Middlesex Duathlon & Triathlon

This event is organised by Active Training World

Merchant Taylors

ActiveTrainingWorld are excited to announce the inaugural Middlesex Duathlon & Triathlon at Merchant Taylors School.

Merchant Taylors School is a stunning venue spanning across both sides of the Hertfordshire and Middlesex border and is surrounded by magnificent, picturesque grounds including the lakes, wildlife and greenery.

This is a mass-start event with a 7:15am Start. All finishing positions will be calculated based on gun time and not chip time. This is a non-draft legal race. This is not a BTF championship event. 

This event is for athletes of all abilities. 

Online entries: Pay by major credit/debit cards




We actively welcome support and involvement from local communities, businesses and individuals. If you would like to find out more about marshalling, sponsorship or group bookings please contact us at:


icon Registration

Race numbers will not be posted out in advance of the race.

Race numbers can be collected on race day after 6:00am. Registration will close before 7:15am

All competitors must comply with BTF rules - including being licensed to race.

It is recommended that you read the BTF rules and regulations, which will be applied to all races. 

All competitors must be licensed to race, so non-BTF members will be required to pay a £6 levy for a day licence. This is payable on the day at registration, (This is not included in your entry fee).

BTF members must produce their licence at registration, or a £6 levy will be charged prior to racing.

icon Event Profile

Event Name

Middlesex Duathlon & Triathlon

Event Distances

Triathlon Sprint:  750m Swim, 19K Bike, 5K Run
Triathlon Standard: 1500m Swim, 40K Bike, 10K Run

Duathlon Sprint: 5K Run, 19K Bike, 2.5K Run
Duathlon Standard: 10K Run, 40K Bike, 5K Run


Bike course: Undulating and largely rural. Run course: Flat 5km lap around the picturesque grounds and lake. Swim: Lake




Water will be provided on the course and at the end of the race




The run is traffic free but the bike is not.


Standard - 17
Sprint - 15
(on/before 31 Dec 2020)






The higher of £1 or 6% online service fee will be applied at checkout.


icon Prizes

Finishers medal for all!

Trophies for overall Male 1st, 2nd & 3rd place.

Trophies for overall Female 1st, 2nd & 3rd place.

icon Course Information

The races all start and finish on the athletics track at Merchant Taylors school. 

The run course is a flat 5km lap around the picturesque grounds and lake. The bike course is undulating and largely rural.

Standard Distance Bike Course

Sprint Distance Bike Course

5K Run Loop

icon Training Plans

ActiveTrainingWorld have free running and cycling training plans to help you train for this event:


Other Race Information

Race Numbers
Please wear your number pinned to the front of your top on the run and on the back of your top for the bike. Race belts can be used.

Parking and Transport
Free Ample Free parking is available at Merchant Taylors school. The Moor Park underground station is also within close walking distance. Please use public transport where at all possible. A location map and useful travel information is available here.

We will not be providing a changing area, therefore please come changed and ready to race. A marshalled baggage area within transition will be provided so you can keep your warm-up clothes safe during the race.

Toilets will be available.

ActiveTrainingWorld do not offer transfers or deferrals for this event or any events listed on the website. Instead every person who books an event has the option to purchase "Refund Protection" which allows them to get a full refund of entry fees in the event of an injury, illness or other reasons specified on the policy. The link to claim your refund will be on your confirmation email along with your booking reference number. Terms & Conditions are here


By entering this event you agree to the below terms and conditions

(1) I declare that I am medically fit to compete & understand that I do so entirely at my own risk.

(2) I understand that I enter the race at my own risk and that no person(s) or organisation(s) will be held responsible for any accident, injury or loss to myself, prior to, during or after the event.

(3) I understand the organisers reserve the right to alter the arrangements and conditions, should circumstances require.

(4) By entering this event, the athlete indicates acceptance of BTF rules.

(5) In the unfortunate cancellation of the event through circumstances beyond the control of the race organisers.  I understand that I will be eligible for a free place, up to the same value, in an ATW event taking place in the next 12 months.


LOCATION: Merchant Taylors' School,Sandy Lodge, Northwood, Middlesex, HA6 2HT

Location: Merchant Taylors' School, Sandy Lodge, Northwood, Hertfordshire, HA6 2HT