IN Without Apology, Leah Hager Cohen addresses the subject of female aggression. "Any girl who boxes challenges the idea of what it means to be a girl in our culture. Through the prism of what she does with her fists, she sheds a fiercely contrarian light on our most fundamental notions about femininity and power and appetite and shame and desire."

If you like your writing to verge on the pretentious, then Without Apology might be the book for you. The kernel of Cohen's book is a year in the life of Somerville Boxing Club, in a working class area near Boston, and four young female boxers and their trainer. Her original visit was meant to be a one-off but she kept going back to the gym to watch the girls train.

Women's boxing is something of a taboo. The first bout Cohen witnesses is jeered before the women silence the crowd with their performance. Girls are not expected to fight and the four teenage girls are oddly incongruous to the gym. Cohen is surprised to find herself envious of the freedom they enjoy sparring and this leads her to ask their coach to join in with the training.

However, Cohen never really shakes off her antipathy towards the sport. To her, everyone who makes it to the gym is in some way broken inside. There is some flaw with the people themselves for boxing in the first place, although she does include herself amongst their number. It is unclear whether she thinks this pursuit fulfils some need these people have or whether it is an expression of their problem.

It is true that boxing has traditionally flourished in tough, downtrodden areas. It is celebrated as a route out of poverty. The young girls are growing up and in the narrative they are constantly threatened by their surrounding neighbourhood. The threats are vague, taunts from men which the author does not witness herself, but they are universal and this is how Cohen understands the girls' willingness to box. They are toughening themselves up to take on the world outside. The girls' coach, Raphi, presents evidence against the argument that Cohen is taking; she did not grow up in poverty or amid violence. Raphi is a source of fascination for the writer. When she first meets her, she is the opposite of what she expected; Cohen thinks she is similar to herself. "I thought if I could understand one woman's concrete motivation to box that it would count as a kind of explanation, even a justification, of why women might hunger for this experience more generally."

Implicit in this statement is the view that women need to have a justification for boxing. But Cohen never gets the explanation she wants from Raphi. She dismisses Raphi's initial responses; that it is to do with control, self-respect and mastery, amongst other factors. For Cohen this is not enough and the only person who has received the full account is Raphi's old coach.

The strong implication of this passage is that Raphi was once attacked by a man and wants to be able to hit back. Indeed, I think it is effective to hold back a full account of Raphi's motivation for doing what she does. It would appear almost trite to have a simple reason for her dedication. But I did not get the impression that Cohen keeps it secret because it is a mystery. Rather I thought it was a mystery to Cohen because she never allows herself to understand the other women in the gym. Throughout the book Cohen never loses the assumption that something is wrong with boxing. Even when she becomes involved in it, she considers this to be some dark aspect of her character and she tries to explore what is wrong with herself.

The best literature on boxing does address the ambiguity of its subject. Its artistry, which cannot be denied, is bound up with brutality. But it is the dark side of boxing, the hurt rather than the skill, that Cohen emphasises and she does not acknowledge the other women as athletes or boxers.

To be fair, she does get stuck in. She trains and spars but her approach to the subject is confusing. Unlike other examples of participatory journalism, she is always on the outside looking in. This could be the perfect position for a writer to be in, ideal for observation. But it clashes with the subjective nature of the experience she discusses.

She is writing in the first person and on what boxing means to her, which is entirely valid. But from her knowledge of this one gym she goes on to generalise about the sport as a whole and at the same time overlooks or downplays aspects of the story that do not interest her.

It is an irony not lost on Cohen that she is the only character in the book who remains boxing by the end of the story. But she never loses the preconceptions with which she entered the gym in the first place.

Without Apology, by Leah Hager Cohen, is published by Weidenfeld & Nicholson at £12.99.