Long Run with Sprint Finish: 90-Minute Aerobic Build

Session Overview

This long run builds your aerobic base and then demands a fast finish — simulating the competitive end of a triathlon run when your legs are genuinely fatigued. By spending the first 80 minutes at a genuinely easy pace, you arrive at the 10-minute sprint finish with real accumulated tiredness, training your body to hold race pace when it matters most.

What You’ll Need

  • GPS watch
  • Hydration — carry at least 500ml for 90 minutes in warm weather
  • A safe, preferably flat 10-12km route with a clear 2-3km finishing straight

Warm-Up (5 minutes)

Begin with 5 minutes of easy walking or very slow jogging. Dynamic mobilisation: hip flexor stretches, leg swings, ankle circles. No hard warm-up needed — the first 20 minutes of easy running serve as the extended warm-up.

Main Set

Run for 80 minutes at Zone 1-2 (conversational pace — full sentences throughout). Keep heart rate below 70% of maximum. In the final 10 minutes of the run, lift the effort to Zone 3-4 (approximately your 10km race pace). Hold this for the full 10 minutes despite the fatigue in your legs.

  • Minutes 0-20: Easy running — resist all urges to go faster
  • Minutes 20-60: Steady aerobic base — heart rate 60-70% max
  • Minutes 60-80: Maintain pace but check form: tall posture, relaxed arms
  • Minutes 80-90: Sprint finish at Zone 3-4 — race-pace effort on fatigued legs

Cool-Down (5 minutes)

Walk or jog very easily for five minutes immediately after the sprint finish. Do not stop suddenly. Stretch calves, quads, hamstrings and hip flexors for five minutes minimum. Re-fuel within 30 minutes with a mix of carbohydrate and protein.

Coaching Notes

  • Total session: approximately 95 minutes of movement
  • The key rule: the easy sections must be genuinely easy — grey-zone running defeats the purpose
  • In hot weather, slow the easy pace further and shorten the sprint finish to 7 minutes if needed
  • RPE for the sprint finish: 8/10 — breathing hard but controlled
  • This session pairs well with a structured bike session 24-48 hours later

Training at your own risk. The information provided is for general guidance only and is not a substitute for professional medical advice. Please consult a doctor before starting any new exercise programme, especially if you have any pre-existing health conditions.