We should not shy away from asking whether doping has been involved in Ye Shiwen's extraordinary performance in the 400m individual medley but she is innocent until proved guilty

One of the big talking points in the media and over on Twitter was the observation that Ye Shiwen, China's 16-year-old 400 individual medley champion, swam the final 100m freestyle leg of her world record (4min 28.43sec) in 58.68, compared with the 58.65 by Ryan Lochte when he won the same event (time of 4:05.18).

Much can (and has) been made of this, and for many different reasons. The first, and the one that I will deal with right upfront, is what it implies about doping. It should come as no surprise that people will be suspicious. It's not just the fact that a world record was broken that arouses suspicion. It is that the record-breaker is only 16 years old, and has improved her time in the event by seven seconds since last year's world championships where she finished fifth in 4:35.

Also, and this has to be said, we regard swimmers from China with more suspicion. There are a few reasons for this and some of them, I do not condone. However, I do appreciate the suspicion — remember, this is the nation that produced a host of world-class runners almost overnight in the early 1990s. They came, they saw, the smashed world records that are yet to be challenged, let alone broken, in the women's 1500m, 3,000m and 10,000m. Then they vanished almost as quickly.

In the pool, history teaches us to be equally skeptical. Just this year, a 16-year old Chinese swimmer tested positive for EPO. In the 1990s, the same thing happened for swimming as happened for running — came, saw, conquered. But in that case, they got caught and then disappeared.

The doping allegations of the 1990s were largely confirmed by officials and sources who reported that doping within Chinese swimming programmes were widespread and institutionalised. That, in turn, would come as no surprise to students of the sport and doping. The practice of institutionalised doping began east of the Berlin Wall in the 1960s, and when the Wall fell, it just went further east.

The result is that Chinese performances will always be viewed with suspicion. In exactly the same way that a Tour de France leader is suspicious because of the history of that jersey, a Chinese world-beating athlete is going to face questions and suspicion.

So I will be upfront here — when I see such remarkable a) performances b) improvements in a short time and c) pacing strategies in a 16-year-old, I too am skeptical. It's human nature, conditioned by human behaviour in sport, and I think anyone who follows the sport understands the thinking process here.

However, that is NOT the same thing as condemning someone as a doper, and I would not do that based solely on performance. I would, however, be asking the same question I think many are, and I think this is only right. We should be suspicious, because history has shown us up more than once before. Does anyone who knows China's ethos and attitude towards Olympic sport actually believe that they would NOT deliberately dope their young athletes to win medals? If your answer is no, then I'm afraid you're naive, just as we'd be naive to believe that any athlete, regardless of nationality, faces huge temptation to dope.

That doesn't mean they do it though, just that they might, and so what we need to avoid is to paint everyone with the same brush, and so let's ask, without reaching a verdict. Just yet.

But let's just talk about the pacing, and the fact that this young Chinese swimmer can finish a medley as fast as Lochte did. It has some really interesting implications, and I'm going to talk about those instead of doping for now.

I'm a "student" of pacing strategies — they were a significant part of my PhD, and so I read a great deal into the physiology and implications of how athletes pace themselves.

So truth No1 — our ability to finish fast is a function of how much "reserve" capacity we maintain during the race. If we are racing maximally, at world record pace, for example, then we do not produce super-fast sprint finishes. Think of a 5,000m runner at world record pace with one lap to go. He is not going to blast a 52-second final lap.

Now consider the same runner, same distance, but running 30 seconds slower in a tactical Olympic final. They can run 52 seconds for the final lap, because they have a physiological reserve. The point is, our finishing speed is a function of the difference between our best performance potential and what we are actually doing — the closer we get to our best, the slower we finish.

Overall, the best performance comes from making sure that reserve is as low as possible. That is, you will perform your best when you have the least reserve at the finish. Put differently, if you have a big reserve at the finish, your overall performance is NOT as good as it might have been.

So, that's a long-winded explanation, let's look at what it means for Shiwen.

First point, we're talking about a medley here — 100m each of butterfly, backstroke, breaststroke and freestyle. Because there are different strokes, any comparison we make between Shiwen and Lochte may be affected by the relative strengths of the two for the freestyle stroke. You might be comparing an exceptional freestyle female swimmer in Shiwen to a fairly mediocre male freestyle swimmer in Lochte. If that were true, then similar times at the end would be no big deal.

But that's NOT the case here — Lochte is a good freestyle swimmer. An hour ago, he did a 47.74s 100m relay leg. It didn't win gold, but it's right up there, at most only a second off the very best on the day. Shiwen, on the other hand, is clearly an exceptional freestyle swimmer, but is not in their relay teams, and nor does she do any individual freestyle events, so she's not at the kind of level that would destroy world records (which is what it would need to be to make the comparison invalid). I'd argue that they're probably very similar, relative to their peers, at that stroke.

So I think it is safe to say that at best, Shiwen may edge Lochte for relative strength in the event, but not by much, and so she is comparable to Lochte for the specific stroke. Therefore, a direct comparison between Lochte and Shiwen for the freestyle leg is not invalid — it can be made without the confounder of relative freestyle strength.

Next, you look at what is "typical" in the 400 individual medley race. For men, the best swimmers typically close in 57 to 59 seconds (check splits from London). This is about 19 to 23% SLOWER than the best men finish in an isolated 100m freestyle.

For women, the TYPICAL (excluding Shiwen) final 100m freestyle takes 61 to 64 seconds. This is 18 to 22% slower than the best females swim 100m freestyle.

So the sport shows that you have a normal pattern, a typical ratio of medley freestyle to best freestyle — they SHOULD BE between 18 and 23% slower at the end of a 400m IM than in a 100m freestyle by itself.

Yet Shiwen is not. She does a 58.68s final leg, which is only about 10% off the best 100m freestyle swimmers. The conclusion that I would draw from this is that her 100m freestyle leg is disproportionately fast not only by comparison to Lochte, but also to her peers, and to the best 100m freestyle swimmers.

The only way to interpret that is to recognise that the physiology of a fast finish tells us that she must have a significant reserve for that final leg. It says that her first 300m was an extremely conservative effort. The simple question is: "Under what circumstances does a female have the capacity to finish a race as fast as a male?"

To answer this, think back to the key concept — finishing ability is a function of how close we are to our potential. To finish as fast as Shiwen does, relative to an unfatigued, isolated 100m freestyle, implies that she has a lot more potential in the event than was realised with her world record. The fact that Shiwen could close as fast as Lochte suggests to me that her efforts over the first 300m of that final took very little out of her.

If that is true, then her overall performance is a significant underperformance. The allocation of energy over the course of the race might be debated, but what physiology suggests is that it should probably be more even for Shiwen, and it would allow her to swim quite a lot faster than the 4:28.43 that she did.

Now, at this point, many will say "maybe it's just her way to finish fast", and that may be true. You'll find examples of athletes who just had more at the end, and of course you get ranges. But the range is 18-23% off the isolated performance, not 10%. That's too big, and it's not the optimal way, based on everything we know about performance and pacing. I suspect that Shiwen would probably be 2 or more seconds faster if she went out harder and pushed to the point of fatigue. It would force her final leg to be slower, maybe 62 instead of 58.6 seconds, but the gaps would have been created early.

Scary thought then that there is a "reserve" there that would see her get even better. It would only cause more questioning though — imagine a strong world record of 4:30 lowered by five or six seconds by a 16-year old?

Interesting times. Again, to stress the earlier point, this is an interesting discussion. And the doping aspect is important (don't shy away from the question just because it's politically incorrect — look where that got sport before), but this doesn't prove anything. So let's wait and see.

This is an excerpt from an article on The Science of Sport website