Even the most dedicated of gym-goers have to skip a workout from time to time.
Whether something cropped up, or you just can't face a gruelling session, even the best of intentions sometimes go amiss.
But one woman has been left irritated by her gym' s "snotty" response after she had to skip a couple of classes at the "last minute".
And she feels it is unfair for the gym to send "an email threatening to 'black list" her from classes following the absences.
The problem came to light when the frustrated woman took to Mumsnet to blast her gym and share her side of the story.
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Her post began: "The gym I go to is a relatively cheap 24-hour one, although not one of the big, well-known companies.
"They repeatedly cancel classes at short notice and you can only book a class a few days before. On three occasions I have been unable to attend a class last minute and have received a snotty email from them about this."
It continued: "Don't get me wrong, I'm fully aware most gyms employ this tactic to guilt you into cancelling your space ahead of time and prevent you from taking a space someone else might have wanted.
"I think it's 100% fair to send an email if the class was fully booked with a waiting list and you've not turned up."
But the mum said she did not feel the response was fair given the circumstances.
"This gym shows how many spaces are available in the class until the class begins" and "there have always been spaces," she explained. "A snotty email isn't really appropriate as I haven't actually taken a space away from someone else?"
She added: "Equally, there is no polite cancellation email apologising when they cancel classes (quite regularly) however they're quick to send the email when you don't attend."
The mum concluded by asking if she was being unreasonable to be irritated by the "black list" threat.
Replying to comments, she also clarified: "On the three times I couldn't go it was within 30 mins of the class starting so I couldn't cancel; it's all done on an app which blocks your ability to cancel the class after a certain time.
"When I've not turned up it has been when I've genuinely intended to go but last minute been unable (i.e due to children or childcare issue rather than 'can't be bothered')."
Despite her reasoning, several Mumsnet users suggested it was not the gym but the mum who was acting unreasonably.
"It’s fair enough - just cancel your class. The staff don’t know that you only didn’t cancel because X, Y or Z. It’s a fair system. If you only knew 30 minutes in advance that you couldn’t go then when the email comes through just suck it up," wrote one person.
A second said: "They're just standard automated emails - there's really no reason to be irritated."
But many others also expressed sympathy for her situation.
"People have to cancel at short notice, that's life," wrote one commenter, who said the mum was not being unreasonable.
"I can see the logic in it, it's just a real pain when things happen last minute," another added.
Do you agree? Let us know in the comments below.