Q&A with Olympic Swimmer Mack Horton

1. Can you explain what the standard anti-doping testing process looks like in swimming – for both an in-competition and out-of-competition test?

Testing and the way it is conducted isn’t specific to swimming, testing across all sports is carried out in the same way. The first step of the test is for a Doping Control Officer (DCO) to identify you (typically with a driver’s license) and notify you that you have been selected for a doping test. At this point they will notify you on the type of test – Blood & Urine, Urine Only, or Blood Passport. Once you have been notified someone from the testing agency must be able to always see you until you give a complete sample.

In my case, this usually means about an hour of them sitting next to the pool as I do laps. If the test is one involving a blood sample, the DCO will usually try and grab me before I get in the pool first thing in the morning as you are not allowed to have exercised for 2 hours prior and must sit still for 10 minutes immediately preceding the blood collection. Blood collection is always done by a pathology nurse. Once I am ready to deliver a sample (pee) I’ll be escorted to the set-up testing station (either a marshalling room if at the pool or my home bathroom if the test is at home). Athletes are given a selection of beakers to choose from randomly, this is to ensure they can’t be tampered with. During the test you must be bare from your armpits to your knees and the sample being passed must be visible to the DCO the whole time so they can ensure you are not falsifying the test.

Once you have delivered your sample you sit down with the DCO to separate your sample from the beaker into an ‘A’ and a ‘B’ collection vessel. These are basically just glass jars with lids that can’t be undone without breaking an internal mechanism which would identify the sample has been tampered with when it arrives at the lab. Athletes’ samples are then sealed in a single use plastic pocket and boxed away. At this point once the sample is sealed and the athlete is satisfied, the sample is under the responsibility of the DCO to have delivered to the testing lab. In Australia, I believe our testing lab is in Sydney. It is worth mentioning that at any stage before delivering a sample, athletes are free to inspect all vessels/seals/boxes/needles etc for contamination or damage and may decline using that particular one and exchange for another if they aren’t content with its appearance or performance.

Once the sample collection is complete, the paperwork begins. This involves contact details, date, and time of test as well as time of sample delivery, temperature (if blood), a questionnaire around altitude training or extreme heat stress in the lead up to the test, ensuring sample numbers are correct on all aspects of the test (collection vessel, paperwork – sometimes handwritten, sometimes a sticker kit). The specific gravity is also recorded, this is a metric that measures how hydrated you are, and it must be above a threshold otherwise the test is invalid and must be repeated. This happened to me after my 1500 in Rio and meant sitting in the doping control office for 2 hours – it’s quite common as athletes need to be hydrated to continue to perform particularly over longer events. Filling out the paperwork is also an opportunity for athletes to declare any supplements or medications they have been taking. Declaring supplements and medications is important in the case of a positive test from a contaminated substance, as it builds a strong case for an athlete’s intention to comply with the rules. Regardless, it is best practice to declare anything that isn’t food, even if it has been independently tested and sourced from a supplier like Batch Tested. Batch Tested also keeps a record of batch numbers, expiry dates and accreditation certificates for all products supplied if an athlete requires this information during the testing process.

Once declarations are complete, the last step is to sign off on the paperwork and get on with your day. Athletes are given a complete copy of the paperwork and so too is the anti-doping agency. An incomplete form is given to the testing lab with only the sample numbers and athlete supplement declarations to ensure anonymity in the testing process.


2. Were you selected for a test in Tokyo, and if so, was the process any different?

Yes, I had 1 test in Tokyo. During a ‘Village style’ competition, DCO’s typically roam around team buildings and find athletes they have on their list for the day. If they don’t get you in the village, you are pretty likely to be tested at the pool during competition if you make a final or medal. If you break a World Record you must be tested for it to be valid. The testing process is identical around the world, the only difference is when you are on team, an Australian Doctor will join you to ensure the process is adhered to properly.


3. On average, how many anti-doping tests do you complete each year? Could you estimate how many you have completed in your career so far?

Leading up to the 2016 Olympics I probably averaged 1 test every 10 days, this was easily the most frequently I was tested. Over a normal year my guess would be an average of 20-25 tests. Over my whole career the number of tests would easily be in the 100’s.


4. Did this change at all during COVID-19?

Initially when COVID-19 broke out in Australia there was probably a 6-8month period where I didn’t get tested at all, I think a lot of this was due to people not really understanding how it spread and how to best manage it. As we have learnt to live with it, tests are now conducted in a COVID-safe manner to ensure that testing can continue. Overall, it is still less frequent than pre-COVID times.


5. Do you receive any notification that you might be selected for a test?

I’ve never received a notification that I’m going to be selected for a test, apparently it is a thing that does happen occasionally, but it is rare. The only time you’ll usually find out is when you see a testing agency walk into the training pool or a late-night ring of the doorbell at home.


6. Do you need to keep Sport Integrity Australia informed of your whereabouts at all times?

Yes, I must log one hour every single day that say exactly where I will be and when with a global database. It is a global database as it is not just SIA who do the testing. In the case of FINA (the global governing swimming body) they contract global agencies who also conduct testing.

As well as one hour every day, you must also identify all regular activities eg. training times or school so if they feel like really surprising you, they can. If you are not where you said you would be during your one hour there is a strike, you only have 3 strikes over 18 months before you are handed a ban. Outside of this one hour this is more flexible. You must also declare where your overnight accommodation is 365 nights of the year, even if it is on a flight overseas. Typically, athletes set their testing hour to line up with a training time or their bedtime as these are most easy to maintain consistency in when training and minimise the risk of missing a test. They really will test you anywhere though, I’ve been tested Christmas Eve at a beach house and many years ago at school.


7. Are there any reasons why a test could be delayed?

Natural disaster maybe? Once you’ve been notified there’s nothing that can really delay a test. A test could go for an extended time if you don’t deliver a complete sample (not enough urine volume), or your specific gravity is too low (too hydrated to test) in which case you would need to wait until another sample could be delivered.


8. How long does it typically take to receive the results from your test? Does the wait time ever make you anxious, even though you are confident you haven’t consumed any banned substances?

In the anti-doping testing world, no news is good news. You’ll only be notified if your ‘B’ sample is going to be tested which would indicate that they have detected something in your ‘A’ sample. If all is clean you will never hear about it.


9. How has testing changed during your career (e.g. technology, awareness, extent of WADA list)?

To be honest I’m not that across updates in testing technology but I’m sure it is happening. Every couple of years the box or the sample collection vessel changes or manufacturing is contracted to another company – this is always ‘exciting’ as it’s something different.

The WADA list of banned substances is updated every year and comes into effect January 1st. Most of the things on there I’ve never heard of. But there is a database where you are able to search any medication or ingredients and it will tell you whether it is banned out of competition, in competition or both and provide you with a receipt of your search to keep on record. This is good practice to do with everything that isn’t food.

SIA do an excellent job in educating Australian athletes on any changes or updates to this list as well as any changes in the testing process every year with a compulsory online learning module. Many times, I’ve been overseas for a test and the DCO starts explaining something new in the process and most of the time Australian athletes are the only ones to know about it because of these compulsory

Mack Horton is an ambassador for Batch Tested – Australia’s only one-stop shop for the latest batch tested supplements and sports foods. All products have been independently verified by programs such as HASTA and Informed Sport, to show they do not contain substances that may result in a positive doping violation. Batch Tested gives athletes, sporting professionals, and nutrition-savvy consumers peace of mind knowing that the supplements and sports foods they take are clean and safe, having undergone independent, third-party testing. Visit for more information.

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