Fitness, Weight Loss

75 Hard: what you need to know before taking on this viral fitness challenge


Juliette Stebbings, University of Portsmouth and Robert Rowland, University of Portsmouth

Every week there seems to be a new fitness challenge trending online. But one that’s managed to remain popular over the last couple of years is the 75 Hard Challenge. On TikTok alone, the hashtag #75Hard has more than 1.2 billion views.

It’s easy to see why this particular challenge has remained so popular, with video after video of people showing off their staggering body transformations – which they claim are the result of the challenge.

The 75 Hard challenge is not for the faint of heart. In short, it involves doing each of the following daily for 75 days:

  • Two 45-minute workouts
  • Following a diet (whatever diet you choose)
  • Reading ten pages of a non-fiction book
  • Drinking 4.5 litres of water

The creator of this challenge claims that completing it will allow you to change your life forever and lead to career success, greater confidence and better relationships alongside being physically fit. There’s currently no scientific evidence to support these claims.

Although the requirements of the 75 Hard challenge are pretty outlandish by most people’s standards, seeing the transformations and online testimonials of how the challenge changed lives may explain why many continue to be curious about it.

Here’s what to know if you’re thinking about giving it a try.

Is it safe?

The two main components of the 75 Hard challenge (eating right and exercising regularly) are of course good for your health. Plenty of research shows that proper diet and regular exercise lowers the risk of obesity and can prevent chronic and age-related diseases, including some cancers and cardiovascular disease.

But in order for diet and exercise to be effective, they must be done in a safe way.

When exploring the safety (and injury risk) of exercise, one of the most important considerations is physical load. This is the combination of how much, how hard, and how often you exercise.

If you have a high physical load (such as exercising intensely seven days a week), you are more likely to suffer from injuries, illness or other issues – such as overtraining syndrome. Overtraining syndrome typically happens when you train too much and and recover too little between exercise. It can lead to fatigue, which may also increase risk of injury.


Previous injuries, age, and even weight can also further increase your risk of injury. These factors will also determine whether or not you can tolerate a high training load.

For most people, training twice a day for 75 days is likely to be too much for them. To reduce the risk of injury it’s widely recommended to split training sessions up and schedule in rest and recovery days.

Not recovering properly or giving yourself rest days may also affect your fitness – and may actually make it harder to see the results you might be hoping to see when following the 75 Hard challenge.

Diet and sleep also have a large effect on your ability to recover well and fuel exercise. But everyone’s needs are different, so it’s important to listen to your body. Many generic diets won’t work for everyone, so adapt the diet you follow as necessary.

Is it life changing?

From a psychological perspective, we can also recognise the potential positive impact of fitness challenges such as 75 Hard on wellbeing, self-esteem and mental health.

But a person’s success in completing a challenge like 75 Hard may be underpinned by the type of motivation they have for doing so. According to the “self-determination theory”, every person has a different type of motivation for doing something.

These range from more beneficial to less beneficial types. It’s not simply about how much motivation a person has for an activity, but what the quality of that motivation is like.

Beneficial, or quality, types of motivation describe people who do an activity for an intrinsic (internal) reason. For example, they do it because they enjoy exercise or they want to learn new ways of feeling healthy.

Less beneficial types of motivation are when a person does something because of an extrinsic (external) reason. Examples of external reasons include feelings of guilt or shame (such as coercion from others or feeling bad about the way they look), or to receive external rewards such as money or recognition.

If a person has enough of either type of motivation, it’s probably the motivation needed to get them through the challenge. But the more important issue is whether or not the person maintains the healthy behaviour after finishing the challenge.


This article is part of Quarter Life, a series about issues affecting those of us in our twenties and thirties. From the challenges of beginning a career and taking care of our mental health, to the excitement of starting a family, adopting a pet or just making friends as an adult. The articles in this series explore the questions and bring answers as we navigate this turbulent period of life.

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Beginning any diet or exercise programme is difficult. New exercisers often hold unrealistic expectations of what they can achieve, which can lead them to have trouble prioritising and scheduling exercise. Maintaining lifestyle changes can also be challenging.

Extrinsic reasons for doing something often lead to dropout. Yet when a person does something for intrinsic reasons, they are more likely to stick with it and can maintain the positive outcomes – such as physical fitness and weight loss. This may be even more likely if a person has access to ongoing support following a structured exercise program.

For some people, the 75 Hard challenge may kickstart them into improving their fitness and lifestyle. But being able to maintain that level of activity may depend heavily on the reasons why they are doing it. The rigid list of tasks and consecutive daily nature of the programme may also may it difficult (and even dangerous) to complete.

Anyone contemplating the 75 Hard challenge should seek advice from their healthcare provider or a fitness trainer, and perhaps consider adapting the tasks to suit their fitness level or personal goals.


Juliette Stebbings, Senior Lecturer in Sport, Exercise and Health Psychology, University of Portsmouth and Robert Rowland, Senior Teaching Fellow in Strength and Conditioning, University of Portsmouth


This article is republished from The Conversation under a Creative Commons license.
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