The deck is stacked against us. Labor-saving gadgets, electronic entertainment, and an information economy encourage us to value our minds more than our bodies. Even Christians with an orthodox theology of the body often live more like disembodied minds than enfleshed souls made to move. Exercise feels like a worldly pursuit at best or a vanity project at worst.

In A Little Theology of Exercise: Enjoying Christ in Body and Soul, David Mathis, executive editor for Desiring God and a pastor of Cities Church, invites readers to theologically reflect on their bodies in motion. In a world where movement has been largely outsourced to machines, where fitness is often pursued for self-glory, and where sedentary habits are the default, Mathis offers a warm, wise, and winsomely biblical call to steward the gift of physical exertion for God’s glory and our good.

The need to focus on exercise is a relatively recent phenomenon. “The innovations and seeming progress of modern life,” Mathis writes, “have made sedentary lifestyle more normal than ever before” (10–11). What previous generations received through daily labor, we now must pursue deliberately through scheduled workouts. Christians need a theology of the body that affirms good stewardship while avoiding the excesses our culture can draw us toward.

Some Value

Bodily training, as Paul tells Timothy, is of some value (1 Tim. 4:8). In a world where movement has become optional, that “some” matters more than ever. Mathis makes a compelling case that physical exertion is a gift from God, not an obstacle to spiritual joy. “Exercise makes happier humans,” he writes, “and God made humans to be happy—in him—with bodily movement being an assistant, rather than an adversary, to Christ-exalting joy” (2).

Mathis isn’t trying to sanctify gym culture or sell a new fitness tracker. He simply wants Christians to remember that our bodies were made on purpose and for a purpose. “We do not escape the body to glorify God,” he says, “but glorify God in [the] body” (23). That means our workouts—however modest—should be shaped not by the world’s obsession with image but by the Word’s call to love, serve, and rejoice.

As a result of this different focus, Christians should evaluate exercise differently from unbelievers. One option is to consecrate our movement through prayer. “Don’t exercise with the presumption of unbelievers,” he writes, “but consecrate your workouts—make them holy—through the word of God in prayer” (3). Instead of seeking distraction through electronics as we sweat, we can pursue communion with God.

In the middle of the practical tips, we encounter the mystery of body and soul. Spiritual health is ultimate, but physical health supports it. “When my muscles and lungs are in good condition,” Mathis writes, “I’m better prepared to glorify him in my body—not just while exercising, but in all of life” (51). Yet there’s more than just spiritual benefits in play.

Practical Benefits

Movement sharpens the mind, strengthens the will, and positions us to serve with greater energy and endurance. As an avid fitness enthusiast (I’ve done CrossFit, jujitsu, and Tough Mudders), I’ve certainly found this to be true.

Pursuing physical fitness has real, practical benefits, both immediate and long-term. I’ve noticed over the years that when my body is disciplined, my spiritual life tends to follow.

Pursuing physical fitness has real, practical benefits, both immediate and long-term.

Regular exercise forces me to plan my time, resist laziness, and push through discomfort. These are the same “muscles” I flex in daily Bible reading, prayer, and ministry. Mathis observes, “Exercise has helped me acquire a mentality to tackle tasks instead of to resist, procrastinate, and avoid” (73).

Movement energizes the mind. According to Mathis’s research, “Exercise helps to develop new brain cells, encourages binding of those cells, and improves our focus and eagerness to learn” (62). A short workout sometimes clears the mental fog that was making prayer or sermon prep feel impossible. Exercise isn’t magic, but it helps.

Over the long haul, fitness is a form of stewardship. One of my personal goals is to one day be a highly functional 70-year-old. I want to be the kind of grandfather who can carry my grandkids on my shoulders, take long walks with my family, kneel in prayer without groaning, and serve others with strength and vitality well into old age. That means I’m training today for a fruitful tomorrow. Exercise isn’t just about aesthetics and athleticism; it’s an investment in future faithfulness. That mindset changes the way I approach the gym.

Fit for a Purpose

Exercise prevents me from falling into two serious sins: sloth and idolatry. When I stop caring about my body, I drift toward passivity and excuse-making, and I become slothful. When I overprioritize fitness, I start building my identity around performance or image, which is a form of idolatry.

But when fitness is tethered to calling and is viewed as fuel for long-term ministry, exercise finds its rightful place. It’s not ultimate, but it’s important.

When fitness is tethered to calling and is viewed as fuel for long-term ministry, exercise finds its rightful place.

The heartbeat of this little theology of exercise is that redeemed bodies should be used in the service of joy, love, and mission. Mathis summarizes his perspective like this: “Enjoyment of Christ is sweetened by the modest use and upkeep of our bodies. God did not make them to sit around only. He made them to meditate on his words, yes, and then to move into the world toward needs” (91–92).

Mathis’s book isn’t a manual for fitness; it’s a primer in physical faithfulness. In a fitness-obsessed yet spiritually passive age, Mathis addresses contemporary problems with precision. Thus, this concise book will serve both the sedentary and ultrafit well by pointing them toward the proper end of exercise. A Little Theology of Exercise is an accessible resource for church members and pastors trying to sort out how stewardship of the body fits within a robust Christian lifestyle.