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Completed

NCT Number: NCT03285386

Priming Exercise in Type 1 Diabetes

Critical power is an important threshold in exercise physiology, and is an important determinant of the ability to tolerate high-intensity exercise. The ability to tolerate such exercise is drastically impaired in certain chronic conditions, such as type 1 diabetes. Whilst the most important physiological factors that determine critical power have yet to be determined, previous work from our laboratory suggests that it is related to the speed of oxygen uptake at the onset of exercise. This study will look to utilise "priming" exercise as an intervention to improve the speed of these oxygen uptake "kinetics", and thus critical power and exercise tolerance in individuals with type 1 diabetes. We hypothesize that oxygen uptake kinetics will be faster and critical power will be higher when exercise is performed with compared to without a prior bout of high-intensity priming exercise in a population of individuals with type 1 diabetes.

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Key information

Age range

18 year–40 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Liverpool Hope University

Liverpool, Merseyside, L169JD, United Kingdom

About this study

The ability to tolerate high-intensity exercise, or exercise tolerance, is a key factor that can influence clinical outcomes in a range of conditions. The "critical power" is an important physiological threshold that demarcates exercise intensities that can be sustained for prolonged periods (i.e. below critical power) from intensities that result in exhaustion in a relatively short period of time (i.e. 2-30 minutes, above critical power). Critical power is therefore a key determinant of exercise tolerance. The speed with which oxygen uptake rises at the onset of exercise (i.e. oxygen uptake "kinetics") has been shown by work from our laboratory to be a key determinant of critical power. One intervention that can acutely improve the oxygen uptake kinetics is the performance of a prior bout of high-intensity exercise, known as "priming exercise". Patients with type 1 diabetes have previously been shown to have impaired exercise tolerance compared to healthy controls. The performance of priming exercise therefore represents a potential intervention to acutely improve oxygen uptake kinetics, and therefore critical power and exercise tolerance, in type 1 diabetic individuals. The purpose of this study is therefore to assess the influence of priming exercise on oxygen uptake kinetics and critical power in a population of type 1 diabetic individuals.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Suffering from Type 1 diabetes with a diagnosed disease duration of 2 - 20 years and no comorbidities.

Exclusion criteria

History of stroke, congestive heart failure, hypertension, or cardiopulmonary disease.

Current smoking or have been smoking within the last 12 months Symptomatic autonomic or distal neuropathy HbA1c > 64 mmol/mol Hypoglycaemia unawareness in the last 6 months Taking any medications other than insulin.

Treatment and study plan

Priming exercise

Behavioral

All participants will perform a bout of high-intensity "priming" exercise for 6 minutes, 10 minutes prior to undertaking an exhaustive exercise test on four separate occasions.

Control Exercise

Behavioral

All participants will perform 3 minutes of baseline cycling prior to undertaking an exhaustive exercise test on four separate occasions.

Primary outcomes

  1. Critical power

    Time frame: 3-9 weeks

    The power asymptote of the hyperbolic relationship between power and the tolerable duration of exercise.

  2. Phase II time constant of pulmonary oxygen uptake kinetics

    Time frame: 3-9 weeks

    Time taken for oxygen uptake to attain 63% of its asymptotic amplitude.

  3. Time constant for muscle deoxygenation kinetics (assessed by near-infrared spectroscopy)

    Time frame: 3-9 weeks

    Time taken for muscle deoxyhaemoglobin to attain 63% of its asymptotic amplitude.

Secondary outcomes

  1. W'

    Time frame: 3-9 weeks

    Curvature constant of the power-duration relationship. Finite work capacity available above critical power.

  2. Time constant for heart rate kinetics

    Time frame: 3-9 weeks

    Time taken for heart rate to attain 63% of its asymptotic amplitude.

Sponsors and collaborators

Lead sponsor

Liverpool Hope University

Other

Registry information

Official study title

The Effects of Prior Exercise on Pulmonary Oxygen Uptake Kinetics and the Power-Duration Relationship in Type 1 Diabetes

Acronym: PET1D

Important dates

Study start
2018
Primary completion
2018
Study completion
2018
First posted
Sep 18, 2017
Registry last updated
Mar 1, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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