Ramírez-Vélez R, Cruz-Salazar SM, Martínez M, Cadore EL, Alonso-Martinez AM, Correa-Bautista JE, Izquierdo M, Ortega FB, García-Hermoso A. Construct validity and test-retest reliability of the International Fitness Scale (IFIS) in Colombian children and adolescents aged 9-17.9 years: the FUPRECOL study. PeerJ 2017 May 23;5:e3351. doi: 10.7717/peerj.3351. eCollection 2017.


BACKGROUND: There is a lack of instruments and studies written in Spanish evaluating physical fitness, impeding the determination of the current status of this important health indicator in the Latin population, especially in Colombia. The aim of the study was two-fold: to examine the validity of the International Fitness Scale (IFIS) with a population-based sample of schoolchildren from Bogota, Colombia and to examine the reliability of the IFIS with children and adolescents from Engativa, Colombia. METHODS: The sample comprised 1,873 Colombian youths (54.5% girls) aged 9-17.9 years. We measured their adiposity markers (waist-to-height ratio, skinfold thickness, percentage of body fat and body mass index), blood pressure, lipids profile, fasting glucose, and physical fitness level (self-reported and measured). A validated cardiometabolic risk index score was also used. An age- and sex-matched subsample of 229 schoolchildren who were not originally included in the sample completed the IFIS twice for reliability purposes. RESULTS: Our data suggest that both measured and self-reported overall physical fitness levels were inversely associated with percentage of body fat indicators and the cardiometabolic risk index score. Overall, schoolchildren who self-reported "good" or "very good" fitness had better measured fitness levels than those who reported "very poor/poor" fitness (all p < 0.001). The test-retest reliability of the IFIS items was also good, with an average weighted kappa of 0.811. DISCUSSION: Our findings suggest that self-reported fitness, as assessed by the IFIS, is a valid, reliable, and health-related measure. Furthermore, it can be a good alternative for future use in large studies with Latin schoolchildren from Colombia.

Full Text

The full text is available at https://dx.doi.org/10.7717/peerj.3351

At A Glance

Individual Physical Activity Behavior Variables

Perceived Overall Fitness


Individual Physical Activity Behavior

Measure Type


Measure Availability

Free. Access at http://profith.ugr.es/IFIS

Number of Items

5 Reported

Study location


Bogota, Colombia



Information about Development of Measure

The International Fitness Scale (IFIS) was originally validated in nine European countries and languages in the HELENA study, but no study has evaluated the validity and reliability of the IFIS outside Europe, which is the goal of this study.

Study Design

Study Participants


6 - 11 Years

12 - 18 Years






Predominantly Low-income/Low-SES

Not reported

Sample Size


Study Design

Design Type


Health Outcomes Assessed


Obesity Measures

BMI for age

Percent body fat (Bioelectrical impedance analysis)

BMI Measured or Self-reported

Measured height

Measured weight


Not available

Data Reported on Race/Ethnicity

Quantitative data on study sample

Data Reported on SES

Not applicable

SES-related Variables

Not applicable

How To Use


Who Administered


How Administered


Time Required

Not reported

Training Required

Not reported

Instructions on Use

Instructions on instrument use included in article

Data Analysis

Data Collection/Analysis Costs

Not reported

Data Collection/Protocol

Schoolchildren included in the study were part of The Fuprecol Study. Self-reported fitness was assessed using the International Fitness Scale (IFIS). Cardiorespiratory fitness was assessed using the twenty minute shuttle run test. Musculoskeletal fitness (MF) was assessed using the standing broad jump and the handgrip strength test. Speed and agility were measured using the four times ten shuttle run test. Flexibility was measured using the standard sit-and-reach test. The test-retest study was conducted with a separate age-matched sample of children and adolescents who completed the IFIS on two occasions, one week apart.

Instructions on Data Analysis

Instructions on analysis included in article

Validity (1)

Type of validity Construct/subscale assessed Criterion measure used Test/statistic used Result
Criterion Self-reported physical fitness, International Fitness Scale (IFIS) Measured physical fitness Bonferroni-adjusted pairwise comparisons Participants with a high level of self-reported fitness (i.e., good and very good categories) had higher measured Cardiorespiratory fitness, Musculoskeletal fitnes, speed and agility, and flexibility compared to schoolchildren reporting very poor/poor fitness level (all p < 0.001)

Reliability (1)

Type of reliability Construct/subscale assessed Test/statistic used Result
Test-retest International Fitness Scale (IFIS) components Cronbach's alpha Kappa statistics Alpha = 0.733 to 0.789; Kappa = 0.775 to 0.847