Steady State Cardio vs HIIT: Which is Superior for Fat Loss?

When most people decide they want to shed a few pounds the first thing that pops into their head is; I NEED TO START RUNNING. Jogging 3 miles 2-3 times per week is the normal routine most people undertake to shed unwanted fat. Let me start by saying this routine is better than nothing, and fat can definitely be lost partaking in this type of program. However, the question I always like to ask when engaging in an exercise program is not will it work, instead I ask; IS IT OPTIMAL?

The short answer, NO.

Let’s be clear, jogging, or in more scientific terms “steady state cardio (SSC),” is a good way to improve general fitness. For individuals who enjoy to jog for relaxation or social interaction I am all for it. However, for individuals trying decrease fat and maximize lean mass it is far from optimal and elicits no superior health benefits.

WHAT IS OPTIMAL?

High intensity interval training (HIIT) is currently making waves in the fitness industry, and for good reasons! HIIT is characterized by bouts of high and low intensity in various ratios.

For example:

• Warm Up for 5 minutes at a moderate intensity
• Perform 1 minute of maximal intensity cardio then 1 minute of low intensity cardio
  • Repeat this 10-20 times
• Cool Down for 5 minutes

Numerous studies have shown HIIT  to be superior to steady state cardio for maximizing lean mass and fat loss while being comparable to OR better than steady state cardio for cardiovascular health.

FAT LOSS

The majority of people looking to lose some fat would benefit more from HIIT than steady state assuming they have no health restrictions.  Why?

1. Burn more calories per unit of time. In addition, more calories are burned during the post-exercise period to return the body to resting levels.
2. Higher levels of growth hormone release during HIIT (compared to SSC) results in greater fat loss. The primary role of growth hormone increases from HIIT is to break down fat.
3. No decrease in metabolism like with steady state. The body adapts to high volume SSC. The energy-producing components of cells become much more efficient and thus fewer calories are expended.
4. Cellular adaptations that increase the capacity to burn fat

LEAN MASS

Muscle tissue is extremely important to hold on to as we age. As the main driver of metabolism in the body, it allows us to burn more energy at all points in the day. In addition, it gives us the ability to stay independent and perform daily tasks.  HIIT may not increase muscle mass but UNLIKE SSC it will not be detrimental to muscle and strength gains. Why?

1. Neuromuscular system interference: Steady-state cardio interferes with the adaptations made by the neuromuscular system during strength training. This results in less strength via a reduced ability to maximal contract muscles. If your goal is to gain lean mass contracting fewer motor units is suboptimal.
2. Energy Use: While HIIT uses more energy than steady state the fashion in which energy is depleted during steady state cardio cause higher levels of a byproduct that reduces protein synthesis (formation of new muscle or repair of injured muscle).
3. Effect on testosterone: Chronic high volume endurance training has been shown to reduce testosterone in men.

CARDIOVASCULAR HEALTH

The numerous benefits of SSC are irrefutable. However, studies show that HIIT results in similar, in some cases, superior adaptations.

1. Beneficial thickening of the heart muscle.
2. Increased contraction force of the heart (stronger beats).
3. More blood pushed out with each beat.
4. Increased ability for the body to use oxygen. Oxygen enters the cells from the blood easier.
5. Increased ability of the body to use insulin. Resulting in better blood sugar control.
6. Increased capacity for fat breakdown by the cells.

CONCLUSION

The mode of cardio that you chose to partake in should be answered by one simple question. WHAT IS MY GOAL? If your goal is to be a better long distance runner then SSC is going to be the focus of your program. However, if your goal is to improve health or body composition your workouts should be focused around HIIT cardio and weight lifting assuming you have no medical restrictions.