Protein Requirements During Recovery

Why Recovery Increases Requirements

The general population protein recommendation sits at 0.8g per kilogram of bodyweight — enough to prevent deficiency in sedentary adults. For anyone recovering from a significant musculoskeletal injury, this is substantially inadequate.

Achilles recovery creates two simultaneous protein demands. First, the tendon itself requires amino acid substrates — particularly glycine, proline, and hydroxyproline — for collagen synthesis and remodelling. Second, the calf and soleus muscles undergo rapid atrophy during immobilisation: research shows measurable muscle loss within 72 hours of immobilisation, and the gastrocnemius and soleus are particularly vulnerable because they are large, heavily loaded muscles rendered inactive by the boot.

Higher protein intake directly addresses both demands. It provides the raw material for collagen synthesis while also stimulating muscle protein synthesis and blunting the catabolic response to disuse. The International Society of Sports Nutrition (ISSN) position stand on protein and exercise supports 1.4–2.0g/kg for active individuals, with emerging evidence suggesting the higher end — and beyond — is warranted during injury recovery periods.

The Numbers

Translate the target range into practical daily amounts based on bodyweight:

Best Sources

Not all protein sources are equal for tendon and muscle recovery. The key variables are amino acid completeness (whether all essential amino acids are present), leucine content (the primary trigger for muscle protein synthesis), and — specifically for tendon healing — whether the source provides collagen precursor amino acids.

Source	Protein per 100g	Amino acid profile	Notes
Chicken breast Complete	~31g	Excellent — high leucine	Lean, versatile, easily portioned. Skin-on versions add collagen.
Eggs Complete	~13g whole	Excellent — reference protein	Highly bioavailable. Yolk contains additional micronutrients relevant to healing.
Greek yoghurt Complete	~10g	Good — high in casein	Slow-digesting casein is ideal before sleep to support overnight repair.
Salmon / fatty fish Complete	~25g	Excellent — plus omega-3s	Dual benefit: protein and anti-inflammatory omega-3 fatty acids.
Beef (lean cuts) Complete	~26g	Excellent — high leucine	Slow-cooked cuts (shin, oxtail) also provide collagen/gelatin.
Whey protein Complete	~80g (powder)	Excellent — fastest absorbed	Useful for hitting targets when appetite is reduced. Not a substitute for whole food.
Lentils / legumes Incomplete alone	~9g cooked	Moderate — low in methionine	Combine with grains or dairy to complete the profile. High fibre — good for gut health during reduced activity.
Tofu / tempeh Incomplete alone	~8–19g	Moderate — low leucine	Higher quantities needed to trigger leucine threshold. Tempeh has better amino acid profile than tofu.

Timing Matters

The timing of protein intake around rehabilitation sessions significantly influences how effectively it is used for muscle and tendon repair. The anabolic window is wider than was once believed — but timing still matters, particularly in an injury context where the anabolic stimulus is limited.

Before rehabilitation — consuming protein 1–2 hours before a rehabilitation session provides circulating amino acids during and after the session. This is particularly relevant for the calf raises, isometric work, and progressively loaded exercises that form the backbone of Achilles rehabilitation.

After rehabilitation — post-exercise protein within 2 hours is well-supported for muscle protein synthesis. A meal of 30–40g after each rehab session is more important than a supplement shake, but either works.

Before sleep — casein protein (from Greek yoghurt, cottage cheese, or a casein protein supplement) consumed 30–60 minutes before sleep has strong evidence for supporting overnight muscle protein synthesis. During injury recovery, overnight repair is a meaningful opportunity not to waste.

During Immobilisation

The immobilisation phase — roughly the first 6–8 weeks in a boot — is when protein intake is most critical and most commonly neglected. Activity is low, appetite may be suppressed, and the temptation is to eat less because you are moving less. This is the wrong instinct.

Muscle atrophy during immobilisation is driven not primarily by reduced activity but by the anabolic resistance that develops in immobilised limbs — the muscle becomes less responsive to the protein it receives. The compensatory strategy is to maintain or increase protein intake, prioritise leucine-rich sources, and distribute intake across 4–5 meals rather than 2–3.

HMB (beta-hydroxy beta-methylbutyrate) — a metabolite of leucine — has specific evidence for blunting disuse atrophy during immobilisation. Doses of 3g per day during the boot phase are supported by multiple trials. It is not a substitute for adequate protein but works as an adjunct to maximise the anabolic response from whatever protein is consumed.

Plant-Based Considerations

A well-planned plant-based diet can meet protein requirements during Achilles recovery — but it requires more deliberate planning than an omnivorous diet. The key challenges are leucine content (most plant proteins are lower in leucine than animal proteins) and amino acid completeness (most plant proteins are incomplete, lacking one or more essential amino acids).

The practical solutions: combine complementary proteins within meals (legumes with grains, for example), prioritise higher-leucine plant sources (edamame, tempeh, pea protein), and target the upper end of the protein range (2.0–2.2g/kg) to compensate for the lower bioavailability of plant proteins. Soy protein is the most complete plant protein and has the strongest evidence base — tofu, tempeh, and edamame are reliable foundations.

A Practical Day

For a 80kg person targeting 140–160g protein per day, a practical daily structure might look like:

Breakfast — 4 scrambled eggs with smoked salmon (~40g protein). Coffee.

Pre-rehab — 15g collagen with vitamin C, 60 minutes before the session (this is not counted toward the daily protein target — collagen is not a substitute for complete protein).

Lunch — 200g chicken breast with vegetables (~62g protein).

Afternoon — Greek yoghurt with mixed berries (~10–15g protein).

Dinner — 200g salmon with greens (~50g protein).

Before bed — cottage cheese or casein shake (~25–30g protein).

Total: approximately 185–200g protein — comfortably in the target range for a person of this size during the active recovery phase.