RCTJadad 3/5RandomizedDouble-BlindPlacebo-Controlled

Creatine Nitrate + Caffeine: Sharper Focus, But Don't Expect a Strength Boost (Yet)

NutrientsMarch 7, 2024Vol. 16 (6)

Summary

If you stack a pre-workout containing both creatine and caffeine, you're probably hoping for bigger lifts and a mental edge. A 2024 study in Nutrients put that combo to the test — and the results split cleanly down the middle: your brain benefits, but your barbell numbers may not.

Researchers at Jacksonville State University ran a tightly controlled crossover trial with 12 resistance-trained men (2+ years of lifting experience). Each participant cycled through four 7-day supplement conditions, separated by a week-long washout: a placebo (maltodextrin), creatine nitrate alone (5 g/day, providing 4 g creatine + 1 g nitrate), caffeine alone (400 mg/day — roughly four cups of coffee), and the two combined. Because everyone tried every condition, each person served as their own control, which is a strength for a study this small. After each 7-day block, participants took their supplement 45 minutes before testing, then completed the Stroop Word-Color test (a classic measure of attention and mental "interference" control), bench press and leg press to failure at 70% of their one-rep max, and a 30-second Wingate cycling sprint test for anaerobic power.

The standout finding: combining creatine nitrate and caffeine significantly improved performance on the Stroop interference test — the hardest version of the task, where you have to name the ink color of a word that spells a different color (e.g., the word "red" printed in blue ink). The combo group outscored the creatine-only group (65.9 vs. 56.8 correct responses, p = 0.007) and showed a significantly bigger improvement from baseline than caffeine alone (p = 0.04). This lines up with a growing body of research suggesting creatine can support brain energy metabolism, especially under mentally demanding conditions, and that pairing it with caffeine may amplify activation in brain regions tied to executive function.

On the muscle side, the news was less exciting. None of the three supplements — creatine nitrate, caffeine, or the combo — produced statistically significant gains in bench press, leg press, or Wingate power compared to placebo. The one bright spot: both the caffeine and combo groups did significantly increase bench press reps-to-failure from their own baseline (about 2 extra reps, p = 0.04), more than the placebo group managed. But because the overall statistical interaction wasn't significant, this should be read as a modest, caffeine-driven trend rather than a proven strength boost from the combo.

Reassuringly, no adverse events occurred in any group, and blood chemistry (liver enzymes, lipids, complete blood count) and cardiovascular measures (heart rate, blood pressure) stayed stable across all four weeks — supporting the short-term safety of both ingredients, alone or combined, at these doses.

What This Means For You

For supplement shoppers: If your goal is sharper focus, quicker reaction under mental fatigue, or better decision-making during training or competition (think: sport-specific strategy, coding sprints, exams), this study supports pairing creatine with caffeine rather than using caffeine alone. The doses tested — 5 g/day creatine nitrate (≈4 g elemental creatine) and 400 mg/day caffeine (about 4 cups of coffee or 2 strong energy drinks) — are both within commonly available commercial ranges, though most people should start lower on caffeine (100–200 mg) to gauge tolerance, especially if not habituated to stimulants.

Timing: Both supplements were taken about 45 minutes before testing, which matches standard pre-workout dosing advice for caffeine. Creatine's timing is less critical — its benefits build from consistent daily intake, not a single acute dose, so once-daily dosing (pre- or post-workout) works fine.

For strength/power training: Don't expect this specific stack to move the needle on your lifts after just one week. The performance gains here were modest and inconsistent; creatine's well-documented strength benefits typically require weeks of loading (and this trial's 7-day window may simply have been too short to detect them). If pure strength/power is the goal, longer-term creatine monohydrate protocols (3–5 g/day for weeks to months) remain far more evidence-backed than a one-week creatine nitrate cycle.

Who benefits most: Athletes in sports demanding both cognitive sharpness and physical output (combat sports, team sports, tactical occupations) may see the most practical value from the cognitive effect. Who should be cautious: Anyone with caffeine sensitivity, arrhythmia, or cardiovascular conditions — this trial excluded such people, so results don't generalize to them.

Important Considerations

This was a small trial — just 12 participants, all young, healthy, resistance-trained men. Results may not generalize to women, older adults, beginners, or people with health conditions, all of whom were excluded by design. A sample this size is also underpowered to detect anything but large effects, so "no significant difference" for strength outcomes doesn't prove the supplements do nothing — it may simply mean the study couldn't detect a smaller true effect.

The 7-day washout between conditions was shorter than the 4-week period researchers consider ideal for fully clearing creatine's effects from muscle, meaning some carryover between conditions can't be ruled out. The study also didn't measure actual blood caffeine or muscle creatine levels, so we can't confirm participants absorbed and stored these compounds as expected.

"Creatine nitrate" is a specific, patented form combining creatine with a nitrate group; it's not interchangeable with plain creatine monohydrate (the cheaper, most-studied form) or with nitrate-rich foods like beetroot juice. Findings here may not apply to other creatine forms.

Only one cognitive outcome (the hardest Stroop subtest) reached significance out of many tested — a reminder that testing multiple outcomes increases the chance of a false positive. This finding deserves replication before being treated as established fact. As always, treat marketing claims that cite this single small study as definitive proof with skepticism, and consult a physician before combining stimulant and creatine supplements if you have cardiovascular or metabolic conditions.

Terms Explained

Creatine nitrateA compound combining creatine with a nitrate group, marketed as more soluble than creatine monohydrate and potentially boosting nitric oxide production for blood flow.

Stroop testA classic psychology test measuring attention and mental control by asking you to name the ink color of a word that spells a different color.

1RM (one-rep max)The maximum weight a person can lift for a single repetition of an exercise, commonly used to set training loads as a percentage (e.g., 70% 1RM).

Wingate testA 30-second all-out cycling sprint test used to measure anaerobic power output and fatigue.

Crossover trialA study design where every participant tries every treatment (including placebo) in random order, so each person acts as their own control.

Washout periodA break between treatments in a crossover trial meant to let a prior supplement's effects fully clear before starting the next one.

Effect size (partial eta-squared)A statistic showing how large a treatment's real-world impact is, independent of sample size or statistical significance.

Ergogenic aidAny supplement, food, or practice used to enhance physical performance.

Double-blind, placebo-controlledA study design where neither participants nor researchers know who received the real supplement versus an inactive placebo, reducing bias.

Technical Study Details

Study Design

Total Score

JADAD Quality Assessment

/ 5

評価詳細

Randomization

0 / 2

Is the study described as randomized?

Yes+1

Rationale: The article's abstract explicitly states the study was a "double-blind, randomized crossover trial," and the Methods section confirms "randomization of the study" and describes treatments administered "in a randomized fashion"/"randomized sequence," meeting the criteria for explicit description as randomized.

Is the method of randomization described and appropriate?

No-1

Rationale: The article repeatedly states that treatments were administered "in a randomized fashion" / "randomized sequence" and that "randomization of the study" occurred, but it never describes the actual method used to generate the randomization sequence (e.g., computer-generated random numbers, random number table). Since no specific, appropriate randomization method is described, this criterion should be scored "no" per Jadad scale guidelines, which require the method to be both mentioned and appropriate — mere assertion of randomization without describing the technique does not satisfy the criterion.</rationale> </invoke>

Blinding

2 / 2

Is the study described as double-blind?

Yes+1

Rationale: The abstract explicitly states the trial was conducted as a "double-blind, randomized crossover trial," and the Supplementation section (2.2.4) confirms "The study maintained its double-blind design using identically encapsulated supplements distributed in coded containers," directly meeting the criterion for describing the study as double-blind.

Is the method of blinding described and appropriate?

Yes+1

Rationale: The article explicitly states the study used a double-blind design with identically encapsulated supplements in coded containers, and the dosing formulations were designed so that each condition (CN, CAF, CO, PL) totaled the same overall weight (via maltodextrin filler) to preserve blinding across conditions. This constitutes an adequately described and appropriate blinding method (identical-appearing encapsulated products with matched filler), satisfying the Jadad criterion for appropriate blinding.

Dropouts/Withdrawals

1 / 1

Is there a description of dropouts and withdrawals?

Yes+1

Rationale: The article reports the initial number of interested participants (15), the number excluded (3) with specific reasons given for each (one due to medical screening results, two due to scheduling conflicts), and confirms that the remaining 12 completed all four conditions of the crossover study. This satisfies the Jadad criterion of describing the number of and reasons for withdrawals/dropouts, even though in this crossover design all analyzed participants completed all treatment arms so there were no differential per-group withdrawals after randomization."

Study Population

Sample Size12

Age Range-

ConditionResistance-trained male athletes

Inclusion Criteria

At least two years of experience in multi-joint resistance training

Interventions

Creatine Nitrate

Treatment

Dose5 g/day

Frequencyonce daily (pre-workout on exercise days, midday on non-exercise days)

Duration7 days

Routeoral

Caffeine

Treatment

Dose400 mg/day

Frequencyonce daily (pre-workout on exercise days, midday on non-exercise days)

Duration7 days

Routeoral

Creatine Nitrate + Caffeine (Combination)

Treatment

Dose5 g/day creatine nitrate + 400 mg/day caffeine

Frequencyonce daily (pre-workout on exercise days, midday on non-exercise days)

Duration7 days

Routeoral

Placebo (maltodextrin)

Control

Dose5.4 g/day

Frequencyonce daily (pre-workout on exercise days, midday on non-exercise days)

Duration7 days

Routeoral

Outcomes

Outcome	Type	Effect	p-value
Leg Press Lifting Volume	Primary	-	-
Bench Press Repetitions to Failure (70% 1RM)	Primary	-	p = 0.04Significant
Bench Press Lifting Volume	Primary	-	-
Leg Press Repetitions to Failure (70% 1RM)	Primary	-	-
Wingate Peak Power	Primary	-	-
Wingate Mean Power	Primary	-	-
Wingate Minimum Power	Primary	-	-
Wingate Total Work	Primary	-	-
Wingate Fatigue Index	Primary	-	-
Stroop Word Test	Primary	-	-
Stroop Color Test	Primary	-	-
Stroop Word-Color (Interference) Test	Primary	0.16	p=0.007Significant
Stroop Total Counts	Primary	-	-
Readiness to Perform Exercise	Secondary	-	-
Sleep Quality	Secondary	-	-
Heart Rate and Blood Pressure	Secondary	-	-
Blood Chemistry Panel (CK, LDH, ALP, AST, ALT, lipid profile, CBC)	Secondary	-	-

Safety

Adverse Events0

Serious AEs0

Dropout Rate0.0%

No adverse events were reported throughout the 7-day supplementation periods across any treatment (PL, CN, CAF, CO). Blood chemistry (CK, LDH, ALP, AST, ALT, lipid profile, CBC) and cardiovascular hemodynamics (HR, BP) remained stable and within standard clinical ranges with no significant treatment-related effects, supporting short-term safety of creatine nitrate and caffeine alone and combined.

Conclusion

Co-ingestion of creatine nitrate and caffeine for 7 days improved cognitive function, particularly performance on the Stroop Word-Color interference (cognitive interference) test, compared with creatine nitrate alone and, for change-from-baseline, compared with caffeine alone. No supplement (creatine nitrate, caffeine, or their combination) produced statistically significant improvements in bench press, leg press, or Wingate anaerobic performance versus placebo, although mean bench press repetitions to failure increased significantly from baseline in the caffeine and combination groups versus placebo. No adverse events were reported and blood chemistry/cardiovascular parameters were unaffected, supporting short-term safety of both supplements alone and combined.

Limitations

Washout period was 7 days, shorter than the ideal four weeks, due to practical constraints
Study limited to resistance-trained male athletes, which may not represent broader or gender-diverse populations
Sample size, while sufficient for statistical analysis, might not capture individual variability
Did not assess peak blood caffeine levels, nitrate levels, or muscle creatine content
Lack of strict dietary control and reliance on self-reported dietary/side-effect data