Mechanisms to Reduce Mental and Physical Fatigue Following Exercise Training in Older Adults: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Mechanisms to Reduce Mental and Physical Fatigue Following Exercise Training in Older Adults (NCT05484661), a randomized na study. The primary outcome is Fatigue.

2. Clinical Question

The clinical question is whether adding branched chain amino acids (BCAAs) to an exercise program is associated with a different change in fatigue severity than adding placebo to the same exercise program in older adults. The registry record describes the study as examining fatigue following exercise training. Its primary outcome is the change in Fatigue Assessment Scale score from baseline to 8 weeks.

The question concerns the added supplement in the context of exercise, rather than exercise compared with no exercise. Both groups are described as receiving exercise, so the posted arm summaries cannot isolate the effect of exercise itself. The registry record does not report a separate group without exercise.

3. Trial Design

The study is listed as completed and randomized, with a parallel-group model and triple masking. Its phase is listed as not applicable. The registry record names The University of Texas Health Science Center at San Antonio as the sponsor. The recorded start date is 2022-12-22, and the primary completion date is 2023-11-30. Enrollment is listed as 20.

The two arms combine the same exercise program with different daily additions. The exercise protocol is described as high-volume, moderate-intensity, whole-body training, scheduled three times per week for eight weeks. One arm received BCAAs, described as approximately 7-10 g daily at 100 mg/kg. The other received maltodextrin placebo, also described as approximately 7-10 g daily at 100 mg/kg. The registry record does not report further details about how exercise sessions were supervised or adherence was assessed.

The primary outcome is change in fatigue severity score from baseline to 8 weeks. The arm summaries list 9 participants for Exercise + BCAA and 10 for Exercise + Placebo. The relationship between those outcome counts and the enrollment figure is not explained in the registry record. The registry record does not report whether participants were analyzed according to their randomized assignment or describe another analysis population.

Randomization is intended to make treatment groups comparable in expectation, while masking is intended to limit influences from knowledge of assignment. Those are general design principles, not evidence that balance or masking was achieved in this particular study. Details about the randomization procedure, who was masked, allocation concealment, protocol deviations, and adherence are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Fatigue, measured over change from baseline to 8 weeks.

The primary endpoint is change in fatigue severity score from baseline to 8 weeks. Participants completed the Fatigue Assessment Scale questionnaire. The registry description states that total scores range from 10, indicating the lowest level of fatigue, to 50, denoting the highest. The endpoint is reported as a mean change, with a standard deviation describing variation among participants in each arm.

Using change rather than a score at one time point can describe how participants’ scores shifted during the study period. In this endpoint, a negative change corresponds to a lower follow-up score than baseline; given the score direction described in the registry record, that represents a shift toward a lower fatigue score. This is a general interpretation of the scale and change-score convention, not a claim about the cause of any change.

Fatigue is the outcome of interest because the registry summary describes it as relevant to health outcomes in older adults and frames the study around fatigue following exercise training. The outcome is a questionnaire score, not a direct measure of exercise performance or a clinical event. The registry record does not report a threshold defining a clinically important change, a validation rationale for this particular population, or further details on questionnaire administration and scoring.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies the primary outcome as a continuous measure summarized by a mean and standard deviation. The statistical interpretation of such an outcome is different from a count or a time-to-event outcome: each participant contributes a numerical change score, and an analysis may compare the distribution of those scores between randomized groups. The record posts arm-level means, standard deviations, and participant counts, but it does not post a completed analysis of the between-group comparison.

What do the arm summaries convey?

General: the mean is the arithmetic average of observed values. It conveys the central tendency of the measured change but does not show whether all participants changed similarly. The standard deviation describes the spread of participant-level values around the mean. A larger standard deviation indicates greater dispersion on the score scale, but it is not the same thing as the uncertainty around the mean or the uncertainty around a treatment contrast.

The posted results list a mean change of -5.6 and standard deviation of 4.0 for Exercise + BCAA, based on 9 participants. For Exercise + Placebo, they list a mean change of -4.1 and standard deviation of 3.1, based on 10 participants. Those values are descriptive; the registry record does not provide a formal inferential estimate comparing the arms. No new contrast or uncertainty measure can be established from the registry entries as posted.

Why is a comparison estimate important?

General: a randomized trial’s treatment comparison is usually expressed as a contrast between groups, accompanied by a measure of uncertainty. The contrast addresses how outcomes differ between assigned groups, while the uncertainty measure indicates how compatible the data are with a range of possible underlying differences. A confidence interval is one common way to communicate that uncertainty. It is not a guarantee that the underlying effect lies within the interval, but it shows the precision of the estimate under the analysis assumptions.

For this study, the registry record does not report a contrast, confidence interval, or test result. It also marks the comparison as not estimable. Consequently, the posted means should not be converted into a claim of statistical significance or a precise estimate of the difference attributable to BCAA supplementation. The record does not state why the comparison was unavailable or not estimable.

What does the change score represent?

General: a change score is calculated from measurements taken at different times, with the direction depending on the subtraction convention. The registry identifies the outcome as change from baseline to 8 weeks, and the negative arm means are consistent with follow-up scores lower than baseline under the usual follow-up-minus-baseline convention. The record does not state the exact scoring or subtraction procedure beyond describing the endpoint as change from baseline to 8 weeks. The score range is 10 to 50, with lower scores indicating less fatigue.

Change scores and analyses that adjust for baseline can answer related but not identical statistical questions. Baseline adjustment can account for starting values and may improve precision in some settings. The registry record does not report whether the primary analysis used a direct comparison of change scores, a baseline-adjusted model, or another method. No statistical model, covariates, assumptions, or handling of repeated measurements is reported.

How should planning assumptions be read?

The registry record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These are assumptions for an illustrative sample-size calculation, not a reported justification for the trial’s enrollment. The registry record does not report the trial’s own sample-size justification or its planned effect size.

General: a sample-size calculation estimates how many participants may be needed under specified assumptions to detect an effect at a chosen significance level and power. A planning calculation is not the same as observed power after the data have been collected. It also does not establish that a study achieved a particular precision or that a comparison is statistically significant. No specific planning values are reported in the registry record.

General: the normal approximation is a mathematical approach that can be used to approximate the distribution of a statistic under specified conditions. Its appropriateness depends on the outcome, design, and assumptions. The registry record does not provide diagnostics or details sufficient to assess those assumptions for this trial. Equal allocation is the stated planning assumption; the posted endpoint counts are 9 and 10, and the record does not explain the difference between the planned allocation assumption and those counts.

What can be inferred about analysis quality?

General: transparent statistical reporting typically identifies the analysis population, method, estimate, uncertainty, and treatment of missing observations. Those details allow readers to evaluate what question was answered and how robustly. In this registry record, the analysis count is 0, and the primary comparison is not estimable. The analysis method, missing-data procedure, and analysis population are not reported in the registry record. This absence limits the interpretation of the arm summaries; it does not establish that no analysis was conducted outside the registry.

There is no discrepancy flag indicating that a sponsor analysis conflicts with a recalculation. No recalculated comparison is posted. The arm-level data should therefore be described as posted summaries, without substituting an unreported analysis or deriving a new treatment contrast.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Exercise + BCAA", "Exercise + Placebo")
n   <- c(9, 10)
m   <- c(-5.6, -4.1)
sp  <- c(4, 3.1)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Exercise + BCAA  9  -5.600  4.000  -8.675  -2.525
CARM  Exercise + Placebo  10  -4.100  3.100  -6.318  -1.882

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 1 outcome measure and 0 analyses, with no secondary outcomes posted. The listed primary outcome is change in fatigue severity from baseline to 8 weeks. A multiplicity plan, including any approach to controlling false-positive findings across outcomes or analyses, is not reported in the registry record. Since no inferential analysis is posted, there are no reported hypothesis tests to interpret in relation to multiplicity.

General: multiplicity arises when multiple statistical claims are tested, because repeated testing can increase the chance of at least one apparently notable result even when no underlying effect exists. Prespecifying primary outcomes and analysis procedures helps clarify which findings are confirmatory and how multiple comparisons are handled. The registry record does not report whether any additional outcomes or analyses were planned outside the posted record.

The arm-level endpoint counts are 9 for Exercise + BCAA and 10 for Exercise + Placebo, while total enrollment is 20. The registry record does not explain the relationship between enrollment and the analyzed outcome counts. It does not report whether any outcome measurements were missing, why the counts differ, or whether participants were excluded from the endpoint summaries.

General: missing-data methods can affect the interpretation of an estimate, particularly when missingness relates to outcomes or participant characteristics. Common reporting details include how much data were missing, reasons for missingness, and the method used to handle it. These details are not reported in the registry record. The analysis population—such as all randomized participants or a defined subset—is also not reported. No conclusions about attrition, imputation, or adherence to an intention-to-treat approach can be drawn from the posted information.

The record does not report a protocol-defined analysis plan, interim analyses, or analysis-set definitions. Their presence or absence outside the registry record cannot be inferred.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event entries list 10 participants at risk in each arm. In Exercise + BCAA, the registry reports 0 participants with a serious adverse event, 0 with another adverse event, and 0 deaths. Exercise + Placebo likewise lists 0 participants with a serious adverse event, 0 with another adverse event, and 0 deaths. No serious adverse-event terms are listed.

These entries describe the registry’s recorded counts for the groups and categories shown. They are not evidence that the possibility of an adverse event is absent. General: when no events are recorded in a study group, the data still have limited ability to characterize uncommon events, especially when the number of participants is small. A zero count does not establish zero risk.

The safety entries list 10 participants at risk in each arm, whereas the outcome summaries list 9 for Exercise + BCAA and 10 for Exercise + Placebo. The registry record does not explain why the counts differ. It also does not provide further detail about event ascertainment, follow-up duration for safety reporting, or events by severity apart from the serious and other categories. The listed adverse-event counts should therefore be read as registry summaries, not as a complete characterization of safety.

13. What the Result Does, and Does Not, Mean

The registry record supports a limited descriptive statement: the mean fatigue score change was negative in both randomized arms over the baseline-to-8-weeks period. The posted mean was -5.6 in Exercise + BCAA and -4.1 in Exercise + Placebo. The scale description identifies lower scores with less fatigue, so each arm’s average change was toward a lower score. The standard deviations and arm counts describe the spread and size of the posted summaries.

Those values do not establish whether adding BCAAs led to a different change than adding placebo. No inferential comparison is reported, and the registry record marks the continuous two-arm comparison as not estimable. There is no reported confidence interval or p-value to quantify uncertainty in a between-arm estimate. The arm means should not be treated as proof of an effect or of no effect.

The study question is narrower than whether exercise itself changes fatigue. Both arms received exercise, with BCAAs in one arm and placebo in the other. The design as listed can address the added supplement relative to placebo within that exercise program, but it does not include a group without exercise for estimating exercise’s effect. The record also does not provide a longer follow-up outcome, a clinically important difference threshold, or secondary outcome results.

General: statistical uncertainty and clinical importance are related but distinct. A sufficiently precise estimate can still be small in practical terms, while an imprecise estimate may be compatible with a range of effects. Without a reported between-arm estimate, uncertainty interval, and clinical-importance benchmark, neither the precision nor the practical importance of a treatment contrast can be assessed from this record.

The completion status and absence of recorded adverse events do not resolve the missing efficacy comparison. The most defensible conclusion is that the registry contains descriptive arm-level fatigue changes and safety counts, but does not report a statistical comparison capable of supporting a conclusion about the relative change between the arms.

14. Why This Trial Matters Statistically

This trial illustrates why arm-level results and a treatment comparison answer different statistical questions. The arm means describe average change within each group. A randomized comparison is needed to estimate whether outcomes differ between assigned groups, with uncertainty expressed in a suitable way. The registry record posts the former but does not report the latter for the primary continuous outcome.

That distinction matters particularly when both groups receive a shared intervention. Here, both arms are described as following an exercise program, and the assigned addition is BCAA or placebo. Any between-arm estimate would concern the added supplement in this context. A change within either arm cannot isolate the supplement’s contribution from shared exercise, time, attention, or other influences.

The record also demonstrates the importance of reporting participant counts consistently across outcomes and safety summaries. The primary outcome summaries list 9 participants in one arm and 10 in the other, while the safety entries list 10 at risk in each arm. The record does not explain this difference. Without an account of missingness and analysis populations, readers cannot determine precisely which participants contributed to each summary.

General: precision depends on the amount and variability of information, as well as the design and analysis. Means and standard deviations are useful, but they do not replace a treatment estimate with an uncertainty measure. Small arm counts can make estimates sensitive to individual observations; the registry record does not provide participant-level data for assessing that sensitivity.

The record’s status as completed does not guarantee that all planned results or analyses appear in the registry. The absence of a reported analysis limits what can be concluded from these entries, while leaving the descriptive values interpretable on their own terms. Clear reporting of analysis methods, missing data, and the primary comparison would be important for understanding the evidential strength of this trial.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The primary limitation for statistical interpretation is that the registry record does not report an analysis of the primary between-arm comparison. Although the arm-specific means, standard deviations, and outcome counts are listed, the comparison is marked as not estimable. No effect estimate, confidence interval, test statistic, or p-value is available in the registry record.

The outcome counts do not match the enrollment total, and the record does not explain the difference. It lists 9 participants for the Exercise + BCAA outcome and 10 for Exercise + Placebo, while enrollment is 20. The safety entries list 10 at risk in each arm. Reasons for the differing counts, missing outcome data, and the analysis population are not reported in the registry record.

The registry does not provide baseline fatigue summaries by arm, participant-level outcome data, or details about the statistical model. It is not reported whether the primary analysis compared change scores directly, adjusted for baseline, or used another method. The randomization procedure, allocation concealment, identities of those masked, adherence, and protocol deviations are also not reported in the registry record.

The primary endpoint is a questionnaire score measured from baseline to 8 weeks. The record does not report a clinically important difference threshold or outcomes after that follow-up. No secondary outcome results are posted. The results therefore cannot characterize longer-term fatigue changes or broader effects beyond the listed endpoint.

Finally, both arms received exercise, so the listed comparison does not isolate exercise versus no exercise. The registry record describes a planning illustration, but does not report a trial-specific sample-size justification. These omissions do not invalidate the posted descriptive summaries, but they restrict assessment of precision, analysis choices, and the scope of any treatment interpretation.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Mechanisms to Reduce Mental and Physical Fatigue Following Exercise Training in Older Adults — NCT05484661.
• Registry record last updated 2024-11-21; status last verified 2024-10.
• Results first posted 2024-11-21.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed, randomized, triple-masked, parallel study with enrollment of 20. It compares exercise plus BCAA with exercise plus maltodextrin placebo. The exercise program is described as three sessions per week for eight weeks, and supplementation is described as daily for eight weeks.

The primary outcome is change in Fatigue Assessment Scale score from baseline to 8 weeks. The posted mean changes are -5.6 (standard deviation 4.0; 9 participants) for Exercise + BCAA and -4.1 (standard deviation 3.1; 10 participants) for Exercise + Placebo. A statistical comparison is not reported and is marked as not estimable.

The adverse-event entries list 0 serious adverse events, 0 other adverse events, and 0 deaths in each arm. The registry record does not report secondary outcome results, analysis methods, missing-data procedures, or the analysis population. The entries support descriptive reading of the posted arm summaries, but do not establish a between-arm statistical conclusion.