Moderate-Intensity Exercise and Pain Sensitization in Breast Cancer Survivors: A Case-Based Study

This variable captures tolerance-related indicators, including number of incomplete sessions. This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on tolerance.

This variable captures tolerance-related indicators, including number of sessions at moderate intensity. This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on tolerance.

This variable captures tolerance-related indicators, including number of participants completing at moderate intensity. This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on tolerance.

This variable captures tolerance-related indicators, including number of progressions during the program. This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on tolerance.

This variable captures tolerance-related indicators, including final progression level reached. This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on tolerance.

This variable aggregates motivation-related indicators, including number of absences.This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on motivation.

This variable aggregates motivation-related indicators, including percentage of sessions recovered after absence. This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on motivation.

This variable aggregates motivation-related indicators, including number of dropouts.This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on motivation.

This variable aggregates motivation-related indicators, including number of presence of positive sensations (e.g., satisfaction, motivation).This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on motivation.

This variable aggregates motivation-related indicators, including number of occurrence of adverse effects.This variable will be analyzed using contingency tables to evaluate therapeutic adherence based on motivation.

The BPI consists of 11 items: four assessing intensity and seven evaluating interference in areas such as general activity, mood, walking ability, work, relationships, sleep, and enjoyment of life. Scores range from 0 to 10, with higher scores indicating greater pain or interference. The BPI has demonstrated strong test-retest reliability (0.59-0.94), internal consistency in cancer populations (Cronbach's alpha 0.81-0.89), and construct validity across various demographic and clinical subgroups

Pain intensity was measured using the Numerical Rating Scale (NRS), which ranges from 0 ("no pain") to 10 ("worst imaginable pain"). This scale has shown high reproducibility in assessing pain exacerbations (Cohen's κ = 0.86) and overall pain intensity (Cohen's κ = 0.80)

A validated Spanish-language tool composed of seven yes/no items, with scores ranging from 0 to 24. A score of 12 or higher indicates a high probability of neuropathic pain, while a score below 12 suggests a low likelihood. The S-LANSS has demonstrated strong diagnostic properties, with 85% sensitivity and 80% specificity

Handgrip strength was assessed using a Jamar hydraulic dynamometer set to the second handle position. Participants performed three 5-second maximal isometric contractions per hand, with 30-second rests between attempts. The average of the three trials was used for analysis, starting with the non-operated side. Standardized verbal instructions and countdowns were given to ensure consistency.

Calibrated Von Frey monofilaments were applied perpendicularly to the skin until the filament just bent. Filament sizes were increased until the first sensation was detected, and the initial detectable filament was recorded. A descending series was then applied to identify the smallest filament still perceived. This ascending-descending method was repeated five times, and the method of limits was used to determine thresholds.

Standardized instructions: "With your eyes open, I will apply pressure using several filaments of varying stiffness. Some you may feel, others you may not. Then, with your eyes closed, please indicate each time you feel the stimulus. Close your eyes, and we will begin."

Mechanical pain threshold was assessed using Von Frey filaments. Filaments were applied in ascending order until the participant first reported the sensation as painful. Then, a descending sequence identified the smallest filament still perceived as painful. The test was repeated five times, and the mean filament force (measured in grams) was recorded as the MPT.

Standardized instructions: "You will feel a sharp stimulus. Please tell me when the sensation becomes uncomfortable but not yet painful-approximately 4 out of 10 on the Numerical Pain Rating Scale (NPRS), where 0 = no pain and 10 = worst imaginable pain. Higher filament force indicates a higher pain threshold (less sensitivity)."

Temporal summation was evaluated using Von Frey filaments at the mechanical pain threshold. A single stimulus was applied to a fixed point, followed by a pain rating on the NRS (, 0-10). Then, 10 identical stimuli were delivered at a frequency of 1 Hz using a 60- bpm metronome. A second NRS score was collected immediately after. The procedure was repeated three times, and the average was used for analysis.

Standardized instructions: "We will apply the same sharp stimulus used in the previous test. Please rate your pain intensity on a scale from 0 to 10, where 0 means no pain and 10 indicates the worst imaginable pain. Keep your eyes closed during the procedure. First, rate your pain after one stimulus, and then again after the sequence of ten."

Pressure pain threshold was measured using a digital algometer (Wagner Instruments FPX 100). With the patient in a supine position, incremental pressure was applied perpendicularly to the skin until pain was first perceived. Three measurements were obtained per site, and the average was used for analysis. Assessments were conducted at the primary painful area, the contralateral upper limb, and the anterior thigh of a pain-free lower limb.

A self-reported instrument developed by the World Health Organization and validated for use in cancer populations and Spanish-speaking individuals. The GPAQ evaluates physical activity in three domains-occupational, transportation, and leisure-and also captures sedentary behavior, defined as daily time spent sitting or lying down, excluding sleep. Based on total activity scores, participants were classified as inactive (<100), mildly active (100-1951), moderately active (1952-5724), or vigorously active (≥5725) (Cleland et al., 2014).

This 23-item questionnaire includes four functional scales (body image, sexual functioning, sexual enjoyment, and future perspective) and four symptom scales (side effects of therapy, breast symptoms, arm symptoms, and distress from hair loss). Responses are given on a 4-point Likert scale ranging from 0 ("not at all") to 4 ("very much")

Functional capacity was assessed using the Siconolfi Step Test, a validated submaximal test for estimating maximal oxygen uptake (VO₂max) in cancer populations. The test was performed on a 10-inch (25.4 cm) step in three 3-minute stages, with 1-minute rest intervals. Cadence was controlled via metronome at 68 bpm (stage 1), 104 bpm (stage 2), and 136 bpm (stage 3), corresponding to 17, 26, and 32 steps per minute, respectively. Heart rate was recorded at 2:30 minutes into each stage using a POLAR monitor. The test was terminated if participants experienced cardiorespiratory symptoms, musculoskeletal discomfort, peripheral fatigue, inability to maintain cadence, an RPE of 10, or if heart rate exceeded 65% of age-predicted maximum (220 - age).