The Role of Aerobic Training Variables Progression on Glycemic Control of Patients with Type 2 Diabetes: a Systematic Review with Meta-analysis.

BACKGROUND: Aerobic training (AT) improves glycemic control in patients with type 2 diabetes. However, the role of the progression of training variables remains unclear. The objective of this review was to analyze the effects of progressive AT (PAT) and non-progressive AT (NPAT) on glycated hemoglobin (HbA1c) in patients with type 2 diabetes. METHODS: Data sources used were PubMed, Cochrane Central, Embase, SPORTDiscus, and LILACS. Studies that evaluated the effect of at least 12 weeks of PAT and NPAT compared to a control condition on HbA1c levels in type 2 diabetes patients were eligible for analysis. Two independent reviewers screened the search results, extracted the data, and assessed the risk of bias. Effect sizes (ESs) were calculated using the standardized mean difference in HbA1c levels between the intervention and control groups using a random-effect model. RESULTS: Of 5848 articles retrieved, 24 randomized clinical trials (825 participants) were included. Among the included studies, 92% reported to have performed a randomization process, 8% presented allocation concealment, 21% reported blinding of outcome assessment, and 38% reported complete outcome data. AT reduced HbA1c levels by 0.65% (ES: - 1.037; 95% confidence interval [CI]: - 1.386, - 0.688; p < 0.001). The reduction in HbA1c induced by PAT was 0.84% (ES: - 1.478; 95% CI - 2.197, - 0.759; p < 0.001), and NPAT was 0.45% (ES: - 0.920; 95% CI - 1.329, - 0.512; p < 0.001). Subgroup analysis of the different forms of progression showed a reduction in HbA1c levels of 0.94% (ES: - 1.967; 95% CI - 3.783, - 0.151; p = 0.034) with progression in volume, 0.41% (ES: - 1.277; 95% CI - 2.499, - 0.056; p = 0.040) with progression in intensity, and 1.27% (ES: - 1.422; 95% CI - 2.544, - 0.300; p = 0.013) with progression in both volume and intensity. Subgroup analysis of the different modalities of AT showed a reduction of 0.69% (ES: - 1.078; 95% CI - 1.817, - 0.340; p = 0.004) with walking and/or running and of 1.12% (ES: - 2.614; 95% CI - 4.206, - 1.022; p = 0.001) with mixed protocols while progressive training was adopted. In non-progressive protocols, a significant HbA1c reduction was only found with walking and/or running (- 0.43%; ES: - 1.292; 95% CI - 1.856, - 0.72; p < 0.001). CONCLUSION: The effect of PAT on glycemic control was greater than that of NPAT, especially when volume and intensity were progressively incremented throughout the interventions.

Acute and chronic glycemic effects of aerobic training in patients with type 2 diabetes / Efeitos glicêmicos agudos e crônicos do treinamento aeróbio em pacientes com diabetes tipo 2

The aim of the present study was to analyze acute glycemic effects in different moments of an aerobic training, as well as to analyze the chronic effect of training, in patients with type 2 diabetes mellitus (T2D). The participants performed 16 weeks of interval aerobic training with three weekly sessions. The main part of each session consisted of nine blocks of five minutes, in which four minutes consist-ed of stimulus between 85% and 95% of the anaerobic threshold heart rate (ATHR) and one minute consisted of recovery below 85% of the ATHR, totalizing 45 minutes. Capillary glucose was assessed before, immediately after and 30 minutes after the first and the last training sessions. Glycated hemoglobin (HbA1c) was assessed before and after the intervention. Paired t-test and Generalized Estimating Equations were performed for the analyses; α = 5%. The participants were seven individ-uals (four women) aged 59.60 ± 6.69 years. In the first session, glucose values immediately after and 30 minutes after exercise were lower than pre-exercise values. On the other hand, in the last training session, only the glucose values immediately after exercise were lower than pre-exercise values. Ana-lyzing the glycemic reductions, the first session presented a greater reduction immediately after (p = 0.042) and 30 minutes after exercise (p = 0.010). Regarding chronic glycemic effects, an increase (p = 0.010) in HbA1c levels was observed after training. It is concluded that, after 16 weeks of training without progression of duration and intensity, the exercise loses its acute glycemic effect, and may be even insufficient to reduce HbA1c levels

O objetivo do estudo foi analisar os efeitos glicêmicos agudos em diferentes momentos de um treinamento aeróbio, bem como o efeito glicêmico crônico deste treinamento, em pacientes com diabetes tipo 2 (DM2). Os participantes realizaram16 semanas de treinamento aeróbio intervalado, com três sessões semanais, sendo a parte principal de cada sessão composta de nove blocos de cinco minutos, tendo cada bloco quatro minutos de estímulo a 85% a 90% da frequência cardíaca referente ao limiar anaeróbio (FCLAN) e um minuto de recu-peração abaixo de 85% da FCLAN, totalizando 45 minutos. A glicemia capilar foi avaliada antes, imediata-mente e 30 minutos após a primeira e a última sessão de treinamento. A hemoglobina glicada (HbA1c) foi avaliada antes e após a intervenção. Teste t pareado e Equações de Estimativas Generalizadas foram usados para as análises; α = 5%. Participaram sete indivíduos (59,60 ± 6,69 anos; quatro mulheres). Na primeira sessão, os valores glicêmicos imediatamente e 30 minutos após o exercício foram menores que os valores pré--exercício. Já na última sessão de treinamento, somente os valores glicêmicos imediatamente após o exercício foram menores que os valores pré-exercício. Analisando as reduções glicêmicas, a primeira sessão apresentou maior redução tanto imediatamente após (p = 0,042) como 30 minutos após o exercício (p = 0,027). Em relação ao efeito glicêmico crônico, observou-se aumento (p = 0,010) dos níveis de HbA1c após o treinamento. Conclui-se que após 16 semanas de treinamento sem progressão de duração e intensidade, o exercício perde efeito glicêmico agudo, podendo inclusive ser ineficiente na redução dos níveis de HbA1c

Acute glycemic and pressure responses of continuous and interval aerobic exercise in patients with type 2 diabetes.

BACKGROUND: Aerobic training has been widely indicated to patients with type 2 diabetes. However, there are still few studies comparing acute glycemic and blood pressure effects of different methods of aerobic training. The aim is to compare glycemic and pressure acute responses of continuous aerobic exercise to interval aerobic exercise in patients with type 2 diabetes. MATERIALS AND METHODS: This study is a randomized, crossover clinical trial. Fourteen patients with type 2 diabetes performed two sessions of aerobic training with different methods (continuous and interval). Continuous session had duration of 35 minutes with intensity of 85-90% of heart rate corresponding to anaerobic threshold (HRAT), while interval session had 45 minutes, with stimulus in intensity of 85-90% of HRAT with recovery in intensity under 85% of HRAT. Capillary glycemia, systolic and diastolic blood pressure were analyzed before and after the sessions. RESULTS: Patients were 63.5 ± 9.8 years old. Glycemia was reduced in both sessions (p < 0.001). Only glycemia measured at 25 minutes after continuous session was not lower than pre-session values. Systolic blood pressure was also reduced in both sessions (p = 0.010) with similar behavior between them. In the diastolic blood pressure, there were differences only between the values measured immediately after exercise and the values measured 20 minutes (p = 0.002) and 30 minutes after exercise (p = 0.008). CONCLUSION: Both continuous and interval aerobic exercise, in a same intensity, are effective for glycemic and pressure acute reductions in individuals with type 2 diabetes. For patients with greater risk of hypertension, we believe that the interval method is safer.

Effects of aerobic, resistance, and combined exercise training on insulin resistance markers in overweight or obese children and adolescents: A systematic review and meta-analysis.

OBJECTIVE: To assess the associations of aerobic, resistance, and combined exercise with changes in insulin resistance, fasting glucose, and fasting insulin in children and adolescents who are overweight or obese. DATA SEARCHES: MEDLINE via Pubmed, Cochrane-CENTRAL, SPORTDiscus, and LILACS. STUDY SELECTION: Randomized clinical trials of at least six weeks of duration that evaluated the ability of exercise training to lower at least one of the following outcomes: insulin resistance-HOMA, fasting glucose, and fasting insulin in children and/or adolescents classified as obese or overweight. DATA EXTRACTION AND ANALYSIS: Two independent reviewers extracted data and assessed the quality of the included studies. Differences (exercise training group minus control group) in the outcomes evaluated were analyzed using a random effects model. RESULTS: Of 1853 articles retrieved, 17 studies were included. The meta-analysis showed that physical training in general was not associated with a reduction in fasting glucose levels compared to the control, but it was associated with reductions in fasting insulin levels (-3.37µU/ml; CI 95%, -5.16µU/ml to -1.57µU/ml; I2, 54%, p=0.003) and HOMA (-0.61; CI 95%, -1.19 to -0.02; I2, 49%, p=0.040). In addition, each modality (aerobic, resistance, and combined) was compared to the control group. Aerobic exercise was associated with declines in fasting insulin levels (-4.52µU/ml; CI 95%, -7.40 to -1.65; I2, 65%, p=0.002) and in HOMA (-1.33; 95% confidence interval, -2.47 to -0.18; I2, 73%, p=0.005). CONCLUSIONS: Exercise training, especially aerobic training, is associated with the reduction of fasting insulin levels and HOMA in children and adolescents with obesity and overweight, and may prevent metabolic syndrome and type 2 diabetes.

Acute glycemic outcomes along the aerobic training in deep water in patients with type 2 diabetes / Respuestas de la glucemia aguda a lo largo del entrenamiento aeróbico en aguas profundas en pacientes con diabetes tipo 2

Aims: The present study aimed to analyze the acute glucose responses in the first and last sessions of four mesocycles along an aquatic aerobic training periodization. Methods: Fourteen patients (6 men and 8 women; 54.3 ± 9.0 years; body mass index of 34.5 ± 3.9 kg/m2) with type 2 diabetes underwent a 12-week training program involving deep-water running. This exercise training was performed by an interval training method, with a frequency of 3 times a week, session duration of 35 minutes and intensity progressing from 85 to 90% to 95 to 100% of the anaerobic threshold heart rate (ATHR) along the periodization. Capillary glucose was assessed before and immediately after the first and last session of each mesocycle. A generalized estimated equation (time x session x mesocycle) was used to assess reductions in glucose levels in different sessions (first and last) along four mesocycles (α = 0.05). Results: All sessions resulted in a reduction in glucose levels (time effect: p <0.001), without differences between the first and last session of each mesocycle (session effect: p = 0.738). With regard to the mesocycles (mesocycle effect: p = 0.003), significant differences were found between mesocycles 2 and 3. In time mesocycle interaction (p = 0.002), in most comparisons, post-session values were lowest that pre-session values, regardless of mesocycle, except for the post-session value of mesocycle 3, which was similar to the pre-values of mesocycles 2 and 4. Conclusion: Aerobic training in deep water with crescent linear periodization over 12 weeks is able to reduce glucose levels in patients with type 2 diabetes

Objetivo: Analizar las respuestas de glucemia aguda en las primeras y últimas sesiones de cuatro mesociclos a lo largo de una periodización de entrenamiento aeróbico acuático. Métodos: Catorce pacientes (6 hombres y 8 mujeres; 54,3 ± 9,0 años; índice de masa corporal de 34,5 ± 3,9 kg/m2) con diabetes tipo 2 fueron sometidos a un programa de entrenamiento de 12 semanas de carrera en aguas profundas. Se realizó un entrenamiento aeróbico de intervalos, realizado 3 veces por semana, con sesiones de 35 minutos y la intensidad progresando a lo largo de la periodización desde 85% - 90% a 95% - 100% de la frecuencia cardiaca del umbral anaeróbico (FCUA). La glucosa capilar fue evaluada antes e inmediatamente después de la primera y la última sesión de cada mesociclo. Se utilizó una ecuación generalizada estimada (tiempo x sesión x mesociclo) para evaluar las reducciones en los niveles de glucosa en las diferentes sesiones (primera y última) a lo largo de cuatro mesociclos (α = 0.05). Resultados: todas las sesiones resultaran en una reducción en los niveles de glucosa (efecto tiempo: p<0,001), sin diferencias entre la primera y la última sesión de cada mesociclo (efecto de sesión: p = 0,738). Con respecto a los mesociclos (efecto mesociclo: p=0,003) se encontraron diferencias significativas entre los mesociclos 2 y 3. En la interacción tiempo mesociclo (p=0,002), en la mayor.a de las comparaciones, los valores post-sesión fueron menores de los valores pre-sesión, independientemente de mesociclo, excepto para el valor después de la sesión del mesociclo 3, que fue similar a los valores antes de la sesión de los mesociclos 2 y 4. Conclusión: Doce semanas de entrenamiento aeróbico en aguas profundas con la periodización linear y creciente es capaz de reducir los niveles de glucosa en pacientes con diabetes tipo 2