Thanks guys, good stuff here.
So it’s pretty clear that being lighter helps, with the run being the area which is affected most.
For the posters who have shared your results, you’re all quicker than me so that gives me hope!
I am still heavier/more dense, with a higher BMI, so the uncomfortable truth is probably that unless I’m prepared to sacrifice rowing and crossfit I’ll not be able to perform at a decent club/age group level.
Regarding the lower leg circumference thing, I first read about it in David Epstein’s book ‘Sports Gene’ which explores some of the physical attributes in top level sport.
Some is obvious, like height in basketball, others not so much- like eyesight for baseball.
The Kalenjin tribe punch above their weight in distance running, and the evidence seems to support optimal running economy due to thinner and lighter lower limbs, plus optimal Achilles length (which affects the size and shape of the calf muscle).
He also talks about their long limbs being very good at dissipating heat generated from exertion. A great comparison is Paula Radcliffe who was in form going into the Athens Olympics but didn’t perform to expected levels as she couldn’t cope with the Athens heat.
There are a few studies about morphology around legs, muscle and insertion points etc…
I may be your closest comparison but you’re still heavier. I was in bodybuilding prior to triathlon and entering the sport I was 84kg at 177cm at 10% bf. For reference at entering the sport I had a 43" chest, 24" thighs and 16.5" arms. I wasn’t that strong with a max bench around 275, squat 315 and deadlift around 365.
Entered triathlon 4 years ago and my cycling was extremely good from the start. My first Ironman bike split was 4:59 at Cda which is a very slow bike course.
Not to go into too much detail but as I got more into triathlon I stopped lifting. I barely went to the gym in 2018 and in 2019 I only went with my gf doing frou frou exercises. Despite this I lost minimal muscle and was 77kg at 8%bf with 42" chest, 15" arms 24" thighs.
Dec 2019 I didn’t to get back into lifting but low reps to try and improve on my cycling again and after 6 weeks I had a 335 deadlift and squatting 275 for reps while I am also doing 17hr/week endurance training so my legs are always fatigued so I could probably jump those up pretty quick with some rest. I am now presently 78kg at that same 8%bf.
For triathlon reference, on tough courses I have done a 9:45 Ironman and 4:29 70.3 and I am much fitter now than then. I have around a 22min 1500m, 17:30 5K, 1:21 half marathon know I’m capable of a sub 3hr marathon.
If you keep your protein high, have a good diet, you can maintain most strength while still making large strides in endurance sports. This year I hope to go sub 9:30 for an IM and 4:20 for a 70.3 while looking jacked and lifting heavy(ish lol)