Ageless Strength: How One Retired Nurse Is Beating Muscle Loss and Staying Fit for Life

Linda and her family on their annual ski trip

Linda is a 66-year-old retired nurse who has been athletic her whole life. Even as a nurse and a mother of two, she always made time to train for events such as marathons, cycling events, and triathlons, while enjoying skiing, hiking, and rowing adventures. She currently works out regularly with weights and does cardio workouts like running, hiking, and cycling. Recently, she has noticed she isn’t able to lift the same amount of weight as before, becomes fatigued more easily, and her running and cycling speed have declined. She wants to stay fit and healthy to enjoy annual family ski trips and summer cycling events. She wonders whether these declines are simply a result of aging and, if so, what steps she can take to counteract them. Perhaps tweaking her diet and workout routine would help, but she isn’t sure where to begin. Since it has been years since she worked with a personal trainer, she decides to enlist the help of Jake, a trainer she knows from her gym, to find out what changes she can make to address these issues.

Linda Meets with Jake

Jake reassures Linda that while aging does create changes in the body that impact workouts, there are many steps she can take to slow these changes and even make improvements. He explains that muscle mass loss is a natural part of aging, beginning around age 50 and accelerating after 60, with up to 50% of muscle fibers lost by age 80. This process, called sarcopenia, is influenced by declining hormone levels (including testosterone, estrogen, growth hormone, IGF-1, vitamin D, and cortisol), as well as neural, metabolic, and inflammatory changes. Their reduction disrupts the balance between muscle protein synthesis and degradation, leading to functional decline. In fact, postmenopausal estrogen decline accelerates sarcopenia, contributing to an annual loss of grip strength of 3-4% and decreases gait speed. Estrogen deficiency also increases intramuscular fat, further reducing strength and increasing frailty (Endo et al., 2020; Giovannini et al., 2018; Khan et al., 2023; Kostek et al., 2005; McArdle et al., 2023; Minamino et al., 2021; Nunes et al., 2022; Papadopoulou, 2020; Shu et al., 2023; Wilkinson et al., 2018).

Jake also explains that while older adults may experience limited muscle hypertrophy (increased muscle size), they can still gain strength through improved neuromuscular efficiency-the ability of muscles to recruit more motor units. This means strength can improve even if muscle size does not visibly increase, compensating for some age-related muscle fiber loss. For example, a 12-week resistance program can increase strength by 25–30% even without significant muscle growth. Even those starting after age 70 can see measurable gains (Faulkner et al., 2007).

Jake congratulates Linda on her motivation to stay fit as she ages and explains to her that as a senior athlete, she will exhibit markedly slower rates of muscle loss compared to her sedentary peers.

To increase Linda’s strength, Jake suggests she incorporate other modes of fitness into her workout, which include balance, flexibility, kinetic-chain alignment techniques, supersets, and proprioceptive training. These improve functional strength, allowing for greater strength gains and the ability to lift heavier weights (Burke et al., 2024). He encourages Linda to continue her cardio workouts, which bring her great joy and help her body use energy more efficiently, reducing fatigue during prolonged activity such as skiing (Elena et al., 2004). Sustained physical activity is associated with a 20–30% lower mortality rate, due to preserved cardiometabolic health and cognitive function (Bonilla et al., 2024).

When Linda asks about dietary changes, Jake explains that older adults experience "anabolic resistance," meaning they require more protein to stimulate muscle protein synthesis compared to younger individuals. Studies recommend a protein intake between 1.2 and 2.0 g/kg/day for older adults, especially those participating in strength training. Studies on older adults (65+) who consumed 1.2-1.6 grams of protein per kg of body weight per day while also participating in strength training show a small but meaningful increase in muscle tissue. It is advisable not to exceed 2.0 g per kg of body weight per day (Baum et al., 2016). Since chronic inflammation can also impede muscle response to training, Jake suggests including anti-inflammatory foods such as fatty fish (rich in omega-3 fatty acids) to support muscle health (Doussat et al., 2024).

Jake emphasizes that the quality and type of protein matter, especially since older adults often eat less overall. He informs Linda that metabolic rates remain stable from age 20 to 60 but decline by about 0.7% per year after age 60 (Pontzer et al., 2021). Plant proteins require a higher calorie intake to meet essential amino acid needs compared to animal proteins, so choosing lean animal protein sources can help avoid unwanted weight gain (Baum et al., 2016).

Linda tells Jake she has read not to consume more than about 30 grams of protein per meal, otherwise it just turns to fat if not used right away to build muscle. Jake responds that eating more protein than your body needs will not automatically turn the extra protein into fat. Extra protein is more likely to be used for energy, help build lean tissue, or be excreted, unless you are consistently eating more total calories than you burn-at which point, any macronutrient can contribute to fat gain. Increased lean muscle mass from higher protein intake supports a higher metabolism, better fat-burning, improved insulin sensitivity, stronger immunity, healthier aging, better bone density, and improved mental health. He tells her to focus on high-quality protein sources like meat, fish, and eggs that are rich in leucine, an amino acid critical for triggering muscle growth (Antonio et al., 2024; Puddick et al., 2025).

Jake advises Linda to discuss any dietary changes with her doctor.

Regarding supplements, vitamin D levels decline with age, and older adults have a significantly reduced capacity for vitamin D production compared to younger individuals, with studies showing up to a 50–60% reduction by age 70, and some sources noting as much as a 4-fold decrease in certain contexts (Chalcraft et al., as cited in Lips et al., 2022). Low levels are linked to muscle loss (Dzik & Kaczor, 2019) with several studies finding that vitamin D3 supplementation in the elderly results in increased muscle strength as well as reduction in falls and fractures when combined with calcium (Endo, Nourmahnad, & Sinha, 2020).

Jake suggests Linda discuss vitamin D testing and supplementation with her doctor.

Hydration plays a crucial role when increasing protein intake because higher protein consumption produces more nitrogenous waste products, such as urea, which the kidneys must eliminate (Knight et al., 2020). Adequate fluid intake supports kidney function by facilitating the excretion of these waste products and reducing the risk of renal strain (Knight et al., 2020; Hannah Eden Fitness, 2023). A practical guideline is to consume at least 2–3 liters (8–12 cups) of water daily, increasing to 3–4 liters if protein intake is elevated, with some recommendations suggesting an additional 500 mL to 1 liter of water for every 50 grams of protein consumed (Hannah Eden Fitness, 2023). However, excessive water intake can lead to hyponatremia, a dangerous condition characterized by low blood sodium levels, which can cause neurological symptoms. Adding electrolytes (with sodium) to plain water will help to prevent hyponatremia, but it is still important not to drink to excess. Balance is important (Mandic, 2023). To maintain proper hydration before exercise, it is advised to drink approximately 5–7 mL of water per kilogram of body weight at least 4 hours prior, and to include electrolytes during prolonged or hot workouts to replace sodium lost through sweat (Sawka et al., 2007).

Putting the Plan Together

Her meeting with Jake helped Linda make the changes she needed to reach her goals. He designed a fitness program that helped her meet her goals of increasing the weights she is able to lift and improve her stamina. To avoid unnecessary weight gain, while improving strength, she replaced some high-fat and high-carbohydrate foods with lean protein sources, increasing her protein intake to 1.5–1.7 grams/kg/day. She plans to maintain her fruit and vegetable intake and will consult her doctor about vitamin D levels and supplementation, kidney function, and her new diet plan.

Follow-up

Six months later, Linda checks in with Jake and is happy to report steady increases in the amount of weight she can lift, more energy, and stable weight. She looks forward to many more years of skiing with her kids, participating in local cycling events, and living the active life she loves.

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