Burn Fat & Build Endurance: Can Long-HIIT Deliver Results in 4 Weeks?

According to new research published in Sports Science for Health, 4-week high-intensity long-interval training (long-HIIT) significantly improved participants' aerobic capacity, measured by VO2 max. There were mixed results for anaerobic capacity, but some showed improvement. However, long HIIT significantly enhanced repeated sprint ability (RSA), allowing participants to maintain high-intensity efforts for longer. Neuromuscular function remained stable despite the increased speed achieved during RSA. These findings suggest that long-HIIT benefits athletes by improving both aerobic and sprint endurance without harming muscle function. For general fitness enthusiasts, long-HIIT offers time-efficient workouts to boost cardiovascular health. It's important to monitor fatigue and incorporate long-HIIT exercises with other exercises for a balanced routine.

Key Points

1. Aerobic Power Boost: The study found a clear benefit for aerobic capacity. V̇O2max, the maximum amount of oxygen your body can utilize, significantly increased after the long-HIIT program. This indicates a more efficient cardiovascular system, allowing for better oxygen delivery and utilization during exercise.

2. Individualized Anaerobic Capacity Response: While there wasn't a significant overall improvement in anaerobic capacity (the ability to perform high-intensity activities without oxygen), 60% of participants did show meaningful gains. This suggests long-HIIT may benefit some individuals more than others in terms of anaerobic adaptations, possibly due to pre-existing fitness levels.

3. Enhanced Repeated Sprint Ability (RSA): This is a crucial finding for athletes in sports requiring repeated bursts of speed. Long-HIIT significantly reduced the drop-off in performance typically seen during RSA tests. This suggests the improved ability to maintain high-intensity efforts with minimal decline, allowing for better performance throughout a game or competition.

4. Neuromuscular Fatigue Not Worsened: The study measured fatigue through muscle function tests. Despite achieving higher speeds during RSA post-HIIT, the degree of fatigue remained consistent. This indicates that while long-HIIT improved speed and endurance, it didn't exacerbate fatigue levels, which is positive for overall muscle function and performance over time.

5. Athletes: Consider Long-HIIT for Aerobic Gains and RSA: The study suggests long-HIIT can be a valuable tool for athletes. It effectively improves V̇O2max, a key marker of aerobic fitness, and enhances RSA, crucial for sports with repeated high-intensity efforts. Coaches can utilize this protocol to strategically improve athletes' cardiovascular health and performance.

6. Time-Efficient Workouts for General Fitness: If you're short on time, long-HIIT offers a great way to boost your aerobic fitness. The study protocol can be adapted for general fitness routines, providing significant health benefits in a shorter timeframe compared to traditional exercise methods.

7. Listen to Your Body and Train Smart: It's important to monitor your body's response to long-HIIT. While the study showed positive results, individual responses can vary. Be mindful of fatigue and adjust the training intensity or frequency to avoid overtraining. Consider incorporating long-HIIT with other forms of exercise for a well-rounded fitness routine.

Exploring the Impact of High-Intensity Long-Interval Training: A 4-Week Study

High-Intensity Interval Training (HIIT) has gained significant attention for its efficiency in enhancing cardiorespiratory fitness. One variant, High-Intensity Long-Interval Training (long-HIIT), which involves intervals of at least one minute at 85-100% of maximal oxygen uptake (V̇O2max), is particularly noted for its potential to induce comprehensive physiological adaptations. The study we are examining investigated the effects of a 4-week long-HIIT program on anaerobic capacity, repeated sprint ability (RSA), and neuromuscular function in active men. This blog post will delve into the methodology, results, and implications of these findings.

Understanding the Study

The primary aim of this study was to evaluate how a short-term long-HIIT regimen influences various aspects of physical performance. Twenty active men with an average V̇O2max of 44.8 ± 5.3 mL.kg−1.min−1 participated in the study. They underwent a series of tests before and after the training program to assess changes in aerobic and anaerobic capacity, RSA, and neuromuscular function.

Testing Protocols:

1. Incremental Running Test (TINC): To determine V̇O2max.

2. Supramaximal Test: To measure anaerobic capacity, involving running at 115% of the maximum velocity achieved in TINC until failure.

3. Repeated Sprint Ability Test (RSA): Consisting of 2 sets of 6 all-out 35-meter sprints.

4. Neuromuscular Function Tests: Including counter movement jumps (CMJ) and maximal isometric voluntary contractions (MVC) of knee extensors, both assessed pre- and post-RSA with femoral nerve electrical stimulation.

Training Protocol: The long-HIIT program comprised 11 sessions over 4 weeks, featuring 10 one-minute runs at 90% of the maximum velocity from the TINC test (VINC), with one-minute recovery periods between runs.

Results

1. Aerobic Capacity: V̇O2max significantly increased (P = 0.0001), indicating improved aerobic power.

2. Anaerobic Capacity: No significant overall changes were observed, though 60% of participants showed improvements above the smallest worthwhile change (0.2 × standard deviation of pre-HIIT).

3. Sprint Performance (RSA): Post-HIIT, there was a significant reduction in the performance decline typically observed during RSA (P = 0.01), suggesting enhanced sprint endurance.

4. Neuromuscular Function: Despite greater speeds achieved during RSA post-HIIT, the degree of neuromuscular fatigue, measured by reductions in MVC, high-frequency doublet, voluntary activation, and CMJ performance, remained consistent pre- and post-HIIT.

Discussion

The study's findings provide valuable insights into the physiological adaptations induced by long-HIIT, particularly in the context of aerobic power, anaerobic capacity, and neuromuscular function. Let’s break down these results and their broader implications.

Aerobic Power

The significant increase in V̇O2max highlights long-HIIT's effectiveness in boosting aerobic capacity. This is consistent with existing literature which shows that high-intensity training protocols are superior in enhancing V̇O2max compared to moderate-intensity continuous training (MICT). The improvement in V̇O2max suggests that the participants' cardiovascular systems became more efficient, allowing for greater oxygen delivery and utilization during intense exercise.

Anaerobic Capacity

While the study did not find a significant overall change in anaerobic capacity, the fact that 60% of participants showed meaningful improvements is noteworthy. This variability might be attributed to individual differences in anaerobic fitness levels and the participants' initial conditioning. It also suggests that long-HIIT may benefit some individuals more than others in terms of anaerobic adaptations.

Repeated Sprint Ability (RSA)

The significant reduction in performance during RSA post-HIIT is a crucial finding. This suggests that long HIIT can enhance the ability to maintain high-intensity efforts with minimal decline in performance, a critical attribute in many sports. Improved RSA could be due to enhanced metabolic efficiency and better muscle oxygenation, allowing athletes to sustain repeated sprints more effectively.

Neuromuscular Function

The neuromuscular assessments revealed no significant changes in the degree of fatigue experienced post-HIIT, despite higher speeds achieved during RSA. This indicates that while the training improved speed and endurance, the neuromuscular fatigue resistance remained stable. It suggests that long-HIIT did not exacerbate fatigue levels, which is positive for maintaining overall muscle function and performance over time.

Practical Implications

For Athletes and Coaches

1. Incorporating Long-HIIT for Aerobic Gains: The marked improvement in V̇O2max demonstrates that long-HIIT is an efficient way to enhance aerobic capacity. Athletes and coaches can use this protocol to improve cardiovascular fitness in a relatively short period.

2. Balancing Anaerobic Training: Given the mixed results in anaerobic capacity improvements, it might be beneficial to combine long-HIIT with other anaerobic-focused workouts, especially for athletes requiring significant anaerobic power.

3. Enhancing RSA: The improvement in RSA highlights long-HIIT's utility in sports requiring repeated high-intensity efforts, such as soccer, basketball, and rugby. Incorporating long-HIIT could enhance an athlete's ability to perform at high intensities consistently throughout a game.

4. Neuromuscular Health: The stable neuromuscular fatigue response suggests that long-HIIT does not negatively impact neuromuscular function, making it a safe addition to training regimens focused on endurance and speed.

For General Fitness Enthusiasts

1. Efficient Workouts: For those with limited time, long-HIIT offers a time-efficient way to boost aerobic fitness. The protocol used in the study can be adapted for general fitness, providing substantial health benefits without long hours of training.

2. Balanced Training: Incorporating both long-HIIT and other forms of exercise can provide a well-rounded fitness routine, addressing both aerobic and anaerobic systems.

3. Monitoring Fatigue: It's essential to monitor how the body responds to long-HIIT, ensuring that it does not lead to overtraining. Pay attention to signs of excessive fatigue and adjust the training load accordingly.

Conclusion

The study underscores the multifaceted benefits of a 4-week long-HIIT program, particularly in enhancing aerobic capacity and repeated sprint ability without significantly altering neuromuscular fatigue levels. While the improvements in anaerobic capacity were less consistent, the overall findings support the inclusion of long-HIIT in both athletic training and general fitness routines.

As with any training program, individual responses can vary, and it's crucial to tailor workouts to meet specific goals and needs. Whether you are an athlete aiming for peak performance or a fitness enthusiast seeking efficient workouts, long-HIIT offers a potent tool for improving cardiovascular health and physical performance.

By integrating the principles of long-HIIT into your training, you can leverage its benefits to enhance endurance, speed, and overall fitness, paving the way for sustained athletic success and improved health outcomes.

Journal Reference

Milioni, F., Millet, G.Y., de Poli, R.A.B. et al. Effects of 4-week high intensity interval training on anaerobic capacity, repeated-sprints performance and neuromuscular function. Sport Sci Health (2024). https://doi.org/10.1007/s11332-024-01214-8

Related

https://healthnewstrend.com/the-exercise-prescription-combating-heart-disease-through-exercise

https://healthnewstrend.com/low-vitamin-e-linked-to-higher-diabetes-risk-can-supplementation-help

https://healthnewstrend.com/strength-training-might-be-more-effective-than-aerobics-for-blood-sugar-control-in-type-2-diabetes

https://healthnewstrend.com/oan-a-comprehensive-guide-to-managing-obesity-associated-nephropathy

https://healthnewstrend.com/obesity-and-the-endocrine-system-understanding-the-link-between-fat-and-hormonal-imbalance

https://healthnewstrend.com/the-best-exercises-for-burning-fatthe-science-of-fat-loss

Disclaimer

The information on this website is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.