Any good endurance athlete will say ..

With 100 metres left, there’s really no thinking, it’s just endurance and just focusing on the pain and trying to ignore the pain at the same time, which is a strange thing. You’ve got to focus on where the pain is and try to eliminate the feeling of fatigue and really just focus on maximizing each stroke, which is a difficult thing when everything’s on fire.

As far as the pain goes, you’ve got to keep pushing it or do I choose to relent and give in to my body’s reaction to working too hard?

The test of an endurance athlete is to push that limit and push that boundary and tell the body it’s got to sit tight a couple of minutes as you see how much you can do.

Any good endurance athlete will say that maintaining their form and their technique through those moments of pain and fatigue is probably the most key aspect to maintaining the speed. It’s really easy to break down the technique and not to be as snappy to return to the setup phase in the kayak stroke.

Adam van Koeverden, Oakville, Ontario, Toronto Star, 21 August 2008

k1-500m Final - 2004 Olympics
sportsscientists.com have a great post on Pacing strategy - how good pacing wins gold medals ..

Now, we know that in virtually every single type of sport, as soon as the event lasts between 3 and 5 minutes, the optimal pacing strategy is a fast start, then a slowing in the middle and an increase at the end, so that the two halves are close to even, but there is an "inverted U-shape" . This is why the first and final laps of mile and 1500m world records are significantly faster than the middle two laps.

When races are short, like a men's 400m or 800m run, or the men's 200m or 500m kayaking event, then it's different - the best strategy then is to go out hard and accept some kind of deterioration at the end of a race. Longer races, like men's 5000m and 10000m running events, the marathon, the Tour, all benefit from even pace, or even a slower start, with an 'endspurt' in the final kilometer. It's not co-incidence, for example, that in 24 of 25 World Records over 10,000m, the fastest kilometer has come at the very end of the race!

[..] for an event lasting 3 to 4 minutes, like the [..] K1 1000m kayak event, the optimal way to race is to hold reserve over the first half and then finish almost as fast as you begin. [..]

And we are not so different that each individual has an optimal pacing strategy. Yes, some are better at sustaining faster starts than others, some are better at kicking later in races. Much of this is psychological, I feel, but there are likely physiological reasons too. But these physiological differences are not so large that anyone can get away with vastly different strategies. For some reason, Germany have figured this out and are winning races that physiologically, they might otherwise have lost.