A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement

Summary

This study presents a low-cost and easy-to-implement "real world" high-intensity interval training (HIIT) protocol for scientific research and discusses its efficiency for cardiorespiratory fitness.

Abstract

High-Intensity Interval Training (HIIT) has emerged as an interesting time-efficient approach to increase exercise adherence and improve health. However, few studies have tested the efficiency of HIIT protocols in a "real world" setting, e.g., HIIT protocols designed for outdoor spaces without specialized equipment. This study presents a "real world" training protocol, named "beep training", and compares the efficiency of a HIIT regiment versus a traditional long-duration Moderate-Intensity Continuous Training (MICT) regiment using this beep training protocol on VO₂ max of overweight untrained men. Twenty-two subjects performed outdoor running with MICT (n = 11) or HIIT (n = 11). Cardiorespiratory fitness was assessed before and after training protocols using a metabolic analyzer. Both training protocols were performed 3 days a week for 8 weeks using the Beep Test results. The MICT group performed the exercise program at 60%-75% of the maximum speed of the 20 m shuttle test (Vmax) and with a progression of the distance of 3,500-5,000 m. The HIIT group performed the interval exercise with 7-10 bouts of 200 m at 85%-100% of the maximum speed of the 20 m shuttle test (Vmax), interspersed with 1 min of passive recovery. Although the HIIT group presented a significantly lower training volume than the MICT group (p < 0.05) after 8 weeks of beep training, HIIT was superior to MICT in improving VO₂ max (MICT: ~4.1%; HIIT: ~7.3%; p < 0.05). The "real world" HIIT regiment based on beep training protocol is a time-efficient, low-cost, and easy-to-implement protocol for overweight untrained men.

Introduction

Robust evidence has shown that High-Intensity Interval Training (HIIT) induces similar or even superior positive physiological adaptations than a traditional long-duration Moderate-Intensity Continuous Training (MICT)^1,2,3. A HIIT session is composed of short bouts of high-intensity exercise interspersed with low-intensity exercise (active recovery) or rest (passive recovery). While a daily session with a MICT protocol lasts 30 to 60 min, on average, a daily session with HIIT may take half the time or less from a MICT session. Then, considering that sedentary individuals have....

Protocol

This study was approved by the Federal University of the Jequitinhonha and Mucuri Valleys Ethics and Research Committee. All participants were informed of the study objectives and experimental procedures of the study and signed a written informed consent form before their participation.

1. Experimental design

1. Select individuals who meet the inclusion criteria: nonsmoking healthy individuals aged between 30 and 50 years with body mass index (BMI) of ≥25 kg.......

Discussion

HIIT has become a time-efficient alternative to the traditional MICT. This studypresents a low-cost, easy-to-implement HIIT protocol for a real-world setting. Most studies have proven the health benefits of HIIT using laboratory-based HIIT protocols^6,10, and, recently, few studies have investigated the effects of real-world HIIT protocols in overweight untrained individuals^10,14.

Materials

Name	Company	Catalog Number	Comments
Beep Test software	Bitworks	N/A	version 2.0
Exercise Physiology Measurement & Analysis System	ADI INSTRUMENT	PL3508B80	PowerLab 8/35 and LabChart Pro software (which includes the Metabolic Module for calculating metabolic parameters such as VCO2, VO2, respiratory exchange ratio (RER) and minute ventilation) Bio Amp Gas Analyzer Gas Mixing Chamber Spirometer Thermistor Pod Exercise Physiology Accessory Kit
GraphPad Software	GraphPad Prism	N/A	version 7.00
Heart Rate monitor	Polar	N/A	RS800 Running Computer: The running computer displays and records your heartrate and other exercise data during exercise. 2. Polar WearLink W.I.N.D. transmitter: The transmitter sends the heart rate signal to the running computer. The transmitterconsists of a connector and a strap.
Sound Forge PRO software	Sound Forge	N/A	version 14.00
Treadmill	IMBRASPORT	N/A	Speed from 0 to 24 km/h. Elevation from 0 to 26%. Weight capacity for users up to 220 kg. 4 hp motor (220 v). Automatic lubrication system. With Safety Key and Emergency Stop Button. Runs 14 preset protocols: Bruce, Modified Bruce, mini Bruce, Naughton Ellestad, Balke, Balke-Ware, Astrand, Cooper, Kattus, Male Mader, Female Mader, Stanford and Modified Stanford. Run RAMP PROTOCOL.