The owner of a chain of gyms has spoken out against Ivanka Trump, after the first daughter used an alias to sign up for one of her classes.

In a recent Facebook post, Solidcore gym founder Anne Mahlum wrote that she recently found out Trump took one of her $37 classes.

After learning that, she says she reached out to Trump's camp - apparently to lobby her.

Ivanka Trump, rear, and her husband Jared Kushner step off of Air Force One with their children as they arrive in West Palm Beac

Anne Mahlum (left), the owner of gym chain Solidcore, wrote about first daughter Ivanka Trump (right, at the White House on Friday) taking one of her classes

Mahlum said that she reached out to schedule a meeting with Ivanka after learning that she signed up for one of her classes using an alias

'What you do when you find out Ivanka Trump just took [solidcore], but used an alias to sign up for class? You reach out and ask for a meeting.

'While I don't know her and I always seek to understand...I do know her father is threatening the rights of many of my beloved clients and coaches and as a business owner, I take my responsibility to protect and fight for my people very seriously,' Mahlum wrote.

The classes are described as high-intensity, full body, low-impact 50-minute session on a resistance machine with no more than 12 people per class.

In a later statement to media outlets, Mahlum she is 'extremely proud of the inclusive community' at her gyms and that it's her 'key priority to protect that community'.

Solidcore is actually a favorite of former first lady Michelle Obama, who now lives in the same neighborhood as Ivanka

'As I said in my Facebook post, I do not know Ivanka, but I welcome the opportunity to open up the communication channels, and I hope she takes me up on the offer,' she added.

Mahlum faced backlash on Twitter from Trump supporters who believed Mahlum overstepped by reaching out to the first daughter.

'Ivanka Trump can't even exercise without being harassed! D.C. gym [solidcore] must be boycotted!' one user wrote.

Ivanka has not responded to Mahlum's post online.

Many Twitter users were outraged that Mahlum would publicly attack Ivanka

The first daughter was busy at the White House on Friday, helping her father welcome the Japanese Prime Minister.

It has been a tough week for Ivanka, who saw Nordstrom officially drop her line due to poor sales. Other stores including Neiman Marcus, TJ Maxx and Marshalls followed suit.

Trump critics have been boycotting the line ever since the election.

Solidcore is actually a favorite of first lady Michelle Obama. The former first lady now lives in the same neighborhood. Two Solidcore locations are just blocks from the area.

In addition to 13 DC-area locations, the chain also has branches in Georgia, Pennsylvania, North Dakota and Minnesota.

Mahlum raised between $1 to $2million last year, to open about 50 more studios.

According to the gym's website, the workout the class is a 'high-intensity, low-impact, 50-minute session that is done as slow as possible to lengthen and tone your body'.