“Cardio”… Is it Optimal? Part 2

In part one of this discussion, I briefly discussed the pros and potential cons of steady state, “traditional”, cardio.

Pros:

• Improvement in aerobic capacity and endurance
• Initial potential for weight loss,
• Stress relief, well being, improvement in event times

Cons:

• Potential for muscle loss
• Negative metabolic adaptation(1)
• Blunting of protein synthesis

I would like to note, there is nothing wrong with steady state cardio. It is a great form of exercise if you are training to run farther, but the title of this series is “Is It Optimal?” It may not me the most optimal form of cardio for your desired outcomes.

So what kind of cardio can prevent muscle loss, improve resting metabolic rate, and burn more fat…in less time?*

High Intensity Interval Training (HIIT)

I’m sure many have heard of doing intervals, “oh yeah I do 30 seconds of running and a minute of walking/jogging”.

That is not exactly HIGH INTENSITY… If you can do your HIGH INTENSITY for more than 15 to 20 seconds, its not HIGH INTENSITY.

High Intensity Cardio is doing an all out-max-effort, running from the cops and a lion, SPRINT. If you are a pretty athletic person, this cannot be done on a treadmill. I wouldn’t be trying it on a treadmill at all. Disclaimer: If you have an injury, prone to injury or have a heart condition, HIIT may not be a safe option for you!

So how do I  recommend you do HIIT?

First, warm up properly, until you are warm and sweating. Start with an all out, 8-10 second sprint, then walk/recover for about 2-3 minutes (active recovery). Repeat this for about 4 to 6 rounds. Cooldown and stretch afterwards.

My favorite form of lower body HIIT is actually done on a stationary bike. Here is what I do:

• Warm Up for 5 Minutes at resistance level 10
• Sprint for 15 seconds on resistance level 20
• Pedal for 2 minutes on resistance level 10
• Repeat those intervals for 6 to 8 rounds
• Cool Down for 5 minutes on resistance level 5

After doing this, with all out effort on the sprints, your legs should feel dead, and pumped full of blood, like you just got done doing 500 squats. The reason I prefer the resistance bike is because it involves a lot more muscles than running and causes less muscle damage.

“Long duration running uses very little hip flexion and extension. Thus biomechanically you are training the hip flexors to move in a limited range of motion. In contrast cycling has a large range of motion for both hip flexion and extension. If you look at exercises like squats, and leg presses, these are very reliant on large hip mobility and range of motion, which as the figure below shows cycling encourages. (1)”

“Muscle damage is elicited to a greater extent during the eccentric or lowering phase of a movement when the muscle is contracting while lengthening while the least amount of damage is caused in the concentric phase in which the muscle shortens. Running has a high eccentric component. For example long distance running causes extreme muscle damage while ultra distance cycling (230 km) does not (1)”

So How Does HIIT increase fat burning for 24 to 72 hours after exercise?

HIIT, done properly, has been shown to increase mitochondria density, thus increasing the capacity for fat oxidation through out the day. I will spare the science details, but if interested just look up “Mitochondria Fat Metabolism”. Also, by preventing muscle loss, and even potentially increase some leg muscle, this in itself will help boost your metabolism throughout the day!

A 15 week study done on HIIT (6 – 30 second all out Wingate Sprints) vs. Steady State Cardio (1 hour @ 3mph) found that the participants doing HIIT lost almost 50% more body fat than the steady state group! (2)

HIIT can be done in many different forms. As long as you are doing something with all out (added resistance helps) effort for as long as you can (shouldn’t be able to last more than 20 seconds) and doing active recovery, it is HIIT. Use sled pushes, weighted jumps, car pushes, jump rope, etc. Get creative and switch it up!

 

Can HIIT increase aerobic capacity? YES!

Interestingly enough, it can! Not only will it help burn fat faster, but it can also help you increase your aerobic conditioning – without spending countless hours jogging in place! Martin J Gibala and his team of researchers found the following results in a breakthrough study at their lab:

• First, subjects were tested on a stationary bike pedaling at 80% Vo2 Max (measure of oxygen usage) for as long as they could maintain this intensity. They lasted an average of 25 minutes
• The subjects then did 2 weeks of intervals two to three times per week of 30 second supra-maximal sprints (175% vo2 max – this is HIGH INTENSITY) followed by 4 minutes of complete rest for 4 rounds total.
• The subjects then repeated the first 80% Vo2 max test, and lasted on average 50 minutes!
• This means they doubled their cardio endurance  and only really did 4 minutes of work in 2 weeks! Amazing!

(1).Wilson, et al. Concurrent Training: A Meta Analysis Examining Interference of Aerobic and Resistance Exercise. University of Tampa, FL. J Strength Conditioning.

(2) McGee, et al. Metabolic Adaptations to Short-term High-Intensity Interval Training: A Little Painfor a Lot of Gain? Exercise and Sport Sciences Reviews: American College of Sports Med: 2008

Sample Workout

Sample HIIT cardio for the stationary bike (use a spin bike or airdyne if you have access to one!) I recommend doing this on a more upper body focussed day, or as a stand alone workout.

• 5 min warmup on stationary bike, lvl 8 resistance – HR up to 130 BPM
• 15 second max effort, lvl 20 resistance – HR up to 160 BPM
• 2 min active recovery, lvl 8 resistance, 65 RPM’s, HR dropped to 145 BPM
• 15 second max effort, lvl 20 resistance – HR up to 170 BPM
• 2 min active recovery, lvl 8 resistance, 65 RPM’s, HR dropped to 150 BPM
• 15 second max effort, lvl 20 resistance – HR up to 175 BPM
• 2 min active recovery, lvl 8 resistance, 65 RPM’s, HR dropped to 155 BPM
• 15 second max effort, lvl 20 resistance – HR up to 175 BPM
• 2 min active recovery, lvl 8 resistance, 65 RPM’s, HR dropped to 155 BPM
• 15 second max effort, lvl 20 resistance – HR up to 180 BPM
• 2 min active recovery, lvl 8 resistance, 65 RPM’s, HR dropped to 160 BPM
• 15 second max effort, lvl 20 resistance – HR up to 175 BPM
• 2 min active recovery, lvl 8 resistance, 65 RPM’s, HR dropped to 155 BPM
• 5 min cooldown, lvl 5 resistance, 65 RPM’s, HR dropped to 120 BPM
• 10 minutes of foam rolling and static stretching

This whole workout lasts about 20 minutes.

If you are experiencing any lower body issues that limit you from doing high intensity lower body cardio (shin splints, plantar fasciitis, etc.) you can do HIIT workouts with battle ropes (click here for some awesome battle rope action!), kettle bells, boxing, medballs, or even lighter dumbbells or barbells. I recommend trying this Tabata style, or intervals of 20 seconds all out effort, with 10 seconds of complete rest in between, for 4 minutes total. Rest for a few minutes, or do some lifting, and repeat a few more times.