour after consuming the supplement. When they took the blood samples from the athletes and put it into their engineered ligament, they found an increase in the amount of collagen present in the ligament – a slight increase with 5g and a substantial increase with 15g of gelatine. Importantly, they found improved strength and stiffness in the ligaments that had the increase in collagen formation.

They then had the athletes jump-rope for six minutes (the length of time required to get a response from tissue cells in the bones, tendons and cartilage), rest for six hours, take the supplement again, wait an hour (for the peak amino acid expression) and jump-rope again. They did this three times a day for three days. The researchers found a doubling in the athletes’ collagen synthesis for those supplementing with 15g of gelatine, mostly from the bone.

What this shows us is if we want to improve the collagen response to an exercise bout, we can easily do this by adding gelatine as a supplement. Baar felt the initial study can be looked at as a bone recovery protocol. If we have an athlete who breaks a bone –  in the foot, a bone in the leg, bone in the back, what you can do is you can have them take the 15g gelatine alongside 50mg of vitamin C and then do five minutes of exercise an hour later. Now clearly this isn’t weighted activity – if you have access to an AlterG at your local university sports science lab that would be brilliant – something that is going to just direct those nutrients to where they need to go. Repeat this every 6h because it takes that long to get the cells to return to a state that they will then be responsive. The researchers suggest this is going to speed recovery time, something all athletes are interested in.

The above study can also be used as an injury prevention protocol, as the overall goal is to improve the mechanics of the connective tissue, reduce fatigue-related damage and optimise its strength and resilience. The protocol is the same; consume the 15g gelatine and 50mg of vitamin C then perform 5 min of activity that is going to load the area they are most concerned with. Long distance runners, for example, could supplement and then an hour later do 5-6 minutes of jump roping as this is going to load the hips, Achilles tendon, calves, tibia and femur – all areas of concern. For our long distance runners, they do five to six minutes of jump rope because if you have a history of tibial stress fractures or hip stress fractures or Achilles problems or plantar fasciitis, all of those structures are going to be loaded by the jump rope. They’re going to get just enough of a stimulus in that six minutes to have a response. Unlike muscle, bones and connective tissue don’t have a great blood supply – therefore providing nutrients then doing the exercise is like wringing out a sponge – suck the water out and it will suck up what’s left in the environment. The exercise impact is like wringing out the sponge, therefore the tissue will be responsive to up taking the nutrients.

Currently they’ve just tested the 5g and the 15g of gelatine – and while anecdotally the 5g has received favourable responses, the 15g amount was significantly more effective. The researchers don’t know for now if this is better scaled to body weight, but studies are underway to determine this. The study that is discussed here is in review and is about to be published.

In summary:

Bone healing / injury prevention protocol

  1. 15g gelatine + 50 mg vitamin C* (either added to smoothies, glass of water etc)
  2. Wait an hour for peak amino acid presentation in the bloodstream
  3. Undertake 5-6 minutes of activity that loads the area of interest (can be non-weighted) to direct nutrients to that area. For an ankle injury, this can be simply (carefully) tracing the alphabet with your ankle
  4. Do this every 6h
  5. (for injury prevention) – can do this anytime – or take the gelatine + vitamin C an hour before training if the training is including drills/warm up that targets area of interest.

*a little bit less than the amount of vitamin C found in a kiwifruit, most vitamin C tablets are over 250 mg, but you could easily have this instead.

Gelatine: I use the Great Lakes Gelatin, this is definitely pricier than what you’d find in the supermarket. This (and the I Quit Sugar brand or Vital Proteins brand) are marketed as being derived from either pig or beef that have been sustainably farmed and pasture raised. They are also free from additives and preservatives. You can purchase either the gelatine that will gel, or the collagen peptides which is the collagen broken down into smaller amino acid peptides. I haven’t seen any New Zealand gelatine – our cattle industry is one of the best. The brand in the supermarket I’ve seen (Mckenzie’s) includes a preservative which wouldn’t make it ideal for anyone wanting to use it for gut healing purposes (it’s 220, sulphite dioxide – many people are sensitive to this) and they don’t make the same animal and environmentally friendly claims. Further, if you do have an injury then the levels of inflammation in your tissues will likely be higher, and while the inflammation may not stem from your gut, it can affect your sensitivity to constituents in food such as preservatives and additives you would otherwise be fine with. In terms of the injury prevention effect though, I’ve seen nothing to suggest they wouldn’t be on par – so choose the one you can afford.