Review: "The Personal Trainer" by Rebecca Collomosse

The Personal Trainer by Rebecca Collomosse
Published April 2026 via Joffe Books
★★★

Juliet just wants to get in shape for her wedding—she met her fiancé in a group for widows and widowers, and it seems like her life is finally coming back together. But something about her new personal trainer, Claudia, makes her uneasy...

I picked this up for a couple of reasons. First, although I've read some psychological thrillers, it's been a while, and most of what I've read has been by big-name authors; I haven't read much in this vein from smaller presses, and I was curious. And second, I am in my Gym Rat Era 2.0; I am not interested in personal training, but it turns out that I am interested in (some) books with a character working out on the cover, even knowing that working out was probably going to be a relatively small part of it.

The earlier parts of the book I found a bit frustrating. It's clear very early on that all is not right with Claudia, and yet Juliet pretty much lets Claudia run the show—Juliet's been thinking just two or three sessions a week, but Claudia pushes for more and more sessions, and Juliet immediately capitulates; Claudia makes any number of food-shaming and body-shaming comments, and Juliet immediately withers; Claudia is suddenly everywhere, including at Juliet's house all the time, and Juliet thinks it's odd but never tries to gain any distance; Juliet's friends point out some of the ways Claudia's treatment of her is off, and Juliet weakly agrees and then continues to do everything Claudia tells her. (And—the other personal trainer—does she end up dead, or what?) Claudia gets mad throws a potentially damaging workout at her, and Juliet basically...cries and does it anyway. I understand that Juliet is insecure about the weight she's gained since her first husband died, but her doormat attitude towards Claudia feels especially odd in the context of Juliet saying that "I used to be slim and extremely fit, regularly doing 10k runs and going to the gym four or five times a week" (loc. 265*). This suggests that she has some understanding of fitness, and what is safe and is not, and hopefully of crash diets not being the way to go about things, but throughout the book she just...ignores all of this (and also ignores any suggestion that she doesn't have to lose weight and gain muscle to be lovable), and I don't know what to do with that.

There's a twist, of course—well, a couple of twists, but the book picked up for me quite a bit after the first real twist. I think by that point I was just a bit fed up with Juliet and ready for something else to happen. There aren't any huge surprises (though...I think Claudia should probably be housed somewhere for the criminally insane, probably for the rest of her life), but the last twist comes closest (and also cements Juliet as a doormat, but I guess by then we knew that). There's also a period where it genuinely isn't clear what will happen—e.g., whether all of the characters will survive—and that's always a satisfying thing in a thriller.

Overall I would have liked Juliet to be easier to root for and Claudia to not be so evil from the get-go, but it was a very fast read and an engaging introduction to this side of the genre.

*Quotes are from an ARC and may not be final.

Thanks to the author and publisher for providing a review copy through NetGalley.