I did say it is subjective as we have no mechanical way of measuring.

But in general terms, what i am trying to explain that if you do several hours of training (or a reasonbly long workout like a 2.5 hrs workout in each sport), the average intensity will end up highest on the swim because most people cannot swim easy enough to bring down swim intensity during easy swim periods. I was not trying to compare same intensity across sports. I agreed that for the same intensity, more weight bearing will result in more overall energy burned.

All the reasons you point out for the swim-bike workout subjectively feeling harder are somewhat valid, but I ran these camps for something like 15 years and have observations from many athletes, over multiple workouts over multiple years. I know you guys want a contained study, and I can't offer that. Some observations over many years from the real world.

I think you guys need to listen to what Erikmulk is saying. I get that this board will be biased a bit towards bike-run. The down side is triathletes generally under estimate the workload from their swim in races and swim in workouts. It is likely much larger than they give it credit for.

Do the three standalone workouts of 2.5 hrs each to get a better subjective observation removing all other sports. Do them all tapered and rested. You won't be able to get the easiest swim intensity low enough to not get less gassed compared to an easy bike intensity or even an easy run intensity (as you can always walk). Easy swimming at some point you just drown.