Exercise Intensity for Fitness

(CEX Trial)

Overseen By Garett S Jackson, MSc.

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of British Columbia

Must not be taking: Immunomodulatory, Anti-inflammatory

Disqualifiers: Diabetes, Hypertension, Extreme diet, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 21

Duration: 6 weeks

50 Participants Needed

Trial Summary

What is the purpose of this trial?

Introduction This study investigates the effects of different intensities of indoor cycling on various health measures. Participants will perform a maximal cycling test to determine their maximal fitness - a strong predictor of overall health - before and after a 6-week training intervention. Blood samples will also be obtained to look at various physiological markers related to extracellular vesicles, inflammation, and metabolism. Who can participate? Healthy young adults who between 18 and 40, are free of immune disease, with a normal body mass index can join this study. They will be divided into three groups: * One group will ride a bike at a moderate pace. * Another group will ride a bike at a slightly harder pace. * The third group won't change their usual daily activities and will continue living as they normally do. What does the study involve? Each exercise session aims to burn a specific amount of calories: 350 for males and 300 for females. Participants cycle 3 times a week for 6 weeks. At the end, we'll repeat the bike test and take another blood sample to see if there have been any changes due to the exercise. Why is this research being done? The researchers want to see how different intensities of exercise impact health and fitness. This may help people make better choices about how much and what type of exercise they should do. What happens after the study? Researchers will analyze the data from the study and see if any differences exist between the protocols. If the participant is interested, we will also provide their blood test results, and the results from their max test.

Do I have to stop taking my current medications for the trial?

The trial protocol does not specify if you need to stop taking your current medications. However, if you require immunomodulatory medication for an autoimmune disease or rely heavily on over-the-counter anti-inflammatory medications, you may be excluded from participating.

What data supports the idea that Exercise Intensity for Fitness is an effective treatment?

The available research shows that high-intensity interval training (HIIT) can lead to significant improvements in aerobic fitness and body composition. For example, in breast cancer survivors, HIIT was found to improve aerobic capacity more than moderate-intensity exercise. Additionally, a study on sedentary individuals at risk of cardiovascular disease showed that combining moderate-intensity exercise with HIIT led to a 10.1% increase in cardiorespiratory fitness, compared to a 3.9% increase with moderate-intensity exercise alone. This suggests that HIIT can be more effective than moderate-intensity exercise in improving fitness levels. ^{1 2 3 4 5}

What safety data exists for exercise intensity treatments in clinical trials?

Safety data for exercise intensity treatments, such as HIIT and MICT, indicate that these protocols are generally well-tolerated across various populations, including older adults and those with cardiovascular disease. Studies show a low rate of major adverse cardiovascular events, with HIIT having 1 major event per 17,083 sessions in cardiac rehabilitation settings. Both HIIT and MICT have shown similar safety profiles, with minor adverse events primarily being musculoskeletal complaints. Overall, these exercise protocols are considered safe with proper supervision and adherence to guidelines. ^{6 7 8 9 10}

Is Heavy Intensity Continuous Training, Moderate Intensity Continuous Training a promising treatment for fitness improvement?

Yes, both Heavy Intensity Continuous Training and Moderate Intensity Continuous Training can improve fitness. Combining moderate exercise with high-intensity intervals may lead to better cardiorespiratory fitness, which is important for heart health. ^{3 11 12 13 14}

Eligibility Criteria

Healthy young adults aged 18-40 with a normal body mass index can participate. They should not have any immune diseases and must be willing to undergo indoor cycling sessions and blood tests.

Inclusion Criteria

Have a body mass index (BMI) between 18.5 and 30 kg/m^2

Perform between 60 and 200 minutes of aerobic physical activity per week

I do not have a history of heart disease or diabetes.

Exclusion Criteria

Are an elite endurance athlete, or training specifically for an endurance event (>3 structured aerobic training sessions, or >150 min of specific aerobic-based/endurance training per week)

Adhere to an extreme diet (e.g., ketogenic diet, time restricted feeding)

Smoke cigarettes

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Pre-Intervention Testing

Participants undergo baseline testing including maximal cycling test and blood sample collection

1 week

1 visit (in-person)

Treatment

Participants engage in 6 weeks of moderate or heavy intensity cycling training, or no additional exercise for the control group

6 weeks

18 visits (in-person)

Post-Intervention Testing

Participants repeat the maximal cycling test and blood sample collection to assess changes

1 week

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Control Group
• Heavy Intensity Continuous Training
• Moderate Intensity Continuous Training

Trial Overview The study is testing the effects of different intensities of indoor cycling on fitness, health markers in the blood, inflammation, and metabolism over a period of 6 weeks. Participants will cycle at moderate or heavy intensity or continue their usual activities as a control group.

Participant Groups

Group I: Moderate Intensity Continuous Training Experimental Treatment 1 Intervention

In this allocation, participants cycle at 70% the resistance associated with their lactate threshold

Group II: Heavy Intensity Continuous Training Experimental Treatment 1 Intervention

In this allocation, participants cycle at the resistance associated with their lactate threshold, with an additional 10% of the difference between their LT and maximal achieved watts during the test.

Group III: Control Group Experimental Treatment 1 Intervention

This group undergoes the same testing protocols as the intervention groups, but is prescribed no additional exercise.

Who Is Running the Clinical Trial?

University of British Columbia

Lead Sponsor

Trials

1,506

Recruited

2,528,000+

Findings from Research

High-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) both improved aerobic capacity (VO2peak) and waist circumference in breast cancer survivors over a 12-week program, but there were no significant differences between the two training methods.

While HIIT led to increases in minute ventilation and peak workload, it did not result in a greater improvement in VO2peak compared to MICT, suggesting that both training intensities are beneficial for previously trained breast cancer survivors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Additional cardiovascular fitness when progressing from moderate- to high-intensity exercise training in previously trained breast cancer survivors. Bell, RA., Baldi, JC., Jones, LM.[2021]

A 3-week rehabilitation program using high-intensity interval training (HIIT) was safe for female breast cancer survivors, with no reported adverse events, and effectively reduced body fat without affecting overall body mass.

Both HIIT and low-to-moderate intensity exercise (LMIE) improved quality of life and reduced cancer-related fatigue, but HIIT was more time-efficient, making it a practical option for enhancing health in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A 3-week multimodal intervention involving high-intensity interval training in female cancer survivors: a randomized controlled trial. Schmitt, J., Lindner, N., Reuss-Borst, M., et al.[2021]

Both continuous moderate intensity exercise training (CMIET) and CMIET combined with a single weekly high intensity interval training (HIIT) session led to clinically meaningful improvements in cardiorespiratory fitness, with the CMIET + HIIT group showing a 10.1% increase in VO2max over 12 weeks.

Participants in the CMIET + HIIT group demonstrated 100% adherence to the training regimen, indicating that this combination of exercise is well-tolerated by previously inactive individuals at moderate risk of cardiovascular disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Is moderate intensity exercise training combined with high intensity interval training more effective at improving cardiorespiratory fitness than moderate intensity exercise training alone? Roxburgh, BH., Nolan, PB., Weatherwax, RM., et al.[2022]

In a study involving 73 coronary patients over 8 weeks, high intensity interval training (HIIT) led to a greater improvement in peak oxygen consumption (VO2peak) compared to moderate continuous training (MCT), with increases of 4.5 ml/kg/min for HIIT versus 2.46 ml/kg/min for MCT.

HIIT also significantly enhanced heart rate recovery (HRR) at both the first and second minute post-exercise, indicating better cardiovascular recovery compared to MCT, which suggests that HIIT may be more beneficial for coronary patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients. Villelabeitia-Jaureguizar, K., Vicente-Campos, D., Senen, AB., et al.[2018]

High-intensity interval training (HIIT) is significantly more effective than moderate intensity training (MIT) for improving aerobic capacity (peak VO2) and left-ventricular ejection fraction (LVEF) in heart failure patients, based on a meta-analysis of 17 studies.

There is no significant difference in outcomes between MIT and combined aerobic and resistance training (CT), indicating that adding resistance training does not hinder aerobic improvements in heart failure patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exercise Mode in Heart Failure: A Systematic Review and Meta-Analysis. Edwards, J., Shanmugam, N., Ray, R., et al.[2023]

Maximal-intensity aerobic interval training (MAIT) significantly improved maximal oxygen uptake (O2max) by 31% in patients with acute coronary syndrome, compared to a 17% increase with high-intensity aerobic interval training (HAIT), indicating that MAIT may be more effective for enhancing cardiovascular fitness.

Both MAIT and HAIT were found to be safe, with no major cardiovascular or musculoskeletal complications reported during the 6-week training period, suggesting their suitability for cardiac rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effect and Safety of Aerobic Interval Training According to Exercise Intensity in Acute Coronary Syndrome. Kim, C., Choi, HE.[2021]

A scoping review of 69 studies on high-intensity interval training (HIIT) in older adults found that HIIT protocols are generally well-tolerated and can provide significant health benefits, particularly in improving cardiorespiratory fitness.

Most research has focused on healthy older adults, highlighting a need for larger studies and more investigation into HIIT's effects on older adults with various health conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-Intensity Interval Training in Older Adults: a Scoping Review. Marriott, CFS., Petrella, AFM., Marriott, ECS., et al.[2021]

High-intensity interval training (HIIT) is as effective, if not more so, than traditional moderate-intensity continuous training (MICT) for patients with cardiovascular disease, based on a systematic review of 23 studies involving 1117 participants.

The safety profile of HIIT in cardiac rehabilitation is promising, with only one major cardiovascular adverse event reported per 17,083 training sessions, indicating that HIIT can be safely implemented in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-Intensity Interval Training for Patients With Cardiovascular Disease-Is It Safe? A Systematic Review. Wewege, MA., Ahn, D., Yu, J., et al.[2021]

In a study of 81 heart disease patients with very high cardiovascular risk, both moderate and high-intensity interval training (MIIT and HIIT) were found to be safe, with no adverse outcomes reported during the training.

While there were no statistically significant differences in overall exercise improvements between the training types, the HIIT group showed a trend towards greater improvements in exercise tolerance, suggesting it may be more effective than continuous moderate intensity training (MICT).

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and improvement in exercise tolerance with interval training vs moderate-intensity continuous training in heart disease patient of very high cardiovascular risk. Pineda-García, AD., Lara-Vargas, JA., Ku-González, A., et al.[2022]

In an 8-week study involving 24 overweight/obese middle-aged men, both high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) resulted in similar improvements in cardiovascular fitness and fat loss, indicating that HIIT can be an effective alternative to traditional exercise methods.

Participants in both training groups reported high enjoyment levels and adherence rates over 90%, suggesting that HIIT is not only time-efficient but also well-received by individuals looking to improve their metabolic health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of low-volume high-intensity interval training on cardiometabolic health and psychological responses in overweight/obese middle-aged men. Poon, ET., Little, JP., Sit, CH., et al.[2022]

Exercise programs for conditioning and rehabilitation must be specifically designed for either strength development or aerobic fitness, as they require different approaches in terms of intensity, duration, and frequency.

Strength training focuses on low repetitions with high resistance, while aerobic exercise involves longer durations with many repetitions, leading to distinct physiological adaptations in the body.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Strength training and aerobic exercise: comparison and contrast. Knuttgen, HG.[2016]

In a study of 31 participants undergoing high-intensity functional training (HIFT) for six weeks, no significant improvements in physical performance measures such as jump height, sprinting speed, or handgrip strength were observed in either high or moderate training volume groups.

The analysis indicated that variations in training volume and frequency did not affect performance outcomes, suggesting that simply increasing training intensity may not lead to enhanced physical capabilities in HIFT practitioners.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Six Weeks of High-Intensity Functional Training on Physical Performance in Participants with Different Training Volumes and Frequencies. Teixeira, RV., Batista, GR., Mortatti, AL., et al.[2020]

Both high-intensity interval training (HIIT) and moderate-intensity training (CONT) improved aerobic fitness equally over a 6-week period in a study involving 20 adults.

However, the two training methods led to different changes in cardiorespiratory coordination, suggesting that the intensity of training can influence how the body adapts to endurance exercise.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cardiorespiratory coordination reveals training-specific physiological adaptations. Garcia-Retortillo, S., Gacto, M., O'Leary, TJ., et al.[2021]

Both high-intensity interval training (I HIGH) and lower intensity training (105% CP) effectively reduced the time it takes for the body to reach steady-state oxygen consumption during moderate and heavy exercise, indicating improvements in aerobic performance.

The training intensity did not significantly affect the physiological responses, such as blood lactate levels and muscle activation, suggesting that both training methods can be equally beneficial for enhancing exercise efficiency.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Short-term interval training at both lower and higher intensities in the severe exercise domain result in improvements in V̇O₂ on-kinetics. Turnes, T., de Aguiar, RA., de Oliveira Cruz, RS., et al.[2018]

References

1. Germany pubmed.ncbi.nlm.nih.gov

Additional cardiovascular fitness when progressing from moderate- to high-intensity exercise training in previously trained breast cancer survivors. [2021]

2. United States pubmed.ncbi.nlm.nih.gov

A 3-week multimodal intervention involving high-intensity interval training in female cancer survivors: a randomized controlled trial. [2021]

3. Turkey pubmed.ncbi.nlm.nih.gov

Is moderate intensity exercise training combined with high intensity interval training more effective at improving cardiorespiratory fitness than moderate intensity exercise training alone? [2022]

4. Netherlands pubmed.ncbi.nlm.nih.gov

Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients. [2018]

5. Switzerland pubmed.ncbi.nlm.nih.gov

Exercise Mode in Heart Failure: A Systematic Review and Meta-Analysis. [2023]

6. United States pubmed.ncbi.nlm.nih.gov

The Effect and Safety of Aerobic Interval Training According to Exercise Intensity in Acute Coronary Syndrome. [2021]

7. Switzerland pubmed.ncbi.nlm.nih.gov

High-Intensity Interval Training in Older Adults: a Scoping Review. [2021]

8. England pubmed.ncbi.nlm.nih.gov

High-Intensity Interval Training for Patients With Cardiovascular Disease-Is It Safe? A Systematic Review. [2021]

9. Mexico pubmed.ncbi.nlm.nih.gov

Safety and improvement in exercise tolerance with interval training vs moderate-intensity continuous training in heart disease patient of very high cardiovascular risk. [2022]

10. England pubmed.ncbi.nlm.nih.gov

The effect of low-volume high-intensity interval training on cardiometabolic health and psychological responses in overweight/obese middle-aged men. [2022]

11. United States pubmed.ncbi.nlm.nih.gov

Strength training and aerobic exercise: comparison and contrast. [2016]

12. Switzerland pubmed.ncbi.nlm.nih.gov

Effects of Six Weeks of High-Intensity Functional Training on Physical Performance in Participants with Different Training Volumes and Frequencies. [2020]

13. Germany pubmed.ncbi.nlm.nih.gov

Cardiorespiratory coordination reveals training-specific physiological adaptations. [2021]

14. Germany pubmed.ncbi.nlm.nih.gov

Short-term interval training at both lower and higher intensities in the severe exercise domain result in improvements in V̇O₂ on-kinetics. [2018]