Heart Rate During Exercise in Type 2 Diabetes

Summary

Exercise training is a cornerstone for the prevention and treatment of metabolic disorders and associated cardiometabolic complications such as type 2 diabetes mellitus (T2D) and hypertension. Similar to the beneficial health effects after performing conventional continuous exercise modalities, high intensity interval training (HIIT) has been reported as an effective alternative exercise-modality to improve glucose homeostasis in both prediabetes subjects and individuals with T2D diagnosed. In this regard, although multiple HIIT-based interventions commonly report acute and long term benefits on body composition, cardiorespiratory fitness and insulin sensitivity in metabolically compromised subjects, little is known about the acute cardiovascular response (i.e., at heart rate level) during HIIT in subjects with different glucose control.

HIIT is described as performing brief periods of exercise at vigorous or maximal intensity, interspersed with inactive or low intensity recovery phases of variable duration. In order to characterize different HIIT-based protocols, exercise intensity is usually defined as relative percentages of individual maximal cardiorespiratory fitness (VO2max) or relative maximal power output values. Nevertheless, the need for specific technological equipment to assess these parameters usually limit the prescription and recommendations of HIIT in clinical settings and other public health contexts at massive level. Additionally, the use of self-perceived exertion scales and heart rate (HR) variations upon HIIT have been demonstrating to be accessible and feasible strategies to regulate exercise intensity during HIIT. For example, it was reported that HR and self-perceived exertion scores increased progressively in T2D subjects, parallel to the oxygen consumption rate throughout an acute HIIT session performed on cycle ergometer. Consequently, it is conceivable to hypothesize that determining HR variations during HIIT might optimize the recommendation of this training methodology in metabolically compromised subjects as those at risk or with T2D diagnosed. Therefore, the aim of the present study was To describe and compare the acute heart rate changes in response to an incremental maximal exercise test and a single HIIT session between normoglycaemic (NG), prediabetes (Pre-T2D) and type 2 diabetes mellitus (T2D) subjects.

Conditions

• Type2 Diabetes Mellitus
• Hyperglycemia
• Heart Rate
• Exercise Training

Interventions

OTHER

Behavioral

The resting heart rate (HRrest), maximum HR (HRmax), HR recovery (HRRTEST), delta HR recovery (ΔHRRTEST) were measured by continuous telemetric heart rate sensor (Polar FT4, PolarTM, Finland) during an incremental exercise test designed to obtain maximum oxygen consumption (VO2max) on a cycle ergometer (Lode Corival, Groningen, The Netherlands) similar with previous studies using similar cohort. An indirect calorimetry/ergospirometry system (Ultima CPXTM metabolic system, Medgraphics, Minnesota, USA) was used to measure VO2max until volitional exhaustion. Thus, the modified Astrand volitional protocol was applied in the participants of all NG, Pre-T2D and T2D groups increasing the load (i.e., Watts) 25 W each 2 min to women, and 50 W each 2 min to men.

OTHER

Exercise training intervention

Subjects also participated in a single HIIT session composed of 10-cycling intervals, using a Lode Corival cycle ergometer. The exercise session consisted of 1-minute cycling at high intensity (workload during each interval was set at \~80-100 % maximal power achieved during the incremental exercise test with a workload that allowed to work until the volitional muscle failure in 1-minute), followed by 2-minutes of inactive resting period (sitting still on the cycle ergometer), and was repeated 10 times (1x2x10 protocol; 1:2:10 to work:rest:repetitions respectively).

Sponsors & Collaborators

• Universidad de La Frontera

  collaborator OTHER

• Universidad de Los Lagos

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2018-01-04

Primary Completion

2018-04-04

Completion

2018-04-07

Countries

• Chile

Study Locations