The Crash Diet of Exercise

Why the insanity workout is insane!

For those of you who prefer home workouts rather than the gym, programmes like insanity may seem like a good option. The adverts sure are persuasive; '1 year of fat loss in 60 days' 'burn 1000 calories an hour', who wouldn't want that? However when you analyse the programme for the person they are marketing to (a person out of shape, not used to exercise, looking for a quick fix), it is dangerous and highly likely to cause injury, as well as being unsustainable! These extreme conditioning programmes are the exercise equivalent of a crash diet.

Session structure

The insanity workout is a 60 day programme with 6 sessions a week. Within the 60 days there is a week of lower intensity then it's back to high intensity for the remaining sessions. I've mapped it out as you would a typical coaching programme with the 'hot sessions' in red:

You would normally have 1-2 high intensity sessions in a week to make sure it's sustainable and they are performed well.

Each session is an hour of 3mins on 30s off. This work to rest ratio of 10:1 is not supported in research or when you consider the physiology of how long your body needs to recover in order to execute exercise effectively.

Does it work?

Like crash diets that go extreme, an extreme conditioning programme like insanity will work at getting your fat down and fitness up. Despite having a poorly reasoned work to rest ratio, it is still high intensity training (HIT) and there is very good evidence that HIT training decreases fat and increases fitness.

However it doesn't necessarily improve your strength. It is body weight exercise only i.e. jumping jacks, burpees, squats but because it's high reps low weight it will only be targeting muscle endurance. The overload needed to get strength gains will not be there with body weight alone. Therefore, you will not be able to squat more weight but you will be able to do more air squats and press ups.

Typically for strength training you need a rep range of 4-6 at 80% of your maximum with a recovery time of 2-3mins to allow maximum muscle recruitment. In insanity the workouts are 30-60s with reps generally over 20 which targets endurance.

The workouts are much more cardio orientated than strength.

What are the issues?

It's unsustainable

Working out 6x per week at max intensity is not sustainable. Whilst they acknowledge this is only for 60 days that is still a long time to sustain this level of work if you are not trained for it.

It has been seen in soldiers who undertake these extreme conditioning programmes to supplement their training become ‘catabolic nightmares’, where their bodies go into shut down as the workload is too much. It is recommended that interval training is used sparingly in a workout plan due to the demands on the body.

It goes against research

Not only does it have none of it’s own research, it goes against research and guidelines. There is not even physiological theory to support it. Interval sessions that have been proved to work in research have work to rest ratios of 2:1, 1:1, 1:2 (insanity is 10:1). If you have insufficient rest, your lactate levels build up and your muscles will stop being able to work effectively. You actually see this on the videos of the participants in the background needing to pull up or start losing form. As well as being bad practice, it is actually inefficient and unnecessary to work that hard for that long.

It's unsafe

I have seen many patients with injuries after trying this programme. It is often musculoskeletal injury due to overload or fatigue affecting movement control

If stress persists for an extended time the exhaustion phase is reached = fatigue/soreness/inability to adapt to stressors/overtraining/maladaptiveness if no variety or stress too great.

Their marketing is misleading

Nowhere in the 30min infomercial does it say not for beginners in fact it specifically says ‘you do not have to be in shape to try it’. There is a disclaimer at the bottom of the info pack that says this is not a programme for beginners but you have to search for it and the way it is marketed does not imply this is a problem.


If you want to do the insanity workout or equivalent, I would make sure you are happy running for 30-60mins first and can do 10-20 push ups.

Add in more rest days - you SHOULD NOT be working to max intensity 6x per week. Unless you are very used to this type of training I would add in extra rest days or do something low intensity on the off days.


Extreme conditioning programmes like insanity are not for the faint hearted. There is a place for this type of work but not in the way they prescribe it which can leave you open to injury and doing unnecessary work. As with crash diets they are unsustainable and can leave you worse off once the initial phase is over. There are no quick fixes, if something seems to good to be true - it probably is.


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