Usually the dawn of a new year prompts many people to adopt a healthier lifestyle.
Maybe it's losing weight or taking on 'Dry January'.
It could be walking more, or signing up for that gym membership you've been putting off for months.
But for one Co Antrim fitness coach, he has decided to swap his clean-living lifestyle for 30 days of processed foods, refined sugar, caffeine, takeaways and alcohol.
Newtownabbey man Gareth Edgar started off his challenge on January 1, and so far he says the results have been "eye opening".
He added: "My energy levels are constantly up and down, and I am sleeping during the day now which I would never do.
"I am taking in more sugar and caffeine, so I am constantly needing a pick-me-up. Instead of consistency with my energy, I have inconsistency. I am buzzing, then dropping, buzzing, then dropping.
"That's what happens when you don't have structure and consistency, and a good baseline of food.
"But it is giving me an insight into the way many people feel when they start off working with me. I now know why they are lacking energy, feeling stressed or anxious, and why some feel depressed.
"I now understand why people go through this cycle, and if I can help one person break that cycle and come out of that, then this will be 30 days well spent.
"I just want to learn as much as I can."
A former Irish League footballer, Gareth - who turns 34 on Friday - was forced to retire early through injury and immersed himself in education to become a prominent health and lifestyle coach.
Some of his clients have included Ulster Rugby, the Belfast Giants, boxer Steven Ward and motorcycle racers Glenn Irwin and Alastair Seeley.
His life has always been structured, especially when it comes to nutrition and training.
So why take this challenge on?
"I have been in this industry for over 14 years. I have a background of playing Irish League football but had a bad injury. So I took myself back into education and I always loved training," he explained.
"I have never been out of shape and I have always looked after my nutrition since I was a kid. I would have preferred fruit and veg over sweet stuff, and I would have had diluted juice instead of Coke. I just went towards what you call 'healthy' foods.
"I get a lot of clients coming to me face-to-face and also online who are low on energy, depressed, anxious, have mental health issues, constantly fighting with their weight and struggling to stay motivated.
"These are all things I have never really struggled with. I have always been very disciplined and structured. I wouldn't call it regimented. I do love a takeaway, and I would enjoy a beer with my mates. But I would always have structure.
"So when it comes to nutrition and training, I know psychologically and physiologically what happens. But I have never felt that. I have never felt being out of shape, or being lethargic due to how poor my diet is or how reduced my activity levels have been.
"I wanted to experience it first hand, to basically create a deeper understanding of it. Get down to the emotional side of it and know what people are going through."
Gareth added: "My wife was very sceptical of me doing it, but I wanted to throw myself in at the deep end. I am doing it for 30 days which is only a small glimpse, but it will give me better clarity and understanding.
"I am always thinking of how I can help the people I work with. What information can I give them? And what information can I give them so they don't feel the way they do.
"How can I give them better training protocols and nutrition advice, and things that can be realistic? You can go on Google now and type in 'how can I lose weight?'. And you will get advice to help you lose weight.
"But I want people to do it in tandem with their own lifestyle, not with the way I live. That won't happen.
"And I certainly don't want to live how someone else lives.
"So I need to tweak their lifestyles so they have more energy and feel better in themselves. Have more motivation so they look after themselves more.
"When you help people change, they start to feel better about themselves. People want to lose weight, and when you break it down they want to feel better.
"They want to look good, and that could be naked in front of their partner. It comes down to 'feel'.
"So I want to feel how s*** it is eating a bad diet and not training as much. I knew how this challenge would make me feel, and how it would change my body. But for me it is more about the emotional side, and how I 'feel'.
"I want to understand how the people I work with feel. A little deeper understanding."
Gareth abides by the mantra, 'be your own scientist', a phrase he regularly shares with clients.
It involves getting them to evaluate what works best for them, and what doesn't.
"I call this a challenge, but I am my own scientist and I want to learn," he added.
"This is more subjective. I obviously weigh myself, and I know I will put on weight. But for me it is more about the psychological side of things.
"I want to know mentally what will happen to me. So I am living in the life of my members for 30 days, and there seems to be a lot of interest in it."
Gareth's normal routine would involve early starts and a consistent sleep pattern, and a daily calorie intake of approximately 3,300 calories made up of 'real' foods.
He would have six meals a day, interspersed between working with clients and his own training regime which can sometimes include two sessions a day.
For the 30-day challenge he took data from his clients to work out a new nutrition and training plan, taking into account what they would normally have consumed on a daily basis.
He also introduced alcohol and caffeine to his weekly routine, as well as regular takeaways.
"I started on January 1, and halfway through I have noticed a big difference," he said.
"When I take someone on board, I get them to map out their lifestyle. I get to give me a seven-day plan of what they're eating. I get them to record how much sleep they have, look at their mood and correlate that with their nutrition.
"So I basically get a snapshot of how they live, and I have used an average of that data to work off for this 30-day challenge.
"On average they were training twice a week before they came to see me. They were drinking between 5-7 pints of beer a week, and their average sleep was six hours.
"A lot of them were feeling down about themselves, had a lack of motivation and there was a lot of anxiety, which is quite common.
"So I took all their data, and I am even eating the foods they were eating. It has been a big eye-opener.
"The nutrition would be a lot of processed foods, high sugar, simple carbs, poor protein choices. Their pick-me-ups are coffee and sugar. That gets them through the day.
"And if they make it through the week their 'pat on the back' is getting drunk, and some of them drink during the week.
"I don't really drink, and I hadn't drank for a year previous to this. Alcohol is a nightmare for me in this challenge."
Gareth also admitted restricted exercise had proved the biggest hurdle in his challenge.
"The toughest part has been a lack of training," he said.
"My training helps me blow out steam. I usually train six to eight times a week, but I am now down to twice a week. And that's the two online classes I do for my clients.
"One is mobility, and one is an intensity class. I did the intensity class the other day, and after the first set my quads started to cramp.
"I have done marathons and endurance events, and I have never felt like that. I felt pathetic in the video."
While Gareth admits the lifestyle change has been an "eye opener", he believes the 30 days after will be a bigger challenge when he ditches processed foods, sugar and caffeine.
"I think the 30 days will be interesting, but the 30 days after will be even more interesting. When I return to clean eating and training more," he said.
"It will be tough going through that detoxing process, but I think this is a worthwhile challenge that will give me a better understanding of what my clients are going through.
"And if I can help them then it's worth it."
Anyone wanting to follow Gareth Edgar's 30-Day Challenge should check out his Instagram page.
