IronMay Challenge FAQs

IronMay Challenge FAQ's header

Join the challenge

Complete an extreme triathlon across May, all for life-saving research.

Sign up free and you'll receive:

An Online Giving Page

A digital fundraising pack

Sign up now

Supporters raise money by challenging themselves to complete a 2.4 mile swim, 112 mile bike, and 26.2 mile run in the month of May. You can take on the challenge any way you wish: solo, as a team, all in one week or spread across the month. 

The challenge takes place 1 May to 31 May.

Once you have signed up, join the Facebook group dedicated to this challenge.

Click ‘Join Group’. Once you’re in, you can complete a form to get your t-shirt, get tips for completing the challenge, be inspired by other fundraisers and find out anything you want to know about the challenge. 

Of course! You can still set up a Cancer Research UK Giving Page using the link below and collect sponsorship for your walk that way:

There is no entry fee for this challenge.

Yes, under 18s can take part in this challenge, but we do not market to them and any third-party platform forum (e.g. a Facebook forum) is only available to over 18s. If under 18s are taking part, their parent or guardian must consent to the child’s participation, supervise the challenge and accept responsibility for complying with the challenge rules. Currently we are unable to accept registration for a child, so the child’s parent or guardian have to register on the child’s behalf. Similarly, if a child wants to raise money online and/or join a forum, the child’s parent or guardian must register for an online fundraising page and/or join the forum on the child’s behalf. 

You register as an individual but can take on the challenge as a team and split the activity up as a group or all complete a 2.4mile swim, 112mile bike, and 26.2 mile run in the month. You can also set up a Team Giving Page and invite other registrants to join via the Cancer Research UK online fundraising site. 

To set up a team: 

  • All members of your team will need to sign up to IronMay so they each have their own Online Giving Page 

  • Once everyone has signed up, log into your account 

  • Hit the 'Create new team' button and follow the instructions 

  • Once you've created your team, you can send the team page URL to friends and family so they can join too! 

IronMay is a Facebook challenge that doesn’t have an event attached to it. This challenge gives you the opportunity to complete a 2.4 mile swim, 112 mile bike and 26.2 mile run across the month of May, rather than taking on the challenge all at once in a big event. The challenge allows you to complete the distances wherever you'd like, at your own pace and in your own time. 

There are people of all levels of fitness doing this challenge. The important thing is that you’re doing something that challenges you. This will vary from person to person, so tailor the challenge however you like. It should be tough, but doable. However you chose to break down the 2.4 mile swim, 112 mile bike and 26.2 mile run, you’ll be helping us to beat cancer. 

Swimming 2.4 miles is the equivalent of swimming 160 lengths in a 25 yard pool (the average size of a pool). If you are not swimming in a location with measurable lengths, e.g. in the sea, you can track the number of miles you swim with Strava.

The only thing that matters is that you challenge yourself. Therefore, complete as much of the challenge as you can. The money that you fundraise will allow Cancer Research UK to continue to fund life-saving research and we can’t thank you enough.   

No, don’t worry, we trust you! You don’t need to provide evidence that you’ve completed the challenge to us. Updating your friends and family on your fundraising page is important though! Make sure you keep them posted on your progress and share videos and photos throughout May – the more updates the better. Supporters who regularly post their progress raise on average 40% more. 

Complete the below form to receive your free t-shirt in the post (note you will also get a Giving Page once you’ve submitted your t-shirt request). Once completed, please allow 10 working days for your t-shirt to arrive: 

If you have not received your t-shirt within this time, please contact:

Sending out your t-shirt comes at a cost to Cancer Research UK so please only order one t-shirt to ensure as much fundraising goes towards our life saving research. We ask if you do request a t-shirt that you set up a Giving Page and make a donation to your page. 

If you would like to order more t-shirts, please visit our online shop:  

Unfortunately, it costs Cancer Research UK more money to return the t-shirt. Therefore, we ask that you keep hold of it for personal use (for example bed, gym, give to a friend, etc). If you would like a replacement, please visit our online shop:  

There is not a minimum amount of fundraising that we set for participants, but we recommend that you set a reasonable target of about £150.

Setting up a Giving Page is the easiest way to raise money. You can set one up here.

It's then easy to share the page with your friends to gather sponsorship for your challenge. 

We have plenty of fundraising tools and ideas to help you raise life-saving donations. Please see our fundraising hub with everything you need from the challenge here:

As part of the automated email journey, you will receive a link to digital fundraising materials which you can download. No physical copies will be sent of any of the fundraising materials.  

You can use our sponsorship form to raise money rather than using an online method. Simply download and print off to keep track of all your sponsorship collected or pledged. Once you've completed your fundraising, please send the form with a cheque to:  

IronMay 2023, Cancer Research UK, PO BOX 1561, Oxford, OX4 9GZ 

Please note we are currently experiencing a delay in receiving and processing donations so do bear with us if it takes a little longer than usual to receive an acknowledgment.   

If you’ve decided to fundraise through your Cancer Research UK Giving Page, you won’t need to do a thing – your supporters’ donations will pay in automatically. If you’ve raised offline, simply post your sponsorship form along with your sponsorship in the form of a cheque to: IronMay 2023, Cancer Research UK, PO BOX 1561, Oxford, OX4 9GZ.

IronMay is specifically a fundraising initiative developed by Cancer Research UK, and therefore all fundraising must go direct to the charity. 

Gift Aid is a tax relief allowing UK charities to reclaim an extra 25% on every eligible donation made by a UK taxpayer. This means Cancer Research UK can claim an extra 25p for every £1 donated, without it costing you or your sponsors an extra penny. If the donation is eligible for Gift Aid, sponsors need to fill out the sponsor form, following the guidelines at the top of the page. 

Unfortunately, medals come at a huge cost to the charity so we will not be sending these out. However, we will send you a certificate in your completion email at the end of the challenge. You can also access downloadable digital badges to shout about your achievement on social. 

There are plenty of free apps that will allow you to track your miles. We recommend using Strava as you can link your Strava account to your online Giving Page. 

Find out how to connect your Giving Page to Strava here:  

There are many ways you can track how many miles you swim. We recommend using Strava so you can link your Strava account to your online Giving Page.  

If you have a tracking device that supports swimming activities: 

Connect your device to Strava – Head to Settings > Applications, Services, and Devices > Connect a new device > Follow prompted instructions 

Once connected, start recording your swim on your device 

Your swim will automatically appear logged on Strava once you’ve finished

If you don’t: 

Head to Strava 

Select the plus sign icon - On desktop this is found in the upper right-hand corner / On Android devices on the bottom right of your feed / On iOS devices in the upper left-hand corner 

Choose Manual Activity 

Fill out the form entry and save 

That is totally understandable and in the interest of safety we ask that you do not share the beginning or end of your routes – if you’d like to share then feel free to post the middle/main part of your walk.  

Strava allows you to set a privacy zone around your address to hide the start and end of your routes. In the Strava app, head to Settings > Privacy Controls > Map Visibility. For more information see: 

Please remember if posting screenshots of your walking routes and walking information into the Facebook group that your location could be visible to others in the group. Please be careful with what you are posting for safety reasons.

We recommend: 

A well-maintained road bike that you feel comfortable on 

Lights and high-visibility clothing (if exercising in the evening) 

Protection from the elements – layers of clothing, waterproofs and sports glasses 

Swimsuit/ swim shorts 

Running trainers 


Swimming cap 


Water bottle 

Yes! We have cycling jerseys, swimming caps and running tops available on the CRUK shop for supporters and participants of this challenge to purchase. 

Our CRUK cycling jerseys are £29.99 and can be found here: 

Our CRUK swimming caps are £7.00 and can be found here:  

Our CRUK technical running t-shirts are £15.99 and can be found here: 

You are welcome to complete the challenge wherever is convenient for you. Indoor leisure centres, outdoor lidos, lakes, lochs, the sea, or any stretch of safe water, are good locations to complete the ‘swim leg’ of the challenge. 

If you are open water swimming, please follow the following guidelines:

If you are swimming in open water, never undertake this challenge alone. Please enjoy this challenge with others who can assist you should it be required. Always be aware of your location and take your mobile phone to wherever you are swimming. 

If you are considering attempting this challenge outside in open water, please check the weather forecast, tides and water conditions in advance and plan accordingly. Ensure you know the conditions and how to protect yourself and do not partake if you do not feel fully confident. 

Always ensure you have taken a means of calling for help in case of emergency for you or someone you are with. 

Check local advice and choose your locations carefully. Seek out locations which are familiar to you and ideally with local lifeguards. Ensure it is safe for you to get in the water, and you can exit easily. 

This challenge is entirely at your own risk, so please assess your ability and safety before you participate. Cancer Research UK shall not be liable for any injury, damage or loss to you or your property that might occur as a result of your participation. 

If you have underlying health conditions (i.e., heart disease, asthma, lung conditions) or any other medical conditions that might be affected by exposure to cold water, or if you are pregnant, then please seek appropriate medical advice before proceeding. 

Do not take part in the challenge under the influence of drugs or alcohol. 

Plan your outdoor swims in daylight hours and avoid dipping in the dark. 

Approach the challenge sensibly and don’t go beyond your capability levels to participate in the challenge. 

If you are swimming in open water, it’s advised that you wear brightly coloured clothes, and your Cancer Research UK swim cap so you can be easily spotted. It will also help you retain body heat while in the water. We have a CRUK swimming cap available to buy here, to make sure you can be spotted easily. 

If taking part in open water, you may also like to wear a wetsuit, which would aid buoyancy and make you feel more comfortable in the water. Neoprene boots and gloves are also a good addition to ensure your hands and feet do not get too cold.   

Always enter the water slowly and avoid jumping in as this could cause cold water shock. 

Seek help immediately if you feel very cold, woozy, nauseous, disorientated, dizzy or faint. 

In case of open water emergency, call 999 for help and ask for a coast guard.

Warm up gradually after getting out of the water, dry yourself off and put on warm, dry layers.  

Avoid standing around. Have a warm drink and some food, and move to a warm location, especially if you’re swimming outside 

We recommend reading the following guidance too: 

If you are swimming indoors, please follow the following guidelines:

If swimming indoors, such as at a local swimming bath, please observe their rules. These normally entail things like no running around the pool, no diving unless specified, no swimming after consuming alcohol, checking depth and length to ensure you are confident with it, etc. Ask a member of staff for guidance if you’re unsure. 

This challenge is entirely at your own risk, so please assess your ability and safety before you participate. Cancer Research UK shall not be liable for any injury, damage or loss to you or your property that might occur as a result of your participation. 

If you have underlying health conditions (e.g., heart disease, asthma, lung conditions) or any other medical conditions that might be affected by this challenge, or if you are pregnant, then please seek appropriate medical advice before proceeding. 

Do not take part in the challenge under the influence of drugs or alcohol. 

There are many hazards to swimming in a reservoir. Therefore, we advise against using them. 

Reservoirs can be deceptively deep with unexpected drops which aren’t visible from outside of the water 

Reservoirs are often in isolated places, making it difficult to receive immediate help 

Hidden pipes and machinery can be hazardous 

The sides can be steep and difficult to get out from 

There may be hidden obstacles, rubbish, broken glass, etc that people have discarded, and may cause injury 

The temperature tends to be very low 

Of course you can! Some top tips for exercising on a hot day include: 

Wear a damp, cool bandana 

Hydrate before, during, and after exercise 

Try to exercise in the cooler parts of the day and in shade where possible 

Light coloured clothes will reflect the sun’s rays

Avoid tight clothes, and switch to thinner socks 

A breathable cap keeps sun from your scalp, and sunscreen is important for your skin in the hot weather

If you’re sensitive to insect bites, then make sure to use some insect repellent! 

Remember to listen to your body and don’t push yourself if you’re feeling fatigued, dizzy, etc. Stop for rests and if urgent, seek medical attention. For more information see this guide: 

If you’re unsure about whether the weather will cause sunburn/skin damage, please check the UV forecast here: 

If you're exercising outside, use plenty of sunscreen with SPF 15+ with a 4 or 5 * rating which will sufficiently protect your skin (and apply everywhere, not just exposed skin!) Remember to also apply regularly throughout and after.

You can find further information via the CRUK website at:

It’s not unusual to encounter bad weather when exercising in the UK. It’s important that you have the right equipment and top tips if you’re exercising in adverse weather. Alternatively, it’s more than ok for you to complete the challenge inside at a gym or in your home, if those are options for you. 

When cycling and/or running in adverse weather, remember to check your route and know your trail. Understanding your surroundings will help you avoid difficult terrain and ensure you stick to safer, flat surfaces. When swimming in open stretches of water, remember to check the water temperature and any tides and currents that are or could become present before you enter the water.