Triathlon Turn Buoys

by Duane Dobko [Source: East Coast Cycos newsletter in Tri-Rudy newsletter, December 2, 2008]

Why are turn buoys so important in open water triathlon swimming? After all, they are few and far between (there are usually only 2 turns in an entire race). The logic would suggest that they are inconsequential, which couldn't be further from the truth. It is not the time to go around a turn buoy that makes them so important. Instead, they are critical because they create an "accordion effect" which can split a whole race apart and separate the winners from the contenders.

A turn buoy in a triathlon swim is analogous to a construction zone on a highway. It is pure gridlock upstream as the number of lanes and speed limits are reduced. At the construction site itself the cars move in slow, uniform procession. Once through, all of the sudden there is a huge path of open road in front. All those cars that were bumper to bumper ahead are now on the horizon. This model happens in identical fashion in a triathlon race at every turn buoy. The only difference is that when you are swimming, you cannot see around you enough for it to be obvious.

As you are turning around the buoy, you must reduce your speed to zero. This is because you are turning, and no longer trying to move forward. This creates problems for the swimmer immediately behind you. That person wants to keep swimming forward, but cannot because you are in their way and traveling at zero speed. This forces them to slow down, which forces the person behind them to slow down, and so on. When you complete the turn and start moving forward again, the person immediately behind you is in the process of turning and traveling at zero speed. Thus, when they complete the turn there is a gap equal to the distance you swam while they were turning. The next person in line also has the same gap, and so on.

So, why does this matter? After all, the gap between you and your competitor behind you after a turn is not much. The distance is usually 5 feet. But 5 feet is enough to fall out of a draft zone in the water. This means that the person behind you, who was once able to keep up to you with little effort, now has to work much harder to maintain the same speed. This is what makes turn buoys so important. The person behind you has two bad choices. One, they can sprint as fast as they can to catch up to you and draft again, which risks cramping and fatigue. Or two, they are forced to swim without your draft, which causes them work much harder and slower and get tired more quickly.

Thus, the importance of the turn buoy is not the raw time to turn. Instead, turns affect the entire dynamic of the race and determine who wins and who gets left behind. If you know how to turn well and know what to expect, you can make significant improvements in your race times without any improvement to your swimming ability. The pros are aware of this importance. I encourage any triathlete who gets to watch a pro race observe them closely swimming around turns.

Here is what the professional triathlete is doing while leading the swim. They take the last 100 yards or so into a turn slowly. This forces everyone behind to bunch together. Thus, when they get to the turn and reduce their speed to zero, the slowing effect for everyone else is greater. It also allows them to rest and prepare for the turn itself. They get around the turn as fast as possible and then just hammer with everything they have after the turn and for the next 10-20 yards. We are talking a flat out 110% effort with the pull and kick. This maximizes the gap and forces the other competitors to sprint that much harder and longer to catch up. If the leader can sprint well, they can leave the field in the dust, even if their competitors are better distance swimmers.

Here is what happens next. Almost every time the last couple of swimmers in the pack get dropped. They are forced to slow down way too long and lose too much ground to catch up again. As a result, they are stuck breaking their own water for the rest of the race. The swimmers in the middle of the pack form their own smaller group, and a few leaders emerge at the front; sometimes swimming alone, other times drafting in a line. This dynamic is usually most significant at the first turn as the field is closer together at this point. However, I have observed races where the leader intentionally keeps the field together on the first turn, only to blow them all away on the final turn knowing that the fatigue is greater which improves their chance to break away.

The dynamics of turn buoys are important to more than the pros. For the weekend warriors, the last 25 yards into a turn buoy can be a jumbled mess of people with arms and legs flying around all over the place and going nowhere. It is often as violent before a turn buoy as it is just after the start of the whole race. It is important to pick the right strategy. Swim into the crowd at this point and you will get stuck for certain.

Swim to the inside of the buoy and you have a high risk of getting stuck, but with potential to gain on the entire field if you don't get stuck. Swim to the outside of the field and you go around the turn much slower, but have very little risk of getting caught in the pack. "Inside" means that you are hugging the buoy as close as possible during the turn. "Outside" means that you are swimming the long way around all of the other swimmers bunched around the buoy. There is no right answer as every situation is different. However, you must be aware of the process in order to make the right choices consistently.

For most people (weekend warriors and pros alike), I recommend to take a crowded first turn buoy to the outside of the field, even though it is longer distance. The reason is that it carries the least risk. If there isn't a large crowd, by all means take the inside and get around it as fast as possible. The worst thing that can happen early on in a triathlon swim is inhaling water or taking a black eye. Swallow some water right away means you have over half of the race left to go and have lost your concentration. It is not a good time to take chances. A better option for taking the inside is the last buoy. At this point, the field is spaced further apart and so there are less flying arms and legs to hit you. Also, if the worst does happen, you don't have so much of the race left to swim and don't lose as much time or concentration.

Turn buoys make open-water swimming unique from pool swimming. Pool swimmers race at a relatively uniform speed and effort. In a triathlon swim, you need to swim at your best-mile pace for most of the time, but also need to be able to sprint at your best-50 on demand. It is the athlete with the best combination of sprint and endurance swimming abilities that usually prevails in a triathlon swim. If it were not for the turns, sprinting ability would matter much less.

The best way to prepare for turns in triathlon swimming is to work on sprinting in practice. You can gain the same amount of race time working on your sprint ability as you can by working on your endurance. If you haven't worked on sprinting in the past but have worked a lot on endurance, you stand to gain a significant amount of time by learning how to sprint.

In summary, this article has covered why turn buoys are important in an open water triathlon swim. The change of direction in a turn creates an accordion effect which forces you and your competitors to speed up and slow down in the water. If you understand this effect and have trained properly, you can make big improvements in your overall race times.