(Cardio is Hardio)
Dr. Stacy Sims, a prominent exercise physiologist specializing in female physiology, argues that the traditional “150 minutes of moderate cardio” advice is actually counterproductive for middle-aged women (perimenopause and menopause). This is your steady paced fitness class.
According to Dr. Sims, hormonal shifts (specifically the decline of estrogen) make women more sensitive to cortisol. Long, steady-state cardio (like 45-minute jogs or spin classes) can spike cortisol levels, leading to muscle breakdown and increased belly fat storage.
Instead, she recommends a “Polarized” approach: very high intensity or very low intensity, with almost nothing in the middle. We will also include an intentional Parasympathetic breathe exercise as a part of our stretch routine.
This Week’s Challenge
This week’s challenge is to add 2 short, intense cardio sessions. Do not do them while fasting!
While fasted cardio might work for men, it is often disastrous for women in perimenopause.
- The Mechanism: Training in a fasted state signals to the brain that the body is in a “resource-scarcity” mode, which spikes cortisol to mobilize energy.
- The Fix: Eat 15–20g of protein (and a bit of carbohydrate) before you work out. This signals to your hypothalamus that you are in a “fed state,” keeping cortisol levels significantly lower during the session. Make sure you give yourself enough time to digest before working out.
1. High-Intensity Interval Training (HIIT)
Dr. Sims recommends “True HIIT” to provide the stimulus that estrogen used to provide. This helps with insulin sensitivity and maintaining lean muscle. This is the style we have done in class.
- Frequency: 1 time per week.
- The Format: Short bursts of near-maximal effort (80–90% of your max) followed by recovery.
- Total Duration: 30 minutes (including warm-up and cool-down).
- Format: 5 rounds of 2 minutes at high intensity followed by 2 minutes of easy recovery.
2. Sprint Interval Training (SIT)
SIT is even more effective at burning visceral fat and improving brain health.
- Frequency: 1 time per week (can alternate with HIIT).
- The Format: “All-out” maximal effort for very short durations.
- Duration: 30 seconds of 100% effort, followed by a long, full recovery (3 minutes).
- Format: 4–5 rounds of 30-second sprints on a bike or uphill, with 3 minutes of recovery
3. Use Post-Workout “Nervous System Brakes”
After a workout, your sympathetic nervous system (fight or flight) is amped up. If you jump straight into school drop-offs or work meetings, your cortisol stays peaked.
- The Action: Spend 2–5 minutes immediately after your workout doing “Box Breathing” or lying with your legs up the wall. This manually flips the switch to the parasympathetic (rest and digest) nervous system, effectively “shutting off” the exercise-induced cortisol response.