Dmax method estimates lactate threshold in individuals with type 2 diabetes

• Published in: Sport sciences for health Vol. 12; no. 2; pp. 175 - 181
• Main Authors: da Silva Aguiar, Samuel, de Sousa, Caio Victor, Sales, Marcelo Magalhães, Filho, José Morais Souto, da Costa Sotero, Rafael, dos Santos Rosa, Thiago, Simões, Herbert Gustavo
• Format: Journal Article
• Language: English
• Published: Milan Springer Milan 01.08.2016; Springer Nature B.V
• Subjects: Acidosis; Aerobics; Anaerobic threshold; Body fat; Diabetes; Exercise intensity; Gases; Hemoglobin; Human Physiology; Medicine; Medicine & Public Health; Metabolic Diseases; Metabolism; Methods; Original Article; Physical fitness; Physiology; Sports Medicine; Incremental exercise test; Anaerobic threshold; Reliability; O
• ISSN: 1824-7490; 1825-1234
• DOI: 10.1007/s11332-016-0272-2

While several studies have identified the lactate threshold (LT) through the visual method, others have suggested the application of mathematical models, such as Dmax . However, its validity has not yet been investigated in individuals with type 2 diabetes (T2D). The purpose of this study was to compare and analyze the relationship between variables of internal and external load at LT identified by the visual and Dmax methods in T2D individuals. Seven T2D (62.2 years, 71.6 kg, 26.4 kg m −2 ) and nine non-diabetics (ND) individuals (59.7 years, 68.2 kg, 26.4 kg m −2 ) underwent an incremental exercise test on a cycle ergometer. Heart rate (HR), blood lactate and expired gas concentrations were measured at the end of each stage. The visual LT was considered an exercise intensity above which an over proportional increase in blood lactate was observed in relation to increasing workload. Dmax point was objectively identified on the lactate regression curve that yielded the higher distance to the straight line formed between the first and the last point of the curve. The results indicates no statistical differences between the visual and Dmax methods, respectively, for the workload (68.5 ± 28.1 vs. 53.6 ± 22.7), HR (129.4 ± 12.2 vs. 133.1 ± 18.3) and V O 2 (14.3 ± 3 vs. 14.3 ± 2.5) corresponding to the LT for T2D. As well as no differences were identified for the ND group for workload (70.2 ± 18.9 vs. 65 ± 30.9), HR (124.3 ± 19.5 vs. 124.3 ± 17.3) and V O 2 (15.8 ± 2.5 vs. 16.4 ± 4.4). We conclude that the Dmax could be easily determined during incremental exercise in both T2D and controls and apparently do occurs at intensities related to LT.