If the idea of an outdoor swim, a bike ride and long run sounds a bit unappealing in our bleak mid-winter, then fear not. You can choose to take part in Tri January and stay warm indoors.
You don't even need to worry about the long distance element. As a pure entry level sampler for newbies, the flexible programme means you can do a few minutes in a pool or on a rowing machine, spin bike, and treadmill.
You don't even have to do all three one after the other, but can space out your events at a time that suits you.
Steph Makuvise, participation officer at Welsh Triathlon, says: "Tri January is part of the wider campaign of Go Tri. It's aimed at getting more people from the wider community involved in the sport.
"It's a fun introduction to the sport - shorter distances, more accessibility - an entry level offer, if you like, the Park Run of Triathlon.
"People may think, it's freezing, why would you want to do triathlon? But Go Tri is quite adaptable. It doesn't have to follow the swim, bike, run, routine of traditional triathlon.
"People can do indoor triathlons using gym equipment. So, it might be row a certain distance, run a distance, and bike a distance. It's not about how you do against others, it's about how you do as an individual and improve yourself."
Tri January offers three elements. There is the basic gym introduction where someone can try different distances and log their times online, check on their progress through the month, and compare their times to others if they want a competitive element.
There are also beginner sessions for existing triathlon clubs to attract new members.
And if a new triathlete really gets the bug, then some clubs are offering events for new triathletes to dip their toes into the joys of competition.
But mostly, it's about having fun and gaining the benefits of regular exercise.
As befits one of the UK's fastest growing sports, Go Tri in Wales has gone from a handful events in 2017 to 35 this year and January 2020 will be the second year of Tri January.
Around 1,500 people in Wales are currently registered with profiles on the Go Tri programme which carries an impressive 53 per cent level of female participation.
The triathlon club scene in Wales has also grown rapidly in the Brownlee brothers era and the world class Welsh success of triathletes such as Non Stanford, Helen Jenkins and Liam Lloyd.
There are currently 90 registered triathlon clubs in Wales and Gareth Evans, national events officer for Welsh Triathlon, says: "Triathlon is an individual sport, but so much benefit comes from being a member of a club. It provides coaching support, social support, as well as the competitive element from each club.
"We are trying to look at Wales as a broader sporting nation and trying to emulate the club rivalries in other sports and bring that into triathlon.
"Clubs are growing rapidly. Caerphilly Tri-ers triathlon club won a category competition at Ironman Wales last year and have grown from 20 members to over 120 in 12 months."
For those thinking of taking the plunge for the first time in January, though, you won't even need a wet suit.
As Steph Makuvise says: "You don't need fancy bikes and wet suits and special gear for Go Tri. You could turn up with a BMX, a pair of Converse, and a T-shirt and crack on and get involved. It is that accessible."
For details about Go Tri and Tri January, go to the Go Tri website, run by British Triathlon. https://www.gotri.org/