Patients of both genders aged 18 to 59 years were included in the study. They had been
diagnosed with COVID-19 in the past year, experienced mild or moderate symptoms, had
shortness of breath, were either sedentary or engaged in physical exercise at least twice
a week, and agreed to sign the Informed Consent Form. Excluded from the study were
individuals hospitalized due to COVID-19, those diagnosed with chronic lung diseases,
smokers, those who had undergone prior physiotherapeutic treatment for post-COVID-19
syndrome, individuals with a history of lower limb surgeries or fractures (within the
last six months), BMI over 30 kg/m², and those with neurological, cognitive, or cardiac
impairments.

The sample, selected for convenience, was divided into two distinct groups: the global
muscle strengthening group (GF) and the low-intensity aerobic training associated with
global muscle strengthening group (GAF). The GF comprised eight volunteers, while the GAF
had nine, totaling eight sessions with a frequency of two interventions per week, lasting
30 minutes each for the GF and 60 minutes each for the GAF. Two assessments were
conducted: one at admission and another at the end of the treatment.

Participants were recruited at the Dr. Cícero Brandon School Clinic of Faculty President
Antônio Carlos in Ubá city, state of Minas Gerais, with authorization for data collection
and infrastructure use signed by the study researchers and supervisor. Volunteers were
assessed during the first session to ensure compliance with inclusion and exclusion
criteria outlined in the medical history form. They were informed about the entire
procedure and study objectives and subsequently guided to sign the Informed Consent Form,
following Resolution 466/2012 of the National Health Council.

Body Mass Index (BMI) calculation was done using a Multilaser digital scale and a
two-meter measuring tape. Quality of life was assessed using the abbreviated version of
the WHOQOL-100, the WHOQOL-bref, consisting of 26 questions related to general quality of
life, satisfaction with one's health, and domains of physical, psychological, social
relationships, and the environment.

Aerobic capacity was evaluated through the Six-Minute Walk Test (6MWT), performed on a
flat, obstacle-free 30-meter track. The objective was to analyze the farthest distance a
patient could walk in six minutes without running, with the option to stop at any time
without interrupting the timing. Standardized encouragement phrases were used every
minute during the test.

The Medical Research Council (MRC) Dyspnea Scale was used to categorize the degree of
dyspnea, with patients choosing an item corresponding to the proportion of limitation
caused by dyspnea in their daily activities. Muscle strength measurement was conducted
for each volunteer using a validated digital scale in the quadriceps (90° knee flexion),
hamstrings (90° knee flexion), biceps brachii (90° elbow flexion), triceps brachii
(anatomical position), and deltoid (midportion, 30° shoulder abduction).

Blood pressure, heart rate, and oxygen saturation were measured at the beginning and end
of each session using a premium brand sphygmomanometer and stethoscope, a G-tech pulse
oximeter, and assessed throughout the session. Difficulty levels in performing proposed
activities, considering peripheral musculature, were queried using the Borg Scale.

The GF group focused on exercises for strengthening hip adductor muscles associated with
bridge exercises using a small exercise ball, hamstring strengthening with ankle weights
in prone position, bilateral hip flexor strengthening in supine position with ankle
weights, bilateral shoulder flexor strengthening with dumbbells, bilateral shoulder
extensor strengthening with dumbbells, bilateral shoulder abductor strengthening with
dumbbells, and bilateral serratus anterior muscle strengthening with dumbbells (all
exercises except the first in three sets of 10 repetitions). Progression was based on
each patient's development.

The GAF protocol initially involved a five-minute warm-up, consisting of two minutes of
stationary marching and three minutes of jumping jacks. Patients were then instructed to
climb up and down ramps, ascend and descend stairs, walk on a flat surface, and use a
cycle ergometer (each task performed for five minutes). For the recovery phase, bilateral
stretching of hamstrings, rectus femoris, triceps brachii, pectoralis major,
sternocleidomastoid, and scalene muscles was performed, each lasting 30 seconds. This
protocol was associated with the anaerobic training described in the GF.

Volunteers were allocated to two groups using a simple random sampling method with two
blocks. Results were placed in sealed envelopes, concealing the patient allocation
sequence from the researcher.