TikTok's latest wellness trend sees Brits 'locked in' for maximum self-improvement

The Great Lock in of 2025 is a recent trend that has invigorated thousands across social media as many pledged to “lock in” and commit themselves to pursuing their own academic, career or fitness goals in the run up to 2026.

Ranging from September 1st to December 31st, the self improvement trend – started on TikTok – has urged viewers to strive to hit whatever personal goals or targets they might have before the year comes to a close. Unlike other social media self-improvement trends, The Great Lock in of 2025 does not follow a strict training plan or dietary requirement but is more of an individual pledge of self-improvement.

The term “locking in” – which the trend is named after – is slang for focusing intensely on a task, goal, or activity,shutting out distractions and committing fully to it. The phrase often being associated with gaming, sports, or personal pursuits like self-improvement.

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The trend doesn’t contain any unrealistic bench marks such as "go to the gym X number of times every weeks” or "lose X amount of weight". The Great Lock In is more of a rallying call for many across social media and those striving to hit whatever goals they might have before the year ends.

Some have claimed the The Great Lock In is just a rebranding of another self-improvement nicknamed"The Winter Arc" which did the rounds on social media last year.

Others have asked why there is a need for this “The Great Lock in of 2025” movement and joked the self improvement trend is redundant, claiming: "We never locked out."

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On the search for how people could really "lock in" throughout the last quarter of the year, the Mirror turned to the expertise of Dr Tobias Kohler, the head of the men's health program at Mayo Clinic in Rochester, Minnesota. Dr Kohler– who has over 100 hours of wellness coaching under his belt – revealed four vital things people to do to make sure men’s testosterone levels stay high and our body’s hormone levels operate at their ideal levels.

Minimise Stress

The first area the doctor urged people to improve upon to ensure their bodies are operating ideally was minimising stress. The doctor explained when a person is faced with too much stress their body is thrown into a "fight or flight mode".

Dr Kohler explained stress like this: "It's like fight or flight. It's take its energy reserves and shunt it towards something that maybe it doesn't value as much sexual health and muscle growth. It want to shunt the resources towards protecting your brain and heart and just keeping you alive."

"So when you have high stress in your life, you have high cortisol, your body has a choice. And if you let that stress get too high, the body's going to deemphasize the fun stuff and it's going to support stuff that'll keep you alive." The doctor added for men "minimizing stress is a very important way to raise your testosterone levels naturally".

Better Sleep Hygiene

The second lifestyle amendment the doctor said was foundational to stay healthier was to have better sleep hygiene. Dr Kohler said: "The most efficient way to sabotage testosterone production and muscle growth, it's don't sleep.

"People who sleep poorly die young. We know that the vast majority of the important hormones for muscle growth and getting jacked and staying trim [in-shape] are produced during not only sleep but REM sleep.

He added: "If you have depression or anxiety and you do a sleep study it's always going to look weirder than it would for a normal person. So again it tells you sleep is vitally important.

Avoid Bad Habits

The doctor also warned against over-inducing harmful habits which can cause unhealthy lifestyle choices and in extension adversely affects other areas of life such as your sleep schedule.

Kohler warned REM sleep – crucial for memory, learning, and overall brain function and development – can be affected from indulgence in certain substances. The doctor explained: "When we talk about habits, alcohol cannabis are really effective in disturbing specifically REM sleep."

Kohler warned the best way a man could destroy testosterone levels was if they frequently had one to two drinks before they went to bed every night.

Last but not least, Kohler asserts an effective nutrition rich diet was essential for a people’s body to stay healthy and operate correctly. The doctor explained there were numerous diets people could try but it is imperative people find the correct diet that works for them.

Despite this the doctor stressed proper protein intake was essential for a healthy diet regardless of whatever diet you pick. He added: "You probably should have a protein forward, protein centric diet. So every meal should probably have more protein than you think. I think a reasonable goal for all humans is 100 grams of protein per day.

"If you're really trying to get muscular and strong the evidence says somewhere around a gram of protein per pound of ideal body weight." Kohler added: "This takes a very conscientious strategized approach to make this happen. It's very tough to do unless you're really focusing on it. But protein has a lot of benefits."

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