The Science of Exercise for Women 40+: What to Prioritise (And What to Ignore)

What It Covers

Exercise physiologist Lauren Colenso joins The Proof to address why women 40+ feel frustrated with their fitness results. The episode cuts through conflicting online advice to establish evidence-based priorities: why resistance training outranks all other exercise modalities, what minimum effective doses actually look like, and how physiological changes during midlife interact with training outcomes across strength, bone density, and functional capacity.

Key Questions Answered

• •Minimum Effective Dose — Resistance Training: Two full-body resistance training sessions per week, each containing four movement patterns (horizontal push, horizontal pull, squat, hinge), with two to three hard sets per exercise at 10–12 reps, delivers most of the measurable health benefit. Research on postmenopausal women consistently uses this structure — roughly six to eight total sets per muscle group per week — to produce improvements in muscle strength and bone density. Starting here outperforms any more elaborate program that never gets done consistently.
• •Cardio Guidelines Decoded: The physical activity guidelines translate to approximately 75 minutes of vigorous cardio per week (running, structured classes at a 5–7 out of 10 effort) or 150 minutes of moderate intensity (brisk walking, elevated heart rate above 100 bpm). Most women doing formal cardio already hit the vigorous threshold, meaning total weekly exercise time for both buckets combined is roughly two to two-and-a-half hours — far less than most women assume is required to achieve meaningful cardiometabolic benefit.
• •Proximity to Failure Determines Results: The single most common training error among women is stopping sets too early with loads that are too light. A set is sufficiently challenging when reps visibly slow toward the end, focus is required throughout, and at least one to two minutes of rest is needed before repeating the same output. A practical self-test: perform an AMRAP (as many reps as possible) on a familiar exercise — most women discover they can do significantly more reps than their standard working sets suggest, revealing chronic underloading.
• •Steps vs. Structured Exercise Trade-off: The mortality benefit from daily steps plateaus sharply between 6,000 and 8,000 steps — additional steps beyond that threshold produce diminishing returns. For time-limited women, spending 30–45 minutes on formal resistance training or high-intensity cardio delivers greater health benefit than walking an extra hour to reach 10,000 steps. Intensity is the key variable: it compresses time requirements while preserving or exceeding the adaptations achievable through longer, lower-effort sessions.
• •Muscle Loss Consequences Are Functional, Not Just Aesthetic: Sarcopenia — age-related muscle loss — progressively compromises activities of daily living: carrying groceries, climbing stairs, rising from chairs, and fall recovery. Women spend roughly one-third of their lives in peri- and postmenopause, and those who enter that period without a resistance training base face compounded decline. Masters athletes and women who begin lifting in their 50s, 60s, and even 80s demonstrably gain strength and muscle, disproving the narrative that meaningful adaptation is no longer possible after midlife.
• •Progressive Overload Requires Program Patience: Switching programs every few weeks prevents the progressive overload needed to drive adaptation. Staying on the same four-exercise structure for a minimum of eight to twelve weeks allows measurable progress: the same load for more reps, or the same reps at a higher load. Tracking sets, reps, and weights — even temporarily — provides the reference point needed to confirm progression is occurring and removes the guesswork that leads women to underload or plateau without realizing it.
• •Muscle Gain and Fat Loss Require Separate Phases: Simultaneously pursuing aggressive fat loss and muscle hypertrophy produces suboptimal results in both directions. Building a meaningful muscle base requires eating at or near caloric maintenance — not a surplus, but not a sustained deficit either. Women who redistribute food more evenly across the day (rather than restricting heavily until evening) often find they are already near maintenance. Prioritizing a dedicated muscle-building phase first creates a stronger metabolic foundation from which body composition goals become more achievable later.