Tendons and stress fractures — the nutrition side of injury recovery
Nutrition is both cause and cure for the most common runner injuries. Here is what to eat during recovery — and what not to cut.
Stress fractures. Nutrition is both cause and cure. Causes: low energy availability, low calcium, low vitamin D, low vitamin K, amenorrhoea-associated bone loss. The single most important rule during stress-fracture healing: do not diet. Energy restriction impairs bone remodelling — the precise process you need to recover. Continue to fuel as if still training.
Bone-healing nutrition protocol:
- Calcium 1,500 mg/day during active healing (Lappe et al.)
- Vitamin D sufficiency (serum 25(OH)D >30 ng/mL)
- Vitamin K2 (MK-7) 90–180 µg/day
- Adequate protein: 1.6–2.0 g/kg/day, do not reduce despite reduced training
- Magnesium 300–400 mg/day
- Boron 1–3 mg/day (via nuts, legumes, fruit)
Tendinopathy. Shaw et al. 2017 — 15 g hydrolysed collagen or gelatin with 50 mg vitamin C, 1 hour before loading exercise, doubles collagen synthesis markers and supports connective-tissue recovery. Keith Baar's UC Davis lab has extended this to tendon-specific loading protocols (eccentric, heavy slow resistance) done 60 min after the collagen + C dose. The window effect is real: collagen synthesis peaks 4–8 hours after the pre-load, and loading during that window drives tendon remodelling.
Additional tendon supports: polyphenols (blueberries, curcumin), omega-3 (2–4 g EPA+DHA daily), protein adequacy. Corticosteroid injections are no longer recommended for most running tendinopathies — they weaken the tendon architecture over time.
Plantar fasciitis. No specific nutritional intervention has strong standalone evidence. Emphasise anti-inflammatory patterns, vitamin C for connective-tissue synthesis, adequate protein, and address any body-composition contributions that mechanically load the fascia. Most of the cure is mechanical (calf loading, plantar fascia stretching, footwear, gait) — nutrition is supporting cast.
During any injury (reduced training volume):
- Maintain protein intake. Disuse atrophy actually increases protein needs per kg.
- Reduce carbohydrate proportionally to training reduction, not absolutely. Still eat carbs.
- Emphasise anti-inflammatory whole foods.
- Do not crash-diet out of guilt. This is the most common psychological trap. Guilt is not hunger. Eating adequately during injury accelerates return to running.
Post-surgery. Vitamin C, zinc, adequate protein (1.6–2.0 g/kg), arginine for wound healing, collagen peptides for connective-tissue synthesis. Discuss any supplementation with your surgeon.
RED-S warning. If an injured runner starts restricting calories "because I'm not running", the injury becomes the door to a new and worse problem. Energy availability must remain at or above 45 kcal/kg FFM/day during recovery. If that target is uncomfortable psychologically, that is itself a reason to engage a sports registered dietitian.