Advice needed for first Ironman.
Im a 20 year old guy hoping to complete my first ironman the 20'th of August (Copenhagen), Im training alone and have some questions regarding my training which have started to worry me.
1. What time should I realistically aim for? (Cut off is 15:30 hours)
2. How do I deal with not being able to hit the desired training zone (eg. 86% mhr) during bike and swim
3. Should I consider making my programme less intense in terms of intervals?
I've always been fairly athletic, I did karate when I was a kid and finished my first marathon when I turned 16 in 4:45 with 2 months loose training prior. From I was 17-18 I went loosely into triathlon, learned how to swim with a 1:50 pace in a circular 100m pool for 2km, bike 100km (62 miles) averaging 25-28 km/h and also set some decent run times such as a half-marathon in 1:31 and 5km in 18:30 and similar.
In august 2015 I did a half-ironman (after 6 months without training) in 6:12 finishing in a relaxed manner.
1,5 years after finishing my half-ironman (and with no real training in between) I started training for KMD Ironman this february as I have time on my hands for the time being. In February I had 17 hours of training (split over 2-3 weeks), In march and april I averaged 8 hours and 8,5 hours per week on average. Here in may it's closer to 9-10 hours on average. That's roughly 331 km running (205 miles), 1165 km of biking (723 miles) and 27km (17 miles) of swimming since february. Fitness wise my vo2max is around 60 now (used to be 65-67).
I've gotten a bit worried recently as I can't hit the desired training zones when I need to do hard intervals on the bike (eg. 6x5 min 86%mhr? After training I always get a restitution meal of roughly 75grams of fast carbohydrates and 25g proteins (chocolate milk) and I try to eat a lot of healthy food during the day. Is it my diet or something else?
In my programme im supposed to be doing 12-13 hours of training at this point as well, which im averaging under. I make sure to hit most bike and run workouts but in a week it's not uncommon for me to miss some swimming, stability training, gym, stretch etc. which eventually adds up (due to work and motivation). On a bad week I might miss one important workout like last week where I had to skip my long bike+run brick (probably happened 3 times since february for different reasons).
How should I deal with this situation? I considered focusing hard intervals on running and just doing treshold (below 85%mhr) intervals on the bike and does it sound like I should train to complete in 15 hours? 13-14? less? My original hope was below 12, but since I can't do all the hard intervals and have to skip training now and then I suspect 13-14 would be more realistic?
Any help is highly appreciated!