Self-reported (IFIS) versus measured physical fitness, and their associations to cardiometabolic risk factors in early pregnancy

Maria Henström,Francisco B Ortega,Pontus Henriksson,Emmie Söderström,Marie Löf,Johanna Sandborg,Marja H Leppänen

doi:10.1038/s41598-021-02149-7

Abstract

Physical fitness is a strong marker of health, but objective fitness measurements are not always feasible. The International FItness Scale (IFIS) for self-reported fitness is a simple-to-use tool with demonstrated validity and reliability; however, validation in pregnancy needs to be confirmed. Also, its association with cardiometabolic health in pregnant women is unknown. Hence, we examined (1) the validity of the IFIS with objectively measured fitness, and (2) the associations of self-reported versus objectively measured cardiorespiratory fitness (CRF) and muscular strength with cardiometabolic risk factors in early pregnancy. Women (n = 303) from the HealthyMoms trial were measured at gestational week 14 for: CRF (6-min walk test); upper-body muscular strength (handgrip strength test); self-reported fitness (IFIS), body composition (air-displacement plethysmography); blood pressure and metabolic parameters (lipids, glucose, insulin). Higher self-reported fitness was associated with better measured fitness (ANOVA overall p < 0.01 for all fitness types), indicating the usefulness of the IFIS in pregnancy. Furthermore, higher self-reported overall fitness and CRF were associated with lower cardiometabolic risk scores (ANOVA p < 0.001), with similar results shown for measured CRF (ANOVA p < 0.001). The findings suggest that IFIS could be useful to stratify pregnant women in appropriate fitness levels on a population-based level where objective measurement is not possible.

Highlights

Physical fitness is a powerful marker of health
Our findings support the usefulness of the International FItness Scale (IFIS) in early pregnancy, as women in the study who reported higher physical fitness had significantly better measured fitness levels on a group level compared to women reporting lower fitness
IFIS provides concordant associations with cardiometabolic risk factors compared to associations based on objectively measured physical fitness

Summary

Introduction

Physical fitness is a powerful marker of health. Cardiorespiratory fitness (CRF) has been considered as an indicator of cardiometabolic health status in both children and a dults[1,2], and greater muscular strength in adults has been related to better h ealth[3]. In pregnant women, improved physical fitness has been associated with better neonatal outcomes and decreased risk of caesarean section[4] as well as with less bodily pain and reduced pain d isability[5]. Accurate and feasible measures of physical fitness during pregnancy is essential in epidemiological and public health research. Since pregnancy is characterized by weight gain as well as other physiological and biochemical changes[6], this may hinder objective measurement of physical fitness. There is a need for alternative methods that can accurately assess physical fitness in cases where objective measuring is not possible

Objectives

Methods

Results

Conclusion