That was quite misinformed and very old-school advice. Particularly if--as is the case with most triathletes when racing--you might be wearing a wetsuit.
Except for those who swim with very high efficiency--elites and those pretty close to that status--kicking more will only increase turbulence/drag and energy waste. It will undermine, not improve, your swimming. You can almost never go wrong by kicking less!
The best convincer will be to try kicking as she recommended for just a lap or two in practice (25y/m) and compare how you feel doing that vs. using your natural 2BK. Then ask yourself if you'd like to attempt it for 400m in open water with no pushoffs to recover from the kicking effort--before needing to really rely on your legs from quite a bit longer on land.
If you perform this self-test in practice, please share your experience and conclusions here.
Head Coach & Chief Executive Optimist
May your laps be as happy as mine.
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