Summary
Personal trainer Kim Eagle does a detailed side-by-side comparison of sprint interval training (SIT) and high-intensity interval training (HIIT) for women navigating perimenopause and menopause. She defines SIT as 90-100% effort for 20-30 seconds with 2-4 minutes full recovery, versus HIIT at 80-90% effort for 30 seconds to 2 minutes with 15-60 seconds rest. Kim references a 2019 Journal of Physiology study showing postmenopausal women doing SIT three times weekly for two months saw major cardiovascular improvements. She emphasizes that training must shift with age, as cortisol is more easily triggered and recovery slows. She advocates for a mixed approach: one SIT session, one HIIT session, and 2-3 zone 2 cardio sessions per week, adjusted based on individual recovery and response.
Key Points
- SIT: 90-100% effort for 20-30 seconds, 2-4 minutes full recovery, 4-6 rounds, 15-20 min total
- HIIT: 80-90% effort for 30s-2min, 15-60 seconds rest, elevated HR throughout, 20-30 min total
- 2019 Journal of Physiology study: postmenopausal women doing SIT 3x/week for 2 months saw major cardiovascular and insulin sensitivity improvements
- SIT is best for VO2 max, performance, and fat oxidation; HIIT is better for building endurance
- If you can't recover within 4 minutes between SIT sprints, step back to HIIT first
- Too much HIIT or SIT triggers cortisol, stalls fat loss, disrupts sleep, and causes burnout
- Zone 2 training (60-70% max HR) is an underrated fat burner and hormone balancer for midlife women
- Recommended mix: 1 SIT + 1 HIIT + 2-3 zone 2 sessions per week, adjusted to individual recovery
Key Moments
Side-by-side comparison of SIT vs HIIT
Detailed comparison: SIT is 90-100% effort for 20-30s with 2-4 min full recovery; HIIT is 80-90% effort for 30s-2min with 15-60s rest. SIT produces heart rate spikes with full drops; HIIT keeps heart rate elevated throughout.
"When we talk about effort level I said hit is gonna be 80-90% effort. Sit is 90 to 100% all-out effort. In terms of interval duration,"
2019 study on postmenopausal women and SIT
A 2019 Journal of Physiology study found postmenopausal women doing SIT just three times per week for two months saw major cardiovascular improvements and improved insulin sensitivity.
"Now in 2019, there was a study published in the Journal of Physiology and they found that postmenopausal women doing SITS"
Why training must shift in perimenopause
As estrogen drops, muscle mass declines, belly fat increases, and recovery slows. Cortisol gets easily triggered by too much HIIT or SIT, stalling fat loss, disrupting sleep, and causing burnout.
"Your body is going to become much more sensitive to stress, and that absolutely includes workout stress. And cortisol gets easily triggered"
