Lifestyle Intervention Program for Former Elite Athletes

To estimate total FM, dual energy X-ray absorptiometry (Hologic Explorer-W, Waltham, USA) will be used. A whole-body scan will be performed and the attenuation of X-rays pulsed between 70 and 140 kV synchronously with the line frequency for each pixel of the scanned image will be measured.

Total abdominal FM by identifying a specific region of interest (ROI) within the analysis programme.

Specific DXA ROIs for abdominal regional fat will be defined as follows: ROI 1, the upper edge of the second lumbar vertebra (approximately 10 cm above the L4 to L5) to above the iliac crest and laterally encompasses the entire breadth of the abdomen, thus determining total abdominal fat mass.

Subjects will have their weight measured (in kilograms) wearing a bathing suit to the nearest 0.01 kg with a weight scale (Seca, Hamburg, Germany)

Subjects will have their height measured (in meters) without shoes to the nearest 0.1 cm with a stadiometer (Seca, Hamburg, Germany).

Weight (in kilograms) and height (in meters) will be combined to report BMI in kg/m^2.

Subjects will have their. Waist circumference will be measured immediately above the iliac crest. Hip circumference will be assessed is determined at the maximum perimeter of the hips. Arm and thigh circumferences will be assessed at the level of the skinfold measurement. Calf circumference will be assessed at the at the maximum perimeter of the calf. Circumference measurements are performed twice and the arithmetic mean of both values is considered as the final value.

Maximal oxygen uptake (VO2max) capacity will be assessed using the Bruce maximal exercise test protocol performed on a variable speed and incline treadmill (Quinton Treadmill, Model 640, 90TM Series). VO2max is achieved when at least 2 of the following 3 criteria are obtained: a heart rate at or above the age-predicted maximum, and/or a respiratory exchange ratio greater than 1, and/or no increase in VO2max despite further grade increases.

Three measurements of systolic blood pressure are obtained with the participant in the sitting position using a digital sphygmomanometer. The blood pressure cuff-fixed on the nondominant upper arm is loosened during the two minutes pause between the measurements. The arithmetic means of the second and third reading are considered as the participants' blood pressure and pulse values, respectively. Overall, there is a rest of approximately five minutes before the second blood pressure measurement is carried out

Three measurements of diastolic blood pressure are obtained with the participant in the sitting position using a digital sphygmomanometer. The blood pressure cuff-fixed on the nondominant upper arm is loosened during the two minutes pause between the measurements. The arithmetic means of the second and third reading are considered as the participants' blood pressure. Overall, there is a rest of approximately five minutes before the second blood pressure measurement is carried out

Blood glucose levels will be performed in serum samples using coloured enzymatic tests, in an automated analyser (Cobas Integra 400).

Blood lipid profile, including total cholesterol, high density lipoprotein cholesterol (HDL) will be performed in serum samples using coloured enzymatic tests, in an automated analyser (Cobas Integra 400).

Blood insulin levels assessment will be performed in an automated analyser (Cobas Integra 400) by eletroquimioluminescence.

Blood thyroid panel (T3, T4, TSH) will be run by immunoassay with chemiluminescent detection (Millipore Corp., Billerica, MA).

Serum levels of leptin will be measured by ELISA.

One repetition leg press maximum test (1RM) that measure the maximal weight a subject can lift with one repetition will be used. Before each assessment the participant will be instructed to conduct a 5min warmup period, preceded by a respective familiarization period with the specific test for the lower limb. The evaluation of the maximum strength of the leg will be made by performing a horizontal leg press isometric test (S0409, BPH) with the bent leg and the knee joint at an angle of 110 °. Participants will complete 5 maximal voluntary repetitions lasting 34 seconds, and a period of rest between reps 60s. All participants will be asked to produce strength the fastest possible in all repetitions. The Plux software (Biosignalsplux) will be considered to analyze the highest value between the maximal voluntary repetitions.

Handgrip strength test evaluates maximal isometric force of the forearm muscle and will be assessed by a portable hand dynamometer JAMAR plus digital (Sammons Preston, Bolingbrook, IL). Participants will be assessed on both hands alternately. Prior to the test, the grip dynamometer will be adjusted to the size of the hand of each subject. Each participant will be assessed on both hands alternately until add up three attempts for each hand. In each attempt the subject will exert the maximal grip strength on the handgrip dynamometer with the assessed hand during 5 seconds. After each attempt there will be a resting period of 60 seconds that will be used both for recovery and for changing the handgrip dynamometer to the opposite hand.

The reward value of food (i.e., implicit wanting/explicit liking and wanting) will be measured by a computer procedure, the Leeds Food Preference Questionnaire (LFPQ) [38, 39], which uses a 'forced choice' reaction time measure of implicit wanting in addition to explicit subjective measures of liking and wanting for visual food stimuli varying in fat content and taste. Implicit wanting is operationalized as the reaction time of each pair trial decision. Thus, the speed with which one category of stimuli is chosen relative to alternative categories provides a quantifiable measure of implicit wanting for each food category in the procedure.

The Behavioral Regulation in Exercise Questionnaire - 3 (BREQ-3) will be used to assess motivations to engage in exercise. BREQ-3 contains 24 items, organized into 6 subscales, measuring amotivation, external, introjected (i.e controlled motivational regulations), identified, integrated, and intrinsic motivations (i.e autonomous motivational regulations). Following the stem "why do you exercise", participants respond on a 5-point Likert scale ranging from 0 ("not true for me") to 4 ("very true for me"). Prior research has supported BREQ's factor structure and reliability (Cronbach's alphas > 0.70).

Whole body R (Ω) and Xc (Ω) will be assessed by Bioelectrical impedance spectroscopy analysis (model 4200B; Xitron Technologies, San Diego, CA, USA) and by a single-frequency BIA, phase-sensitive 50 kHz (BIA-101, RJL/Akern Systems, Firenze, Italy).

Before the test, subjects were instructed to lie in a supine position with their arms and legs abducted at a 458 angle for 10 min. This impedance spectra was modelled with the Cole-Cole cell suspension model to derive a theoretical impedance at zero and infinity frequency, based on a non-linear curve fitting from the measured resistance and reactance.

Phase angle (º) will be assessed by Bioelectrical impedance spectroscopy analysis (model 4200B; Xitron Technologies, San Diego, CA, USA). Before the test, subjects were instructed to lie in a supine position with their arms and legs abducted at a 458 angle for 10 min. This impedance spectra was modelled with the Cole-Cole cell suspension model to derive a theoretical impedance at zero and infinity frequency, based on a non-linear curve fitting from the measured resistance and reactance. The frequency 50 kHz will be used for phase angle analysis.

Intracellular water and extracellular water were predicted from the Hanai mixture theory, and TBW was estimated by the sum of intracellular water and extracellular water. Considering ten repeated measures, the TEM and CV for TBW were 0·47 litres and 1·1% respectively.

Food records will also be collected to characterize macronutrient composition of the diet in the 3 moments using a software package (Food Processor SQL, ESHA Research, Salem, OR, USA).

When total energy expenditure (TEE) is obtained in conjunction with measured body composition, then two terms of the energy balance equation are known, namely ES and EE. From equation 1 it is possible to solve for average energy intake during the course of the study.

The magnitude of compensation will be calculated as the difference between achieved energy imbalance and energy expenditure.

The amount of activity assessed by the Actigraph accelerometer will be expressed as minutes per day spent in different intensities. The cutoff values used to define the intensity of PA and therefore to quantify the mean time in each intensity (sedentary, light, moderate or vigorous) will be: sedentary: < 100 counts·min-1; light: 100-2019 counts·min-1; moderate: 2020-5998 counts·min-1 (corresponding to 3-5.9 METs); vigorous: ≥ 5999 counts·min-1 (corresponding to ≥6 METs). The Actiheart (Actiheart, CamNtech Limited, UK) is a lightweight (10 g) combined heart rate (HR) and movement (uniaxial accelerometer oriented to measure acceleration along the body's longitudinal axis) sensor that utilizes both piezoelectric accelerometer and HR data synchronously. Participants will wear the Actiheart 24h day-1 at the same time as the accelerometer and a valid day will be defined as having 600 or more minutes (≥10h) of monitor wear during waking hours.

Total energy expenditure will be assessed by the Actigraph accelerometer using the Crouter et al equations.

Physical activity energy expenditure (PAEE) will be calculated as total energy expenditure (TEE) minus (0.1*TEE + REE), assuming the termic effect of food represents 10% of TEE, and REE represents Resting energy expenditure.

In order to predict resting energy expenditure (REE) at baseline, a gender specific regression equation using FFM and FM as the independent predictor will be generated. This equation will then be used to predict REE at 3 and after a 9-month follow-up, using the measured values of FM and FFM at these time points. To disclose any adaptations in REE not accounted for by changes in FFM, adaptive response will be assessed as 1 minus the ratio between the actual to the expected/predicted REE, multiplied by 100. Positive values indicate a decrease in REE beyond that expected by changes in body composition (actual REE below predicted REE) whereas negative values represent a change in REE equal to or greater than the predicted REE (actual REE higher than predicted REE).

The MedGraphics CPX Ultima (MedGraphics Corporation, Breezeex Software) indirect calorimeter will be used to measure breath-by-breath oxygen consumption (V̇O2 ) and carbon dioxide production (V̇CO2) using a facial mask. The oxygen and carbon dioxide analyzers will be calibrated in the morning before testing using known gas concentration. Before testing, participants will be instructed about all the procedures and asked to relax, breathe normally, not to sleep, and not to talk during the evaluation. Total rest duration will be 45 minutes, participants lied supine for 15 minutes covered with a blanket and the calorimeter device will then be attached to the mask and breath by breath V̇O2 and V̇CO2 will be measured for 30 min period.

The mean V̇O2 and V̇CO2 of 5 min steady states will be used in Weir equation and the period with the lowest REE will be considered for data analysis.

To measure general health-related quality of life, participants will complete the Short-Form Health Survey (SF-36) questionnaire [45], with a total of 36 items composed of eight dimensions: Physical functioning (Cronbach's a = .83), physical role limitations (Cronbach's a = .89), bodily pain (Cronbach's a = .88), general health (Cronbach's a = .82), emotional role limitations (Cronbach's a = .74), social functioning (Cronbach's a = .71), vitality (Cronbach's a = .86), and mental health (Cronbach's a = .90). Higher scores indicate better health-related quality of life.