At 50 years old and 73 kg, your nutritional needs are driven much more by your training load than by age. With 10 weeks until an Ironman, adequate carbohydrate intake is critical because many athletes under-fuel and limit training quality.

Protein

Endurance athletes generally benefit from:

  • 1.6–2.0 g/kg/day

For 73 kg:

  • Minimum: ~120 g/day
  • Optimal: 130–150 g/day
  • Upper: ~160 g/day

Spread across 4–5 meals, aiming for 25–35 g per meal. Post-training: 30–40 g within 1 hour supports recovery.

Carbohydrates

Training Day Target (g/kg) For 73 kg
Easy/rest 3–5 220–365 g
Moderate (1–2h) 5–7 365–510 g
Hard (2–4h) 7–10 510–730 g
Very long (5–7h) 8–12 580–875 g

Typical Ironman build intake:
Hard days: 450–600 g
Recovery days: 250–350 g

Fat

Recommended intake:

  • 0.8–1.2 g/kg/day
  • ~60–90 g/day

Supports hormones and overall energy needs.

Example Hard Training Day (~4,000 kcal)

Breakfast

  • Porridge with banana and honey
  • Two slices of toast
  • Greek yogurt

~130 g carbs, 30 g protein

During Bike Session

90 g carbs/hour for 3 hours

~270 g carbs

Post-Workout

  • Recovery shake
  • Bagel with jam

~80 g carbs, 35 g protein

Lunch

  • Chicken breast
  • Rice
  • Vegetables

~90 g carbs, 40 g protein

Dinner

  • Salmon
  • Potatoes
  • Vegetables

~70 g carbs, 35 g protein

Evening Snack

  • Cottage cheese and fruit

~25 g carbs, 25 g protein

Daily Totals

  • Carbohydrate: ~650–700 g
  • Protein: ~150 g
  • Fat: ~70–80 g

Fuel During Training

  • Bike: 75–100 g carbs/hour (up to 90 g/h common)
  • Run: 50–75 g carbs/hour
  • Protein: Not usually required during exercise
  • Post-session: 1–1.2 g/kg carbs (75–90 g) + 25–40 g protein

Final Note

With only 10 weeks remaining, prioritise performance and recovery over weight loss. At 73 kg, maintaining body mass while properly fueling will almost certainly lead to a better Ironman performance than trying to get lighter.