Can Online Coaching Reduce MS Fatigue? The BIAMS Trial

Online physical-activity coaching may reduce fatigue for people with multiple sclerosis (MS), even after the program ends. That is the encouraging result from the BIAMS trial, a 318-person randomized controlled trial that tested a fully internet-delivered behavioral program against an attention and social-contact control. The result deserves attention because access is a real barrier in MS. It does not yet justify claims that an app can replace supervised exercise.

The trial found statistically significant improvements in fatigue severity at six months, sustained at 12 months—six months after the intervention stopped. But the publication reports p-values without mean differences, effect sizes, or confidence intervals. We know the fatigue results passed a statistical threshold. We do not know how large the improvement was, how many participants experienced a meaningful change, or how it compares numerically with other approaches.

What BIAMS tested

The 2023 BIAMS secondary-outcomes report randomized 318 people with MS to a six-month internet-delivered behavioral intervention designed to increase lifestyle physical activity or to an attention-control program with social contact. This was not a comparison with people who received nothing. That choice matters because participation, contact, and expectations can change self-reported symptoms.

The intervention did not prescribe a supervised gym routine or require clinic visits. It aimed to help participants increase overall daily physical activity through behavioral coaching. That makes the study more relevant to people whose symptoms, mobility, transportation, location, or schedules make supervised programs hard to sustain.

At the six-month assessment, the intervention group showed significant group-by-time effects on the Fatigue Severity Scale (FSS; p<.01) and the physical subscale of the Modified Fatigue Impact Scale (MFIS-physical; p<.05). Those differences remained significant at the 12-month follow-up. The timing is notable: the program had ended six months earlier, so the result is compatible with a durable behavior change rather than a short-lived boost from active coaching.

The benefit was selective. The trial did not find improvement in depression, anxiety, pain, sleep quality, walking function, or cognition. The reported MFIS-physical result should not be stretched into a claim that all dimensions of fatigue improved. The publication identifies the physical subscale as significant; it does not provide enough information here to confirm the result for every MFIS subscale.

Why the result carries weight

MS exercise studies are often small and short. BIAMS enrolled 318 participants, used random assignment, included an active attention-control condition, and followed participants for 12 months. Those features make it a stronger test than a typical waitlist-controlled, endpoint-only behavioral study.

The active control improves confidence that social contact alone did not explain the fatigue result. It cannot fully blind participants to which program they received, however. Participants who believe they are receiving a fatigue-focused intervention may change their behavior or report symptoms differently. Both FSS and MFIS are self-reported measures, so expectation and response bias remain plausible.

The broader evidence also supports physical activity as a fatigue-management tool in MS. A 2024 systematic review and meta-analysis found that exercise improved fatigue along with aerobic capacity, strength, and balance across MS populations, while also noting substantial variation among studies. A 2021 meta-analysis found that both aerobic and resistance training reduced perceived fatigue, with no significant advantage for either modality.

BIAMS extends that evidence into a different delivery model. It suggests that people do not necessarily need an in-person program to see a fatigue benefit. That is useful, but it is a narrower claim than saying remote behavioral coaching produces the same clinical range of effects as exercise training.

Supervised exercise has shown broader gains

Several trials and reviews point toward a wider outcome profile when participants complete structured, supervised exercise. In a randomized trial of progressive high-intensity aerobic exercise, Langeskov-Christensen and colleagues reported improvements in fatigue, walking, and cardiorespiratory fitness. A 2025 meta-analysis of high-intensity interval training also found reduced fatigue and improved exercise capacity in people with MS.

Other formats can improve the outcomes they train directly. A 2025 randomized trial of a seven-week, group-based outdoor walking program in 62 ambulatory people with MS improved walking capacity and mental well-being; participants completed two personalized, supervised moderate-to-high-intensity walking sessions each week. The study is summarized in the published report. A 2025 review of functional exercise training likewise describes modality-specific effects across fatigue, depressive symptoms, and health-related quality of life.

These results do not disprove BIAMS. They answer different questions with different interventions. A behavior-change program that encourages more lifestyle activity may reduce the physical burden of fatigue without providing enough intensity, progression, or task-specific practice to improve walking performance. Supervised programs can supply those ingredients, but they demand more access, time, staffing, and sometimes travel.

Domain-specific results are common enough in MS exercise research that BIAMS' pattern is scientifically plausible. In an early-MS randomized trial, Riemenschneider et al. found improved physical function without cognitive gains. A null cognitive result does not erase a physical-function result; it sets a boundary around it.

The missing numbers are a serious limitation

BIAMS reports that the fatigue findings were statistically significant, but it does not report effect sizes, mean between-group differences, or confidence intervals in the available publication record. This is the central limitation. A p-value answers whether the observed pattern was unlikely under a statistical null model; it does not tell a patient whether the average improvement was barely noticeable or large enough to change daily life.

The trial also does not report achieved physical-activity volume, objective activity measurement, dropout rates, or engagement metrics in the available record. Researchers therefore cannot show how much activity participants added, whether activity change mediated the fatigue result, or how easily a health system could reproduce adherence outside a trial. Improved self-efficacy or other engagement effects could have contributed, even with an attention-control condition.

Generalizability also remains uncertain. The available report does not describe the enrolled disability range in enough detail to establish how well the intervention applies to people with advanced MS. That gap matters because advanced MS can bring substantial physiological barriers. In a small study of 18 people with advanced MS, Chaves and colleagues documented impaired cardiorespiratory fitness and body composition. Behavioral support may still help this population, but BIAMS does not establish that it does.

Where this leaves patients and clinicians

For people with MS who cannot reliably attend supervised exercise, BIAMS supports a practical idea: structured remote support for increasing physical activity can reduce self-reported fatigue, and the effect persisted through six months after the program stopped. The trial's size, active comparator, and follow-up make that conclusion more credible than a glossy wellness claim built on a tiny uncontrolled pilot.

It remains one trial, without an independent completed replication for this exact fully internet-delivered behavioral approach and fatigue endpoint. A 2026 hybrid telerehabilitation randomized trial improved mobility and functional capacity, but it used structured rehabilitative content and targeted gait speed rather than fatigue; it is not a direct replication of BIAMS.

The sensible interpretation is modest: remote behavioral coaching is a plausible, accessible option for MS fatigue management, especially when supervised exercise is out of reach. It has not yet shown that it improves walking, mood, sleep, pain, or cognition, and its clinical effect size remains unknown. The next useful study should report those numbers, measure actual activity, identify who benefits, and test whether periodic supervised sessions can add broader functional gains.