Fatigue Is Stealing Strokes—Here’s the Proof (And the Solution We Already Built)

Golf Digest recently ran a fascinating test as part of their “MythBusters” series—this time tackling a question that’s been debated for years:

How much does fatigue really affect your golf swing?

It’s one of those things that golfers instinctively feel—especially on the back nine—but rarely see measured with any kind of structure. Until now.

🔗 Read the full Golf Digest article here.

What Golf Digest Did

Two of their staffers—one a scratch player, the other a mid-handicap—put this to the test. They hit full sets of shots with a 9-iron and a driver in two different states:

1. Fully rested – measured by a Whoop fitness tracker (strain < 6.0)

2. Fully fatigued – after a strenuous cardio workout that elevated their strain score to over 13.0, which mirrors what you'd see in a competitive 18-hole round

For each session, they tracked:

• Swing speed

• Ball speed

• Carry distance

• Dispersion

What They Found

As expected, performance dropped once fatigue set in. But here’s what stood out:

• Carry distances fell—up to 7 yards shorter with the driver

• Clubhead and ball speeds declined across the board

• Dispersion increased, especially with the driver (some shots going 11 yards more offline)

• And both players reported how their legs felt slower and shoulder turns were harder to complete

And remember—this was after one workout. Imagine the cumulative fatigue in tournament settings or long competitive rounds.

Why DF-18 Exists

When we built DriveForce, we didn’t need lab data to tell us fatigue was costing golfers strokes. We heard it firsthand from coaches, players, and teaching pros:

• “I always fall apart on the final few holes.”

• “It’s like my brain checks out around hole 14.”

• “My body just doesn’t respond the same near the end of the round.”

We knew golfers were treating the game like a sprint, when in reality, it’s a 4+ hour physical and mental endurance challenge.

So we created DF-18—a single-serving, pre-round formula engineered to:

• Support hydration and stamina

• Promote blood flow and muscle endurance

• Enhance cognitive focus

• Help you stay consistent through 18

And the Results Are Speaking for Themselves

• The Colorado Christian University men’s team was the first collegiate team to use DF-18 for a full competitive season. That same year, they became Division II National Champions, with players and coaches crediting DriveForce as a key part of their ability to finish strong under pressure.

• Dave Bisbee, Director of Golf at Seven Canyons, saw a measurable drop in his scores on the final 4 holes—going from consistently finishing over par to under par after adding DF-18 to his routine. That’s a 4-stroke swing, just by fixing the fatigue factor.

And these are just two examples. We've seen it across weekend golfers, junior players, tour coaches, and elite amateurs. If you want more proof, just scroll through our Instagram page:
👉 @driveforcegolf

The patterns are everywhere:
Finish strong. Play focused. Stay consistent.

Golf Digest just confirmed the science behind what we already knew from the field.

Fatigue is real. DF-18 is the solution.

Let’s keep proving it.