Personal fuelling playbook
June went 1:43. The October half got scratched to protect a calf — the marathon matters more. The new anchor: the Toronto Marathon, May 2, 2027, chasing a Boston qualifier (3:25 standard for women 18–34, target 3:18–3:20). Runna handles the running. This handles the fuel, built around 59kg, gluten-free eating and endo-friendly recovery.
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Days to race
4:51
BQ pace / km
7:49
BQ pace / mile
65–75g
Race carbs / hr
80g protein and 150g carbs is roughly 1,500 kcal of macros against a training load that burns closer to 2,400. Five things to change, in order of impact.
You're at ~150g a day, which is 2.5g per kg. On 50km weeks plus lifting and daily yoga, a marathon build needs 4–8g per kg depending on the day — roughly 235g on the quietest day and up to 470g before a long run. Chronic low carb is the single most common reason a runner plateaus, gets injured, or loses their period.
80g is 1.35g/kg — fine for a desk job, low for a lifting runner. Target 1.8–2.0g/kg: 105–120g, split across 4 feeds of 25–30g. Best gluten-free, endo-friendly hits: eggs, salmon, sardines, chicken thigh, goat yoghurt, feta, lentils, tofu, whey or pea isolate.
Heavy or painful cycles with adenomyosis plus 50km a week is the classic recipe for low ferritin — and low ferritin feels exactly like bad fitness. Ferritin was 35 ng/mL; follow Dr. Ho’s iron and retesting plan rather than adjusting the dose yourself. Pair iron-rich foods with vitamin C and separate iron from coffee and tea.
Goat cheese and feta alone may not cover calcium needs. Add sardines with bones, tahini, fortified GF oat milk, calcium-set tofu and greens; discuss vitamin D supplementation with your clinician.
Oily fish, enough total energy and consistent sleep support training recovery. Talk through supplements and endo symptoms with your clinician rather than adding them from a checklist.
Carbs move with the session, protein stays high, fat stays steady at 55–70g. Pick the day you're on.
Threshold, intervals or race-pace work
355–415g
Carbohydrate
105–120g
Protein
2,450+
2,450 – 2,700 kcal
Fast sessions run on glycogen, full stop. Front-load carbs before, sip carbs during if the session is over 75 min, refuel inside 30 min.
Taking 65–75g of carbs an hour is a trainable skill. Build it across the block so race day is a repeat, not an experiment.
Weeks 1–3
30–40g carbs/hr
On longer runs after the calf is cleared, start with familiar SiS gels and note stomach comfort.
Weeks 4–6
45–50g carbs/hr
Add a tested carb drink, counting its carbs alongside gels.
Weeks 7–9
60g carbs/hr
Practise the planned drink and gel schedule on a long run.
Later build
65–75g carbs/hr
Rehearse the full race-day plan on long runs with marathon-pace segments; stop increasing if your gut objects.
Rehearse the full food and carry plan on spring long runs. These are training targets for 59kg, not a fixed prescription.
T–48h
470g carbs across the day. Low fibre, low fat, familiar gluten-free foods. White rice, potatoes, GF bread, jam, honey, bananas, sports drink. Salt your food generously.
T–24h
Another 470g carbs. Add an electrolyte drink with dinner. Expect +1kg on the scale — that's stored glycogen and water, not fat. Legs will feel heavy. Correct.
T–3h
White rice or GF bagel with honey and jam, banana, small coffee. Nothing new, nothing high fibre, nothing dairy-heavy. 500ml fluid with electrolytes.
T–15 min
One familiar SiS gel with water if this has worked in training. Count it separately from on-course fuel; account for any caffeine already in your coffee.
During
For a 3:20 race, that is about 215–250g on the course. Combine familiar gels with a tested drink and water from aid stations; a single 500ml flask cannot last the whole marathon. Match sodium and fluid to conditions and your tested needs.
Finish
Then a real meal. Salt and fluid for the rest of the day; you'll be more dehydrated than you feel.
White & jasmine rice, potatoes, sweet potato, GF oats, buckwheat, polenta, rice noodles, GF sourdough, bananas, honey, maple, dates, dried mango
Eggs, salmon, sardines, mackerel, chicken thigh, lean beef (iron), prawns, tofu, lentils, chickpeas, goat yoghurt, feta, whey or pea isolate
Beef, sardines, lentils, pumpkin seeds, spinach with lemon, oranges & kiwi for vitamin C, tart cherry juice after hard sessions
Gels you tolerate (test 2 brands), carb drink mix, salt tabs or LMNT-style electrolytes, rice cakes, GF pretzels for salty long runs
Personal training notes, not medical advice. With endometriosis and adenomyosis in the picture, run the iron panel and any supplement changes past your doctor or a sports dietitian.