miklcct,I have a soft spot for you because you are an enthusiastic young guy full of dreams and you are from Hong Kong,which is where I was born and learned to swim BUT seriously,the biggest thing that is holding you back is not realising how little you understand about long triathlons and long distance open water swimming.
Read what SnappingT has written and take his advice.....oh and watch this video of Aussie Ultra legend John van Wisse and his Enduroman Arc to Arch event. He is an old school hard man if ever there was one.(Weighed about 92kg when he did this event) https://vimeo.com/113491266
I have two dream swims - one is round Hong Kong, one is the English Channel. In the perfect situation I should do the round HK swim February / March in the same year before I do the Channel as a "test run in my comfort zone". However due to cost reason (it is too expensive - 2 times the cost of doing the Channel) I have decided to skip the HK swim unless Hong Kong is liberated.
And I still don't understand what's wrong with my "triathlete mentality" as from the very beginning I train in the a triathlon club and train both swim and run. Also the two Channel swimmers I know currently living in the city also train in the triathlon club I trained with as well.
This is a general question for this thread and maybe it was discussed 7 years ago, but now that swimming wetsuits exist, why don't they just open up a wetsuit category. It won't cheapen the old school category, but would open up the "event" to a lot more smaller and lean athletes who otherwise are on the limit. If you get to 5'9" and 137, I bet you DNF just because you can't possibly generate and keep enough heat around your organs.
I did a 12km Lake crossing swim last summer and it was borderline Ironman wetsuit legal temp. One of the women from my club who beats me by 1.5 min during the 1500 free in masters swimming went with no wetuit. She should have beaten me by around 10 minutes if both of us had no wetsuit. I chose to wear one for warmth because my intensity was going to be way lower on a 12km swim than a 1500m and I would just lose heat to the lake going at tourist marathon pace. I ended up beating her by over 35 minutes. I should have just beaten her by around 10 min (if you take wetsuit into account for 10% speed). But she got hypothermic half way through. She was borderline medical but as soon as she got on land with air temp at 30C and warm food she stabilized. She was barely 5'2" 120 lbs. I am 5'6", 140 lbs. I made the right call, because I have a lot less body fat.
I think Global Swim Series has it "right" with wetsuit and no wetsuit options.
Gibraltar has traditional and neoprene categories. There is one Hongkonger done the neoprene category but none in the traditional category yet. It is one of the channel in my secondary bucket list (my primary bucket contains the English Channel and round Hong Kong), however I am not fast enough to qualify for it (it requires 3 km/h for 4 hours for a single crossing).
I also did a lake crossing of similar distance last year and the water temperature was 20 - 22Â°C. I went for the skin category and it became my first marathon swim. I really enjoyed it and continued to do marathon swimming afterwards. However, now in summer I basically have stopped most of my training because I just can't tolerate the heat to do any structured programme so I have decided not training in the squad anymore, and wait until November to return when the temperature goes under 24Â°C. If I get to 5'9" and 137 I will train at a higher intensity than last year as well. I want to get myself to the slimiest I can get in order to get the speed up such that I can complete the crossing as fast as possible. I will get my feeling in the coming winter to decide.
Also can anyone suggest how I can lose weight, considering I can't train anything high intensity because it is too hot in the summer? My weight hasn't gone down in the preceding few months. 137 was my weight when I graduated from uni but after a year of unhealthy lifestyle afterwards it went up to 156, with significant deterioration in my aquathon performance as well, and I could never get rid of all those extra weight since then despite adding heavy swim training (averaging about 15 km / week over a whole year) afterwards.
Like anything that involves endurance, for the same heart and lungs and cardio system, feeding less mass with the same oxygen is better....but in swimming you have this buoyancy trade off, where more fat floats you better, meaning you have less drag in the water. So YES you have to feed more mass with the same fixed cardio systems, but because you're floating better you have less drag if you are fatter. And that's just in pool temperatures. Now if you drop the water temp a lot, you have the entire heat loss thing that comes into play. I don't think getting to 137 lbs at 5'9" will help you for the channel swim, but it will help you if you run an open marathon where weight means you have to do more work at the same pace with the same cardio system AND you have a big cooling penalty for running. Its why Eliud Kipchoge is 5'8" and 115 lbs . He would need to gain 50 lbs of fat to get into the right body composition if you knew how to swim to do a channel crossing.
I THINK think Jan Frodeno would not be able to finish a channel crossing swim even though he is an excellent swimmer. I THINK he would just DNF from hypothermia. Having said that if he set out at channel crossing world record pace which is around 5 kph, he just MIGHT generate enough heat to stay warm enough for 7 hrs. That's why I THINK he would DNF. My guess is his body composition relative to his pace is right on the border line. Only way Jan finishes it is he keeps the pace super high and generates enough heat to net get hypothermic...he's otherwise too lean.
Otherwise its a simple thermodynamic equation. You lose X joules of heat from your body per second, so you need to generate almost 100% of X joules internally in heat (80% of your energy goes into generating heat, 20% into mechanical work....X = your heat generation). The slower you swim, the more mass you need to survive. The faster you swim, you can have less BMI of which less can be pure fat.
This is why neoprene allows low body mass athletes with low % fat to still do cold water racing. Its really just physics. I don't think its wise to be super lean and go into long distance cold racing. Too much risk. There is not that much you can do to defeat physics and thermodynamics other than work with those aspects of science. We can't will ourselve against science hoping our bodies can adapt. They can, but only a bit.