Podcast Summary: The Dr. Shannon Show

Episode: Body Recomposition Capsule #7: How to Do Cardio
Host: Dr. Shannon Ritchey, PT, DPT
Date: January 7, 2026

Episode Overview

In this episode, Dr. Shannon Ritchey delves deep into the role of cardio in body recomposition, debunking myths, presenting updated science, and outlining practical recommendations. She emphasizes balancing cardio with strength training, highlights how to dose different intensities, and guides listeners toward a sustainable, effective cardio regimen for improved health, longevity, and body composition.

Key Discussion Points & Insights

1. Evolving Views on Cardio in Recomposition (02:40)

• Dr. Shannon acknowledges her early misconceptions, emphasizing her evolution from recommending lots of cardio to almost none, and now finding a science-backed middle ground:
  • Quote:
    “Cardio and strength training don't need to work against each other when they're dosed correctly. In fact, your cardio will help your strength work and your strength work will help your cardio.” [03:45]

2. The Science of Energy Expenditure (05:10)

• Calorie burn from exercise is less predictable and less impactful than most believe.
• There's ongoing debate among researchers: Does the body compensate for increased activity by reducing energy use elsewhere?
  • 2025 studies conflict: Some show energy expenditure plateaus, others find no compensation.
  • Quote:
    “Odds are our metabolism is extremely complex and it's more individual. So I don't recommend tracking calories because we just don't have the answers.” [08:22]
• Fitness trackers often overestimate workout calorie burn; relying on these metrics may sabotage fat loss attempts.

3. Cardio's Role in Body Recomposition (10:15)

• Building muscle yields a higher, more sustainable payoff than focusing solely on burning calories.
• Cardio is still an important—but smaller—part of the body recomposition equation, primarily to keep total energy expenditure up.
• Overemphasizing cardio or doing too much can lead to burnout or injury.

4. How Much Cardio Should You Do? (12:25)

• World Health Organization recommends:
  • 150 minutes/week of light to moderate intensity OR
  • 75 minutes/week of moderate to high intensity cardio (in addition to strength training)
• Dr. Shannon’s personal routine:
  • Steady state classes (15 minutes, 1–2x/week)
  • Daily walks (~30 minutes, light to moderate, often with additional weight from carrying her child)
• Adjust intensity and frequency to fit recovery capacity.
  • Quote:
    “Some people feel great doing shorter, slightly higher intensity cardio sessions and some people like longer, more low to moderate intensity sessions. Like me.” [14:05]

5. Simplifying Cardio Intensity: Heart Rate Zones Explained (16:20)

• Dr. Shannon encourages a simplified, individualized approach:
  • Quote:
    “Let's just simplify it. Consistently challenge your cardio in any zone on a weekly basis. If you want to add intensity or time, do it, but you want to increase your heart rate regularly. As long as you're recovering, do as much cardio as you can stay consistent with.” [17:11]
• Zone 1: Leisurely, barely increased heart rate (walking)
• Zone 2: Light-moderate, can talk but heart rate increased (~60–70% max HR)
• Zones 3 & 4: Moderately hard; traditional group fitness, running, spin. Caution: harder to recover from, risk of fatigue/hunger spikes.
• Zone 5: All-out, HIIT style; very potent but very taxing, should be used sparingly.

6. Practical Recommendations By Zone (18:50)

Zone 1

• Casual, easy movement (leisure walk).

Zone 2

• Great for body recomposition; easy to recover from, supports cardiovascular health.

Zone 3 & 4

• Harder cardio (boot camp, spin, running).
• Burns more during the session but can negatively impact strength training performance if overdone.

Zone 5

• High Intensity Interval Training (HIIT); recommend only if recovery and strength are well managed.

• Max: 1–2 sessions per week.

• For those who dislike HIIT, try REHIT (Reduced Exertion HIIT): 2x 30-second all-out sprints with 1–3 min rest, for a total of 60 seconds of hard work plus warm-up/cooldown (see episode 182 for details).

  • Quote:
    “A lot of people will choose Zone 5 cardio because they think it accelerates fat loss. But it really doesn’t cause a lot of fat loss. … If you’re only doing HIIT one or maybe two times per week, which is what I recommend in a body recomposition phase, it likely won’t have a huge impact on fat loss.” [23:14]

7. Signs of Too Much Cardio (27:20)

• Excessive cardio won’t “make you puffy” or directly stall fat loss but:
  • May lead to overeating, decreased recovery, higher injury risk.
• Warning signs:

  • Poor sleep

  • Stalled strength gains

  • Excessive fatigue or soreness

  • Quote:
    “Signs that you’re doing too much cardio: poor sleep, your strength is stalling, excessive fatigue, excessive soreness. All of these might indicate your dosage of cardio is just a little too high.” [28:43]

8. Cardio vs. Strength: What Comes First? (29:35)

• If time-constrained, always choose strength training for body recomposition—especially in a calorie deficit.
• Excess cardio without strength and adequate protein may lead to loss of muscle, not just fat.
  • Quote:
    “If you only have time for one, choose strength training. … Lots of cardio without lifting and adequate protein can increase the chance that a meaningful portion of the weight you lose is lean mass. That is negative for body composition.” [29:55]

Timestamps of Important Segments

| Time | Segment | |------------|------------------------------------------------------| | 02:40 | Dr. Shannon’s changing perspectives on cardio | | 05:10 | Scientific debates on calorie burn & compensation | | 10:15 | Cardio vs. muscle-building for recomposition | | 12:25 | Evidence-backed cardio dosage recommendations | | 16:20 | Simplifying cardio: Heart rate zones explained | | 18:50 | Practical breakdown of zones & examples | | 23:14 | Zone 5/HIIT myths and best uses | | 27:20 | How to know you're doing too much cardio | | 29:35 | Cardio or strength: Which to prioritize |

Notable Quotes & Memorable Moments

• “Cardio and strength training don't need to work against each other when they're dosed correctly.” [03:45]
• “Odds are our metabolism is extremely complex and it's more individual. So I don't recommend tracking calories because we just don't have the answers.” [08:22]
• “Let's just simplify it. Consistently challenge your cardio in any zone on a weekly basis.” [17:11]
• “A lot of people will choose Zone 5 cardio because they think it accelerates fat loss. But it really doesn’t cause a lot of fat loss. … It likely won’t have a huge impact on fat loss.” [23:14]
• “Signs that you’re doing too much cardio: poor sleep, your strength is stalling, excessive fatigue, excessive soreness.” [28:43]
• “If you only have time for one, choose strength training. … Lots of cardio without lifting and adequate protein can increase the chance that a meaningful portion of the weight you lose is lean mass. That is negative for body composition.” [29:55]

Conclusion & Takeaways

• Cardio is a valuable health tool for body recomposition, but muscle-building through strength training is primary.
• Prioritize 150 minutes/week of light/moderate or 75 minutes/week of moderate/high intensity cardio, but don’t excessively chase calorie burn.
• Cardio intensity should be varied to your preference and recovery—no need to obsess over zones unless you enjoy using them.
• Watch for signs of overtraining and always prioritize adequate recovery and muscle maintenance.
• For a simplified approach: “Do cardio you enjoy, dose it alongside strength training, and focus on what you can recover from consistently.”

Stay tuned for the next episode, focusing on how to track recovery and optimize your fitness dosage.