Swimming usually accounts for 10 percent or less of total time in a triathlon. The 90 percent of the race that happens on dry land has far more potential to influence your outcome, in time or place.

But the swim has outsize influence in two areas:

1) The swim experience is so harrowing – particularly for a first-timer – that it takes away much of the pleasure of the overall experience . . . or may  discourage you from trying another.

This happens because (a) you feel unable to exert control of your body, flailing helplessly or (b) you feel deeply vulnerable –  trapped amidst a sea of densely-packed flailing rivals in deep water. The resulting sense – something between anxiety and panic – will leave you needing to clear adrenaline from your bloodstream back on land when you’d rather just send fuel to your muscles. Not much fun and not good for your ability to ride your best.

2) Even if you finish the swim without having felt anxiety, you worked so hard that you feel drained for much of the race.

This is because you’ve got a finite number of “heartbeats to spend” over the course of the time it takes you to complete the event. On land – because of gravity, heat and hills – there will be many times when you’ll have little choice but to spend more heartbeats. The water is the only part of the race where ‘saving heartbeats to spend later’ is a viable option. It’s also the most strategic option for any triathlete who did not grow up swimming competitively because while it takes only a few more heartbeats to run a little faster, it takes a LOT more heartbeats to swim a little faster.

The key to success in running and cycling is training to get in better shape. The key to optimizing your triathlon swim is practice that:

(1) Maximizes physical and psychological comfort; and

2) Minimizes energy output.

This video clip illustrates both.