Perimenopause creatine: a sleep consistency signal

The sleep result deserves a different headline from the cognition result. At week 6, baseline-adjusted sleep consistency was 7.4 percentage points higher with creatine than placebo (p=0.015). Stroop reaction time improved over time in both congruent (p＜0.001) and incongruent (p=0.004) conditions, with no group differences. Training-related improvement in reaction time therefore cannot be credited to creatine alone.

What did the groups actually receive?

The randomized study enrolled 51 perimenopausal women aged 46 ± 5 years: 18 received creatine monohydrate, 20 placebo, and 13 entered a non-training control group. The creatine and placebo groups followed a five-day loading schedule of 20 g/day followed by approximately 4.5 g/day maintenance, alongside six weeks of progressive high-intensity resistance training twice weekly. This design tests the supplement alongside a training program; it does not compare loading against starting directly with maintenance.

Sleep consistency showed a time × treatment interaction (p＜0.001). The post-training prefrontal oxygenation contrast during Stroop had p=0.003. Oxygenation measured with fNIRS is a physiological outcome, not interchangeable with better test performance. The assessments included Stroop and the Rey 15-item memory test, with cognitive and oxygenation measures at baseline and before and after training. Sleep was tracked with a WHOOP wristband; daily symptom reports covered temperature sensitivity, fatigue, soreness, brain fog and bloating. Measuring those symptoms does not establish that the supplement improved every one of them.

How can a lifter separate supplement and training records?

1. Place supplement intake, sleep schedule and symptom notes on the same dated record.
2. Track sets, repetitions and RIR so changes in training are visible alongside changes in sleep.
3. Review Big 3 records and fairlift Muscle Index separately; sleep consistency is not a measure of strength gain.

These are logging suggestions, not an individualized protocol demonstrated by the trial. For the distinct question of product form, see choosing creatine monohydrate. The authors call this an exploratory analysis. Its findings do not establish longer sleep, a creatine-specific reaction-time benefit or treatment of menopause symptoms as a whole. The oxygenation and consistency signals are reasons to study the question further, not substitutes for the outcomes they might eventually help explain.