Fitness, Ageing, and Bilingualism (FAB): The Benefits of Regular Exercise and Bilingualism for Language Abilities in Healthy Ageing.

University of Agder233 enrolled

Overview

This project investigates the relative benefits of regular physical activity and bilingualism for ameliorating cognitive decline in healthy ageing, with a particular focus on language function. The randomized intervention component tests whether improving fitness via a home-based HIIT program leads to changes in fitness and related cognitive/language outcomes in older adults.

This project will determine the relative benefits of regular physical activity and bilingualism for the amelioration of cognitive decline in old age. Our project focuses on language because it is a core aspect of human cognition, which has received surprisingly little attention in ageing research given its tremendous impact on well-being. Our own previous research has demonstrated that healthy older adults experience a decline in language function, which is characterized by word finding difficulties, slower and more disfluent sentence production, and slower and less accurate sentence comprehension. Such language problems impact older adults' functioning and can lead to social withdrawal and loneliness. The current project, therefore, investigates how to ameliorate such language problems, as well as other forms of cognitive decline in healthy ageing. Two ameliorating factors that have received a lot of attention are bilingualism and regular physical activity, which have been shown to reduce the structural and functional brain decline associated with healthy ageing and to confer cognitive reserve, i.e. resilient cognitive performance. Currently, however, it has only been established that bilingualism and regular physical activity provide benefits for non-linguistic aspects of cognition, such as executive functioning, working memory, and processing speed. What is currently lacking is knowledge about the effects of exercise on language abilities in healthy ageing. Many language processes are isolated from, and independent of, other cognitive faculties. For example, word finding difficulties are not failures of long-term memory, as word knowledge increases with age, but the ability to successfully access words decreases. We have already demonstrated that fitter older adults experience fewer word finding difficulties than unfit older adults. In the current project, we aim to establish for the first time a causal relationship between physical exercise and ameliorated language decline in healthy ageing. To this end, we will conduct an aerobic exercise intervention and quantify increases in fitness levels and physical changes due to the intervention. We will examine the effects of these changes on language function in mono- and bilingual older adults. Moreover, using neuroimaging, we will investigate the neural changes underlying the benefits of exercise for language. Our study will thus provide new knowledge about how best to maintain language abilities across the lifespan. Furthermore, ameliorating language decline might be even more crucial for bilinguals than monolinguals, as bilingualism, even in young adults, has measurable costs for linguistic processing. Bilinguals have slower and less fluent word retrieval in both languages and more frequent word finding failures than monolinguals. Previous research provides competing accounts of these deficits, attributing them to either competition between languages during production or to the reduced frequency of use of a given language compared to monolinguals. Critically, these mechanisms may be differently affected by ageing. This is because with age, executive control declines, but language use accrues. Our research will therefore test these alternative theories about language decline in ageing bilinguals. We will also collect detailed information on the individual characteristics of bilinguals, which will allow us to identify those variables of bilingualism that serve to protect against decline in ageing. The study will be run across two institutions: the Universities of Agder (Norway) and Birmingham (UK).

Conditions

Healthy Ageing Cognitive Decline Cardiorespiratory Fitness

Interventions

Home-Based HIITOTHER

Participants will complete a 26-week home-based HIIT program comprising simple circuit training once per week and interval training twice per week. A 26-week dose will be targeted; if interruptions occur (e.g., illness, travel), the intervention period will be extended to ensure completion of 26 weeks of exercise sessions. The first four weeks will constitute a familiarization period with sub-maximal sessions, training equipment familiarization (Polar Unite watch and Polar H9 chest sensor), and instructional videos. Subsequent sessions will target high intensity (≥80% of HRpeak). Training will be guided by a personal exercise coach via emails, phone calls, and face-to-face meetings once weekly during the familiarization period and monthly thereafter. Participants will use a Polar Unite watch and Polar H9 chest sensor; the watch will be pre-programmed to display %HRpeak in real time during sessions. Exercise data will be extracted using Polar Flow software.

Eligibility

Sex: ALLMin age: 60 YearsMax age: 85 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Non-smokers for at least 5 years prior to enrollment. * Normal or corrected-to-normal vision and hearing. * No diagnosed language impairments (e.g., dyslexia, stuttering). * No illness or disease that would prevent safe participation in high-intensity interval training (HIIT). * Self-reported not meeting global physical activity recommendations (i.e., \<150 minutes/week of moderate-intensity physical activity). * Norway only: Written health certificate from the participant's general practitioner confirming eligibility for participation. Exclusion Criteria: * Any cardiovascular, metabolic, respiratory, neurological, kidney, liver, or cancer disease that would prevent safe participation in HIIT. * United Kingdom only: Severe electrocardiogram abnormalities (e.g., ST depression, long QT, heart block, wide QRS). * United Kingdom only: Elevated blood pressure at screening (systolic \>160 mmHg and/or diastolic \>90 mmHg).

Locations (2)

University of Agder

Kristiansand, Norway

University of Birmingham

Birmingham, United Kingdom

Outcomes

Primary Outcomes

Aerobic fitness - VO₂peak

Direct measurement of maximal oxygen uptake during a standardized progressive treadmill walking protocol to volitional fatigue. Participants complete 2-7 min self-paced level walking before the test. The test starts at 3.8 km/h with 4% incline; after a 4-min warm-up/stabilization, incline increases 3% every 4 min until blood lactate is 2.1 mmol/L above baseline, then incline increases 2% per minute up to 20%, followed by speed increases of 0.5 km/h per minute to exhaustion. VO₂peak is defined as the average of the highest 30-s VO₂ values. Test validity requires RER ≥ 1.10 or Borg ≥ 17.

Time frame: Baseline; 26 weeks (post-intervention)

Language function - Tip-of-the-tongue (TOT) task

Participants read definitions and attempt to name the target word (e.g., "A young swan" → "cygnet"). After each item they indicate Know, Don't Know, or Tip-of-the-tongue. The behavioral task includes 60 items (30 cognates; 30 non-cognates). Separate stimulus sets are used for English vs Norwegian, and for pre- vs post-intervention testing. Outcomes include probability of Know and TOT vs Don't Know (knowledge) and TOT vs Know (TOT probability).

Time frame: Baseline; 26 weeks (post-intervention)

Language function - sentence production (speeded picture description)

Speeded picture description to elicit phrases varying in type (coordinate vs prepositional clauses) and complexity (simple vs adjective-modified phrases). Stimuli comprise 20 image pairs, each appearing once in each of four conditions (within-items; within-subject). Outcomes include speech onset latency (RT) for correct responses and accuracy (correct clause produced). Separate stimulus sets are used for English pre, English post, Norwegian pre, and Norwegian post.

Time frame: Baseline; 26 weeks (post-intervention)

Language function - sentence comprehension (auditory word monitoring)

Participants make a speeded button press when they hear a pre-specified target word embedded in auditory input. Targets appear in unstructured lists, meaningful sentences with low target probability, and meaningful sentences with high target probability. Each stimulus set contains 60 items arranged across lists using a Latin square design. Outcome is reaction time measured from speech onset to button press for correct trials (and accuracy as applicable). Separate sets are used for English pre, English post, Norwegian pre, and Norwegian post.

Data from ClinicalTrials.gov

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Secondary Outcomes

Aerobic fitness - blood lactate concentration

Capillary blood lactate sampled by finger prick after each 4-min stage and 1 min after test termination during the graded treadmill protocol. Lactate is used to characterize metabolic response and thresholds (including the point where lactate reaches 2.1 mmol/L above baseline, which triggers the subsequent ramp).

Time frame: Baseline; 26 weeks (post-intervention)

Physical function - handgrip strength

Standing dynamometer test; participants instructed to grip maximally without pressing against the body. Three attempts on each hand with 30-s rest between attempts. Outcome is the best of three attempts per hand (kg), used for analysis.

Time frame: Baseline; 26 weeks (post-intervention)

Physical function - 30-second chair stand

Counts number of correct full stands from seated position within 30 seconds without using arms. If the participant is more than halfway up at 30 seconds, it counts as a full stand. Outcome is total number of correct stands.

Time frame: Baseline; 26 weeks (post-intervention)

Physical function - chair sit-and-reach (hamstring flexibility)

Participant sits on chair edge, extends one leg with heel on floor and foot flexed, reaches forward toward (or past) toes and holds 2 seconds. Outcome is distance in cm from toe: negative if short, positive if beyond toe; best score retained.

Time frame: Baseline; 26 weeks (post-intervention)

Physical function - back scratch (shoulder flexibility)

One hand reaches up the spine from lower back while the other reaches down behind the neck; distance between middle fingertips measured to nearest 0.5 cm. Outcomes recorded for right/left arm over; positive values indicate overlap, negative indicate gap; one attempt per side.

Time frame: Baseline; 26 weeks (post-intervention)

Physical function - 8-foot up-and-go (mobility/agility)

Participant rises from chair, walks 8 ft (2.438 m) around a cone/marker, returns to sit as quickly as possible. Outcome is time (s) from "go" to sitting; record to nearest 0.1 s and use best (lowest) time.

Time frame: Baseline; 26 weeks (post-intervention)

Physical function - one-leg standing balance (OLSB)

Participant stands on preferred leg with the other foot off the floor and attempts to maintain balance. Performance is coded relative to 5 seconds: \<5 s = "abnormal"; ≥5 s without difficulty = "normal"; ≥5 s with apparent difficulty = "adaptive". (If your registry requires a single numeric outcome, additionally record time in seconds.)

Time frame: Baseline; 26 weeks (post-intervention)

MRI - structural T1-weighted imaging

High-resolution T1-weighted structural scan (1 mm isotropic) acquired on a Siemens PRISMA 3T with 32-channel head coil (TR 2000 ms; TE 2.01 ms; TI 880 ms; flip angle 8°; FOV 256×256×208 mm; \~4:52 min). Outcomes include structural brain measures such as grey matter volume/density.

Time frame: Baseline; 26 weeks (post-intervention)

MRI - task fMRI

Multiband EPI-BOLD task fMRI while completing a TOT task; 2.5 mm isotropic, TR 1500 ms, TE 35 ms, phase encoding A→P; four runs (\~12.5 min each; \~50 min total). Pre/post contrasts include TOT \> Know, Know \> Don't Know (and exploratory TOT \> Don't Know).

Time frame: Baseline; 26 weeks (post-intervention)

MRI - resting-state fMRI

EPI-BOLD fMRI; participants will undergo an eyes-open resting-state sequence (participants fixating on white fixation cross on black background). Imaging parameters are the same as task-fMRI. Duration 7-8 mins.

Time frame: Baseline; 26 weeks (post-intervention)

MRI - perfusion

A multi-inversion time (multi-TI) pseudo-continuous arterial spin labelling (PCASL) will be used to acquire quantitative perfusion measures (in ml/100g/s) over the brain at rest. This sequence will also allow the arterial transit times (in s-1) to be measured.

Time frame: Baseline; 26 weeks (post-intervention)

Health-related quality of life - SF-12

MOS 12-item Short-Form Health Survey (SF-12). Outcome is SF-12 score(s), where higher scores indicate better health/quality of life.

Time frame: Baseline; 26 weeks (post-intervention)

Lung function - forced expiratory manoeuvre (FVC)

Spirometry-based forced vital capacity: maximal volume exhaled during a forced expiration following maximal inspiration, expressed in litres at BTPS. Test conducted seated with nose clip and coached maximal effort.

Time frame: Baseline; 26 weeks (post-intervention)

Lung function - forced expiratory manoeuvre (FEV₁)

Spirometry-based forced expiratory volume in 1 second: maximal volume exhaled in the first second of a forced expiration from full inspiration, expressed in litres at BTPS.

Time frame: Baseline; 26 weeks (post-intervention)

Lung function - maximum voluntary ventilation (MVV)

Participant breathes as rapidly and deeply as possible for 12 seconds (target \~90-110 breaths/min), seated with nose clip; two attempts with 2-min rest. Outcome is MVV expressed as L·min-¹ at BTPS.

Time frame: Baseline; 26 weeks (post-intervention)

Ventilatory mechanics - exercise flow-volume loop overlap (ventilatory constraint)

During graded treadmill testing, tidal flow-volume loops are plotted within the maximal flow-volume envelope. Mean of three tidal breaths over the last 30 s of each 4-min stage are recorded, with inspiratory capacity manoeuvres used to correct drift. Outcome includes degree of ventilatory constraint (e.g., % overlap).

Time frame: Baseline; 26 weeks (post-intervention)

Physical activity levels - accelerometry (ActiGraph GT3X+)

Participants wear an ActiGraph GT3X+ for 7-day monitoring periods to quantify physical activity patterns during the intervention. Monitoring occurs at start, mid-point, and end of the intervention; outcomes can include time in intensity bands (e.g., MVPA) and overall activity counts, per analysis plan.

Time frame: Baseline (start of intervention); mid-intervention; 26 weeks (end/post-intervention)