What Mathematical Models Are Accurate for Prescribing Aerobic Exercise in Women with Fibromyalgia?

Santos Villafaina; Clarissa Biehl-Printes; José A Parraca; Fabiane de Oliveira Brauner; Pablo Tomas-Carus

doi:10.3390/biology11050704

What Mathematical Models Are Accurate for Prescribing Aerobic Exercise in Women with Fibromyalgia?

Biology (Basel). 2022 May 4;11(5):704. doi: 10.3390/biology11050704.

Authors

Santos Villafaina^{1

2}, Clarissa Biehl-Printes³, José A Parraca^{2

4}, Fabiane de Oliveira Brauner³, Pablo Tomas-Carus^{2

4}

Affiliations

¹ Facultad de Ciencias del Deporte, Universidad de Extremadura, Avenida de la Universidad s/n, 10003 Caceres, Spain.
² Departamento de Desporto e Saúde, Escola de Saúde e Desenvolvimento Humano, Universidade de Évora, 7004-516 Evora, Portugal.
³ Instituto de Geriatria e Gerontologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre 6681, Brazil.
⁴ Comprehensive Health Research Centre (CHRC), University of Évora, 7005 Evora, Portugal.

Abstract

Objectives: This article aims to verify the agreement between the standard method to determine the heart rate achieved in the ventilatory threshold 1 in the cardiopulmonary exercise testing (VT1) and the mathematical models with exercise intensities suggested by the literature in order to check the most precise for fibromyalgia (FM) patients.

Methods: Seventeen women with FM were included in this study. The VT1 was used as the standard method to compare four mathematical models applied in the literature to calculate the exercise intensity in FM patients: the well-known "220 - age" at 76%, Tanaka predictive equation "208 - 0.7 × age" at 76%, the FM model HRMax "209 - 0.85 × age" at 76%, and Karvonen Formula at 60%. Bland-Altman analysis and correlation analyses were used to explore agreement and correlation between the standard method and the mathematical models.

Results: Significant correlations between the heart rate at the VT1 and the four mathematical estimation models were observed. However, the Bland-Altman analysis only showed agreement between VT1 and "220 - age" (bias = -114.83 + 0.868 × x; 95% LOA = -114.83 + 0.868 × x + 1.96 × 7.46 to -114.83 + 0.868 × x - 1.96 × 7.46, where x is the average between the heart rate obtained in the CPET at VT1 and "220 - age", in this case 129.15; p = 0.519) and "209 - 0.85 × age"(bias = -129.58 + 1.024 × x; 95% LOA = -129.58 + 1.024 × x + 1.96 × 6.619 to -129.58 + 1.024 × x - 1.96 × 6.619, where x is the average between the heart rate obtained in the CPET at VT1 and "209 - 0.85 × age", in this case 127.30; p = 0.403).

Conclusions: The well-known predictive equation "220 - age" and the FM model HRMax ("209 - 0.85 × age") showed agreement with the standard method (VT1), revealing that it is a precise model to calculate the exercise intensity in sedentary FM patients. However, proportional bias has been detected in all the mathematical models, with a higher heart rate obtained in CPET than obtained in the mathematical model. The chronotropic incompetence observed in people with FM (inability to increase heart rate with increasing exercise intensities) could explain why methods that tend to underestimate the HRmax in the general population fit better in this population.

Keywords: cardiopulmonary exercise testing; chronic pain; heart rate; physical activity; predictive equations.

Grants and funding

This study benefited from the support of the UÉvora—UniverCIDADE VII program. Portuguese Institute for Sportand Youth—I.P., Support for Sport Activity 2022, Sport Development Program Agreement, CP/DD/2022. The author SV was supported by a grant from the Universities Ministry of Spain and the European Union (NextGenerationUE) “Ayuda del Programa de Recualificación del Sistema Universitario Español, Modalidad de ayudas Margarita Salas para la formación de jóvenes doctores” (MS-03).