Difference between a Ironman Triathlon and an ultra distance running event (longer than a marathon)

I often get asked what is the difference between an Ironman Triathlon & Ultra distance race
Below is brief history about me and my personal observations as an Ironman, ultra distance running competitor and coaching athletes to compete successfully in an ultra running event after an Ironman triathlon competition or completing 140.6 mile triathlon then preparing for an ultra distance running events.
Mark Kleanthous sporting histroy
Total races since 1981                                                       1,050+ 
 Ironman distance races completed:                                       36
 ½ Ironman distance races  also known as 70.3 completed: 80+
Double Iron & Tripe Iron distance                                          4+
Approximate # ultra marathons completed:                           30
Longest ultra distance race finished: Triple Ironman 45 hours 58 mins 29 grueling seconds – no sleep no break no stopping
How long have you been doing Ironman Triathlons? 
Triathlons since 1983 first iron distance 1984 so this year will be my 30th season 
Ultra running?  Marathons since 1981
Longer than a marathon 1983 >30 miles 50 miles 100km 24 hours
Marathon Des Sables (150 miles in 6 days) 
Q1: Do you primarily consider yourself a triathlete, an ultra runner or something else?
I consider myself an ultra distance endurance athlete having done 1,050 events world wide of which 460 were triathlons.
Q2: What similarities do you find in both sports?
The ability to keep focused and knows my limitations allow me to complete both IronMan triathlons and Ultra distance running events
Q3: What differences have you noticed in these two different types of competitions?
Ironman is competitive few would stop to help you
More camaraderie with ultra distance running which is similar to double triple iron man events 
Q4: from the training process to the race itself, which do you think is more challenging…a 50 mile mountain ultra or an Ironman triathlon?
50 mile is more challenging and I come from a running back ground (2:24:40 marathon & have run 6:19 for 50 miles.
 Single muscle groups for long periods of time and the jarring effect make it much harder during and post ultra distance events
Q5: What aspects of Ironman training or competition do you think ultra runners are sometimes oblivious to?
The ability to be good at all 3 sports.
Knowing different limiting factors and max HR for swim bike run.
Cold in swim skills required on bike and hot in run when already depleted and partially dehydrated before you even start the 26.2 miles
Q6: What aspects of ultra marathon training or competition do you think triathletes would benefit from?
Learning to pace themselves when they start the marathon due to energy levels already depleted.
Q7: What is the typical training week look like 3 months out from your Ironman? How does it compare to your preparation for an ultra in the same timeline?
Now aged 53 I taper more with the running than I use to for a triathlon while still keeping up the volume.
Ultra Running
I cross train using row machine cross trainer in final 4 weeks all running I do is @ predicted ultra distance pace with or without back pack that I will use in the event
Q8: What is your advice to Ironman triathletes who are considering their first ultra?
Continue to cross train to prevent injuries and focus more on swim and cycling in final few weeks during the taper this is when you can be at high risk of injury.
Q9: Please describe yourself in 3 key words.
#1 Never Give Up – Almost true of 1,050 races 
Well almost I have 3 x DNF 
(Hit bar car during triathlon that broke my bike – crashed at MTB grand Prix downhill ended up in hospital – was ill after 4 hours of 10 hour race stopped) 
#2 Determined Tenacious and Experienced
If you need coahcing for back to back Iron man & ultra distance running events please cotnact me