The Umeå High-Intensity Training Study

Maximum oxygen uptake (VO2 max)

Measured using standardized tests covering: episodic memory (free recall, paired associates), executive functions (n-back, Trail Making Test (TMT) 4, flanker task), visuospatial ability (spatial relations), working memory (digit span) and processing speed (Trail Making Test (TMT) 2 and 3). The cognitive tasks are first z-transformed and then everaged to form a unit-weighted cognitive score as well as domain specific constructs.

Assessed using functional MRI (fMRI) using two paradigms. Test A will estimate functional brain response during working memory manipulation and maintenance. Test B will estimate brain response during a pattern completion/separation paradigm. Separate analyses will be performed for fMRI paradigm A and B respectively. For each paradigm changes of % signal BOLD change will be analysed.

Assessed using standard MRI-sequences including T1w, T2w, T2-FLAIR. For structural MRI data volume (mm3) and cortical thickness (mm) will be the unit of measure.

Maximal isometric strength in knee extensor measured as normalized joint torque in newton meters per kilogram bodyweight (Nm/kg).

Maximal hand grip strength measured as normalized force in Newtons per kilogram bodyweight (N/kg).

Leg extensor power in the Nottingham Power Rig, measured as peak power output (watt).

Chair-stand test, number of chair-stands during 30 seconds.

One-leg stance: number of seconds able to stand on one leg (maximum 120 seconds).

Step test, number of steps during 30 seconds.

Hospital anxiety and depression scale (HAD): range 0-42, higher score indicates more symptoms.

Short Form Health Survey (SF-36): scores transformed to 0 to 100, higher scores indicates better quality of life.

Swedish Exercise Self Efficacy Scale (ESES-S): Range 10-40, higher score indicates more self efficacy.

One question (no. 3) regarding sleep from Montgomery-Åsberg Depression Rating Scale (MADRS).

Physical activity measured by an activity monitor, the Actigraph. Number of steps per day and number of activity counts per day will be measured.

Two indicator questions on physical activity from the Swedish National Board of Health and Welfare.

Oral glucose tolerance test (OGTT):blood glucose in mmol/l,

Lipid profile, measured by total cholesterol as well as separately as LDL- cholesterol and HDL-cholesterol. Unit of measure is mmol/l.

C-reactive protein (CRP) in blood sample, units of measure is mg/l.

Interleukins in blood sample, units of measure is pg/ml.

Insulin-like growth factor 1 (IGF-1), units of measure is pg/ml.

Brain-derived neurotrophic factor (BDNF), units of measure is pg/ml.

Blood pressure at rest, measured as systolic ans diastolic pressure in mmHg.

Resting heart rate, measured as beats per minute.

Heart rate variability (HRV), measured in the time domain (e.g. RMSSD) and frequency domain (LF:HF).

Attendance: number of sessions attended.

Absolute work-load during training in Watt.

Relative training intensity, as percentage of MAP (Maximum Aerobic Power output).

Relative training intensity, as percentage of MHR (maximum heart rate).

Perceived exertion during training, measured with the Borg Rating of perceived exertion scale (RPE)

Adverse events, discomfort or chest pain during training measured with the Borg Category ratio scale (CR-10).

Affective state during training session using Feeling Scale, range -5 to 5, higher score indicates better feeling.

Focus group interviews.