going to give it a rest until Im under 100 kegs

After converting your numbers to lbs, I agree that running at that weight is probably counter-productive.  I blew out both my knees is less than a year trying to run at that weight.  But your "start back running" weight is too low IMO.  I ran 5 marathon, completed two IM and done many sprints and Olys in the 240 - 260 lbs (109 -118 kg) range over the last 12 years.

Keep swimming and biking and working on your weight and you'll be back out on the road in no time at all.

~Mike

thanks Mike, you are probably right.. If I lost 30kg I would probably revise that weight limit. 

Nothing wrong with being smart and thinking long term man.  I think you are doing the right thing by focusing on the weight first.  I broke my right femur in a car accident and long story short, I have a steel rod in my right leg with the top of it broken off inside my hip.  Prior to doing any serious exercise, I also lost some weight.  It was the best approach.

You will have a big advantage over the route I took.  I simply used a recumbent exercise bike as my exercise plan.  I wish I had also used swimming and a real bike outdoors. 

Best of luck but know that you are still tri training and we are right there with you. 

Have you considered any strength training with a focus on core strengthening? Think adding that will have a twofold result, added strength focusing on you weakness(back) and helping with weight loss.

Don't be down on yourself. YOu are still working towards a goal, it's just more of a weight loss one than tri's for now.
I"m not sure how tall you are so I'm not sure how good 100kgs is as a goal.  at my height I can do many things at that weight, but I'd rather be lighter also ..

all the best

thanks everyone for the words, much appreciated.

a lot of people have been telling me to work on my core.. I was thinking my core was becoming very strong.. when I poke my stomach I can really feel hardness that has never been there before.

I am 6'.. so my weight puts me into the morbidly obese range.. that is always good.. haha. But I believe I have a higher percentage of muscle.. I was a serious gym jockey for a few years before getting into this, and have been able to maintain good muscle mass. Like I fit into XXL 2XU tri gear comfortable.. my chest measurement is larger than my waist.. dont really have a big gut or anything..

my swim time for 750m is around 18 minutes.. I can swim easily for a mile non stop at this speed. I can regularly do 20mph average speed for 20/40 km rides in aero position.. I just need to lose some body mass.. it has to go.

ok, Im rambling now.. lol

Im not really down on this.. I think I just need to readjust goals.. not down and out, just back to the drawing board.

While your abs may indeed be firmer and stronger, there is more to your core than just your abs.  Hip flexors, hamstrings & quads (to an accessory extent), transverse abdominus (wraps all the way around), lower back muscles, etc and so forth.  All of THAT makes up your core.  When you have really worked to strengthen all of those, you will see improvements and extra support to help prevent lower back issues (says the girl with 3 bulging discs...)

Somewhere here on BT is a group of core exercises called "Around the World" (I think I have a link to them in my log.  Check them out.

And take care of that back!

I wouldn't give up racing. I've dropped 100-plus pounds over the years and I used to say, "I'm not going to do this or that until I weigh this much." Then I thought that I just need to live in the now and start doing those things.

My two cents: Keep doing triathlon training, just s-------l-------o-------w down. Walk for 6.5 minutes, then jog slowly for 30 seconds. Slowly increase the amount you jog while decreasing the amount you walk every week or so. But you could still do the 5K distance, just slower. Best wishes!