How to pace/execute a IM distance event

Often called an Ironman, IM or a full distance, this event/race is a longer distance, lasting from top age groups at early 8.5 hours to the cut of time of 17 hours. So you have to wise and honest with your goal/intention or the race course itself as to how you treat. This info sheet is all about the race day strategy to try and nail a well executed pace/effort throughout


PRE Event/race

  • Acknowledge the event it self. Is it hilly/flat or off road
  • Does it play to your strengths
  • If you did a rough estimate being honest will you be closer to 8.5 hours or to the 17 so you know what to do on the day
  • Look at the course pre race so you can see Key markers such as aid stations, distances achieved etc so it can factor into your planning
  • How is the weather looking? Will it affect the day

Warm up

Include time to have a warm up to mobilise the joints, pre pare you mentally and also to get he blood moving around the body and the HR to become ready for the start. DON’T go off cold!

The Swim

Know what you have ahead eg a sea swim or lake/river swim. Look at the course before heading to the event and also on race morning to know where the bouys/exit/entry is. The weather may also have a deciding factor and add additional challenges. From your training you will have a rough time for how long it will take, always allow a couple of minutes each side of this time for the course and conditions as its very rare you will be the same time on all courses.

Its difficult to look at pace/HR/distance while swimming so the Key scale of effort to work from is RPE (rate of perceived effort) (1-10, 1 being rest, 10 being a 100m sprint)

Typically the swim start will always be slightly higher in efforts o aim  for a RPE of 6-8 for the first 1-200 metres. Keep it for only a short period of time. This is also the only time of the event to go above a 6 out of 10 due to the duration of effort

60 mins or lower – The RPE can stay around the 5-6 of out 10

60-90 mins  – It would be a good idea to go to a 4-5.5 out of 10 as your going for longer

90 mins – 2hrs 20  – It would be a good idea to go to a 3.5-5 out of 10 as your going for longer still


Transition 1

Control the effort after the swim, dont build up lots of lactic acid and stay calm, save the energy for later in the race. Be sensible basically

The Bike

Again know your course and have a rough idea as to how long it may take. The intensity of a 4.5 to a 8 hour bike will be different due to the extra time taken. We don’t want you pushing off too fast worried about time, only to then just be surviving by the end with a long run after

Target time 8-9 hours

  • 78-80% FTP Power
  • 87-90% Threshold Heart rate bike
  • RPE 5.5-6 out of 10

Target time of 9-10 hours

  • 76-78% FTP Power
  • 84-86% Threshold Heart rate bike
  • RPE 5-5.5 out of 10

Target time of 10-11 hours

  • 74-76% FTP Power
  • 83-85% Threshold Heart rate bike
  • RPE 4.5-5 out of 10

Target time of 11-12 hours

  • 72-74% FTP Power
  • 81-83% Threshold Heart rate bike
  • RPE 4 out of 10

Target time of 12-13 hours

  • 70-72% FTP power
  • 78-80% Threshold Heart rate bike
  • RPE 4 out of 10

Target time of 13-14 hours

  • 68-70% FTP power
  • 68-70% Threshold Heart rate bike
  • RPE 3.5 out of 10

Target time of 14-15 hours

  • 66-68% FTP power
  • 73-76% Threshold Heart rate bike
  • RPE 3 out of 10

Target time of 15-17 hours

  • 60-66% FTP power
  • 69-72% Threshold Heart rate bike
  • RPE 3 out of 10



Downhill the goal is to use your skills and ease off at the right time, let your momentum take over more

Uphill. On short sharp then you sometimes have to work as hard as you need, but in general try not to go above threshold of FTP/HR or a 6/7 out of 10. The goal is 85-90% Of these values


Winds and weather

This can make the bike more interesting and here are some key elements to help you pace it right

  • Wind with you, back off the power/effort a little and pick up the cadence to help the legs recover as use the wind as free speed
  • With against you, add a little gear and let the intensity ride up to the top end of the target effort. The lower gear will keep the HR a little lower

Transition 2

Be smart, jog or control the effort. Go through remembering you want to set yourself up for a good run


The Run

  • Being the final leg you still have 26 miles on with fatigue in the body, after a smartly paced bike effort. you have been racing for anything between 6hours+ now. So again be smart! watch the pace out of T2 and if anything hold back a little in the first 2-3 km to make sure you can take stock of how your feeling.
  • Often lots of athletes feel amazing and get carried away for the first few miles only to have to walk a lot of the later stages
  • aim to head out at a lower effort to make sure you feel good at the later stages
  • A target of 79-83% Threshold HR for athletes aiming for sub 10-11 hours or RPE 4
  • A target of 75-80% For all other athletes.
  • Regular walk breaks such as these, run for 9 mins walk for 1 min, or 4-1 of the same or walk through aid stations have become very effective and help balance energy whilst still being able to take on the fuel you need

Now to go make your plan and enjoy the process


Good luck


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