Coach Chris here at the Critical Bench Compound with my good friend Dr. Boz—and we’re rolling into Workout #3 of our metabolic series. If you missed the first two, we covered upper body + CGM basics (Part 1) and leg-day glucose dynamics (Part 2). Today’s session leans cardiorespiratory with fast moves and minimal rest so you can see how cardio shifts your blood sugar in real time.

“When you store sugar and then circulate it to use it, you’ll see it mobilize after a workout.” — Dr. Boz

We also had a quick wardrobe change: shout-out to the “I Survived the Sardine Challenge” tee—yes, we’ll explain!

Why This Matters

People often email Dr. Boz: “I’m trying to lower my A1c, but every time I exercise my sugars go up. Should I stop?” The answer is no—that rise is your muscles mobilizing stored glycogen for energy. This is hormesis in action: healthy peaks and valleys beat a chronic, smoldering “meh” metabolism every time.

“You need to peak to have a valley. Cardio can raise glucose temporarily—and that’s part of getting healthier.” — Dr. Boz

The Workout Circuit (Cardiorespiratory Focus)
Two rounds, minimal rest

  1. Jump Squats – 10 reps
  2. Skater Hops – 10 reps each way (balance + power)
  3. Jump Rope – 30 seconds (yes, we had to reset so we didn’t whack each other 😅)

Heart rate snapshots:

  • Chris peaked around 159–176 bpm, then trended down post-sets.
  • Dr. Boz peaked around 177 bpm, easing down more slowly (she “runs hot”).
     Bonus variable: Florida heatwave + no A/C = honest sweat.

Real-Time Glucose Insights (Cardio Edition)

Starting reads before we moved: Chris ~119 mg/dL, Dr. Boz ~103 mg/dL.
 Post-circuit, Chris drifted up toward ~127, with earlier peaks near 139 within the last 30 minutes. Dr. Boz nudged up but remained close to baseline.

What that means:

  • Cardio also mobilizes glucose—often less sharply than heavy leg work, but it can last a bit as your body keeps fueling recovery.
  • A temporary rise isn’t “bad control”—it’s energy delivery. Watch the trend down as you recover.

Sleep, Metabolism & the “Janitor” Analogy

Think of sleep like the school janitor: cleanup starts with trash and dust, and the polish happens in the 5th–7th hour. Miss those hours frequently and your “hallways” never shine—hello, metabolic and cognitive drag.

CGM at night reveals patterns:

  • Healthy trend: sugars glide down into the 65–80 mg/dL zone by morning (with ketones quietly supplying steady fuel).
  • Red flag pattern: a sine wave all night can hint at sleep apnea—stress surges push glucose up, brief wake-ups bring it down, repeat. If your fasting numbers rarely hit the 70s–80s, there’s work to do.

The Sardine Challenge (Metabolic Reset You’ll Actually Feel)

About that shirt… Dr. Boz uses a 72-hour Sardine Challenge for clients who aren’t ready for a full fast:

  • Rules: The 72-hour clock starts with your first bite of sardines and ends with your last can—no “binge finish.”
  • Why sardines? Whole-food protein + fat, nutrient-dense, portable, inexpensive, and hugely satiating. Choose in oil (not water) to leverage fat for satiety and smoother blood sugar.
  • Heads-up: If you’ve been low-fat for years, your gallbladder might “complain” at first—like any deconditioned muscle, it adapts.
  • Outcome: Many people watch cravings drop, sleep steady, and fasting glucose improve—fast.

“How long should you wear a CGM? Until you trust yourself. The data changes habits.” — Dr. Boz

How to Read Your Numbers (Quick Guide)

(Educational only; not medical advice.)

  • Fasting (AM and pre-meal): Aim for double digits, ideally 70s–80s.
  • After normal meals:
    • ~30 minutes: ≤140 mg/dL
    • ~1 hour: <130 mg/dL
    • ~90 minutes: ≈110 mg/dL
    • ~2 hours: back near starting baseline
  • During/after workouts, a temporary bump is expected—especially with big-muscle work or hard cardio. Focus on the return to baseline.

The Big Takeaway

  • Cardio sessions mobilize glucose to meet demand—that’s good.
  • Quality sleep is when deep repair happens; protect those hours 5–7.
  • Consider the Sardine Challenge if full fasting feels out of reach—whole-food protein + fat can reset satiety and stabilize glucose.
  • Use a CGM to learn your patterns; pair it with real-world habits (stress, heat, sleep, food, training).

Final Thoughts & What’s Next

Part 3 capped our quick-hit series with cardio + CGM and a powerful sleep/nutrition angle. We’re recording a podcast next to track what our sugars do during post-workout recovery—that’ll be a fun curve to watch.

LINKS for Dr Boz:
DexCom – Continuous Glucose Monitor

Dr Boz’ official website: https://bozmd.com/

Dr Boz YouTube channel: https://www.youtube.com/@DoctorBoz