She writes on Reddit that after 'slow' progress for 20 months, she now sees an improvement in her mood and her body

A young woman on Reddit has shared a set of inspiring before and after images, which showcase how an exercise plan she began 20 months ago in an effort to lessen her depression has not only helped her mentally – but has also ensured a dramatic physical transformation.

Aliesha Peterson, 22, detailed the extensive fitness routine that helped her go from 145lbs to 127lbs – and enabled the Alberta, Canada, resident to gain a noticeably fitter, and much more muscular, physique, as well as an impressive six-pack.

'I can honestly say I am sooo thankful I started taking better care of myself [sic],' she wrote under her Reddit name ahhhgodzilla. 'My progress has been fairly slow but, to me, the most important thing is that I didn't give up.'

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Impressive results: Aliesha Peterson, 22, first started exercising in August 2013, left; as of April 2015, right, she has lost nearly 20lbs and gained a six-pack

Aliesha wasn't always a fan of working out - and explained that she didn't start hitting the gym to look better in a bikini, either.

'I was extremely depressed and refusing to go back on anti-depressants,' she explained. 'I went and saw a therapist, and she recommended that I join a gym and start working out three times a week.

'I reluctantly obliged and to be completely honest, I absolutely hated it. 'I hated how uncomfortable I felt there, that I obviously had no idea what I was doing.'

But after three months of sticking with it, she admitted that she started to 'somewhat enjoy it'.

Aliesha's routine is made up of exercises that focus on a different part of her body for each day of the week, and she will often do cardio on the weekends. Her workouts include several sets of squats, bench presses, crunches, curls, and planks.

On Wednesdays, she works on her back, which she said is her favorite part of her body. Her back exercises include deadlifts, hyperextensions, and chin ups.

Bringing sexy back: The 22-year-old says her back is her favorite part of her body, and she focuses on exercises to strengthen it every Wednesday

'Before' body: Aliesha, pictured here in 2013 before she started exercising, was by no means overweight, but she has since become more toned by sticking to a demanding workout schedule

After about six months, Aliesha started changing her eating habits, too. While she once stuck to an unhealthy diet which included fast food 'at least twice a day', she began cooking her own meals and choosing to eat healthy food.

Now, her diet consists of eggs, yogurt, fruit, chicken, seeds and nuts, green smoothies made with vegetables, protein shakes, turkey, and salmon.

Aliesha admits that her story isn't one of shocking rapid weight loss - but she says her slow progress is the reason she's been so successful.

'I'm sure if I completely changed my lifestyle all at once that my results would have been a lot more impressive in a much shorter amount of time, but it would not have been sustainable,' she wrote.

Because she's worked at a slow, steady pace, she's been able to maintain her new figure - which has been a boon to her self-esteem.

'I am much more confident in my body,' she told Daily Mail Online. 'I no longer hate looking in the mirror and have learned to accept my flaws and am able to see the positive qualities I possess as well.'

Barely-there biceps: In October 2013, pictured, Aliesha had only just started going to the gym to help her improve her depression

Welcome to the gun show: Pictured this month, Aliesha's arms have grown much more muscular; she says she now loves going to the gym

Of course, Aliesha added, it isn't always easy to maintain the motivation to work out five to seven days a week, but sticking to a routine has helped.

'I truly believe the key to bettering yourself is to cultivate and preserve healthy habits,' she continued. 'The first few months are the hardest, but once you make it through that stage it becomes a lot less painful, and you may even learn to enjoy it like I have.'

She is also enjoying what working out has done for her mental health.

'While I still struggle with depression, it is much, much less severe,' she said. 'Instead of laying in bed all day crying, letting it consume me, I get up and do things - go to the gym, do yoga, walk my dogs, see friends.