Relationships Between Aerobic Performance, Hemoglobin Levels, and Training Load During Small-Sided Games: A Study in Professional Soccer Players

Saeid Younesi; Alireza Rabbani; Filipe Manuel Clemente; Rui Silva; Hugo Sarmento; António José Figueiredo

doi:10.3389/fphys.2021.649870

Relationships Between Aerobic Performance, Hemoglobin Levels, and Training Load During Small-Sided Games: A Study in Professional Soccer Players

Front Physiol. 2021 Feb 16:12:649870. doi: 10.3389/fphys.2021.649870. eCollection 2021.

Authors

Saeid Younesi¹, Alireza Rabbani², Filipe Manuel Clemente^{3

4}, Rui Silva¹, Hugo Sarmento¹, António José Figueiredo¹

Affiliations

¹ University of Coimbra, Research Unit for Sport and Physical Activity, Faculty of Sport Sciences and Physical Education, Coimbra, Portugal.
² Department of Exercise Physiology, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran.
³ Escola Superior Desporto e Lazer, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun'Álvares, Viana do Castelo, Portugal.
⁴ Instituto de Telecomunicações, Delegação da Covilhã, Covilhã, Portugal.

Abstract

The purposes of this study were (1) to analyze between-session variations of external and internal load measures during small-sided games (SSGs) and (2) to test the relationships between the maximum speed reached (V_IFT) during the last stage of the 30-15 Intermittent Fitness Test, hemoglobin levels, and training load measures during SSG intervals among professional soccer players. Sixteen professional soccer players (mean ± SD; age 27.2 ± 3.4 years, height 174.2 ± 3.6 cm, body mass 69.1 ± 6.4 kg, and body fat 10.4 ± 4.1%) participated in this study. Hemoglobin and aerobic performance were first tested, and then a 3-week SSG program was applied using a 3 vs. 3 format. During those 3 weeks, internal and external load of entire sessions were also monitored for all training sessions. Trivial-to-small, standardized differences were observed between sessions for external and internal measures during SSGs. Total distance (TD) and mechanical work (MW) were the only variables that indicated small changes. Large-to-very-large relationships were found between V_IFT and external loads: TD (r range: 0.69; 0.87), high-intensity running (HIR; r range: 0.66; 0.75), and MW (r range: 0.56; 0.68). Moderate-to-large negative relationships were found between hemoglobin levels and internal loads: Edwards' TRIMP (r range: -0.36; -0.63), %HR_max (r range: -0.50; -0.61), and red zone (r range: -0.50; -0.61). V_IFT had unclear relationships with overall internal loads, while hemoglobin levels presented unclear relationships with overall external loads. In conclusion, no meaningful changes were found between sessions considering the format of play used. Additionally, the detected relationships indicate that V_IFT and hemoglobin levels are good indicators of the performance capacity and physiological profile of players during SSGs. Also, the use of SSGs protocols as a monitoring complement of the 30-15_IFT is suggested.

Keywords: SSGs; aerobic capacity; athletic performance; drill-based games; football (soccer); motor skills.