By Casey Chalk.

The gym is a near occasion of sexual temptation. At least mine is. Whenever I go, this husband and father of six, who is waging a losing battle against the notorious "dad bod," has to navigate around scores of attractive twenty- and thirty-something females wearing clothes that in an earlier, more "prudish" age, would have been considered embarrassingly inappropriate for mixed settings. I just do my best to keep focused on the reps and reading my Magnificat between sets.

More recently though, I've been inclined to pray, both for the attractive, often near-perfectly fit women, as well as their confident and muscular male counterparts. For beneath all the nauseating, self-absorbed posturing of gym culture is, I think, a deep sadness. What, exactly, are we all doing there? For sure, "maximizing" our health, as it were (though I prefer to invert it and jokingly call it warding off death). Yet I doubt most young folk see it that way - death is far too distant for them. They are there, whether they admit it or not, because they want to be beautiful. But to what end?

Presumably, most of my gym confreres are either in romantic relationships or looking for one - though, curiously, Gen Z'ers are having less sex than previous generations, as much recent reporting has noted. Our culture seems no less obsessed with sex than it was in earlier decades, but that obsession is now a digital and online one, performed (and consumed) in front of screens, often alone. At the gym, there are many beautiful, hyper-sexualized bodies. . .but at least some of them are actually engaging in less sex. Many will choose never to have children.

Catholic teaching would say this reflects a fundamental failure to appreciate what sex (and sexuality) are for, as Catholic theologian and professor Eduardo Echeverria persuasively argues in his new book Redeeming Sex: The Battle for the Body. Echeverria's text is deeply philosophical and theological - with extended chapters on the hermeneutics of meaning and truth, Christian anthropology and personalism, and differing understandings of divine revelation. That depth may deter readers with only a passing knowledge of these concepts. Yet his perspective is also aimed to be both accessibly practical and passionately ecumenical - indeed, I can think of few Catholic scholars with as much familiarity with contemporary Protestant theology as Dr. Echeverria.

For my purposes here, however, I want to focus my attention on what Redeeming Sex has to say about the kinds of struggles experienced by the kinds of people I see every week at the gym. As much as the careful, scientific refining of the human body in the gym has to do with sexuality, it can't help but tend towards a certain type of vanity and self-gratification. We aim for a more attractive body, because we want to feel good about ourselves and be celebrated by others, and we hope to attract the attention of one whose physicality is approximately as toned and beautiful as ours.

And the more our conception of beauty is defined by what we see on screens, be it social media, sensual images, or downright pornography, the more sex becomes wrapped up in ourselves and satisfying physiological inclinations.

Yet as Echeverria argues, reducing sexuality to mere physical and biological desire, based on a materialistic anthropology, "blocks self-transcendence and hence makes it impossible for the individual to be fulfilled in a relationality." In effect, if sexuality is not self-gift, it will necessarily devolve into self-indulgence, as Pope John Paul II argued in his classic text Love and Responsibility.

And self-indulgence reflects a narrowing of the human horizon, a turning inward that in its narcissistic self-worship resembles Gollum, a shameful, sniveling, and entirely unscrupulous individual whose entire identity revolves around pleasing himself.

"Preoccupation with self-egoism generates a contradiction between our individual self-affirmation and being fulfill...