Combining resistance training with steady-state aerobic exercise in the so-called Zone 2 heart-rate range is the foundation of a longer, healthier life, according to board-certified internist Dr Farhan Abdullah. While genetics account for an estimated 25 per cent of lifespan variation, lifestyle choices – particularly how we move – are the more powerful determinant for the vast majority of people. Dr Abdullah, who practises in Southlake, Texas and holds additional certifications in functional medicine and hormone optimisation, argues that neither method works in isolation. “When progressive resistance training and Zone 2 cardio are done regularly together, you build a foundation for healthy ageing,” he said.
How resistance and Zone 2 cardio work together for healthy ageing
Resistance training, Dr Abdullah explained, is a potent tool for maintaining blood sugar regulation, warding off frailty and fostering metabolic well-being. Skeletal muscle functions as an endocrine organ, secreting signalling molecules called myokines that influence glucose control, inflammation and hormone production. Muscle contraction also enables glucose uptake without insulin, bypassing a pathway that becomes dysfunctional in metabolic disease. Resistance training stimulates muscle protein synthesis via the mTOR pathway and modulates multiple hallmarks of ageing. Dr Abdullah recommends training major muscle groups two to four times per week using progressive overload – gradually increasing weight, repetitions or intensity. A minimum of two full-body sessions per week is sufficient to yield benefits. Muscle mass and strength are strong predictors of longevity and functional ability in later years; grip strength, in particular, is a validated marker of longevity independent of physical activity level.
Zone 2 cardio – performed at 60–70 per cent of maximum heart rate, a pace at which conversation remains possible – drives mitochondrial biogenesis, enhancing cellular energy production and improving the body’s ability to utilise oxygen. Consistent Zone 2 training improves VO₂ max, a strong predictor of all-cause mortality, and also boosts insulin sensitivity, fat oxidation and reduces inflammation. The recommended dose is three to four sessions per week, each lasting 45–90 minutes. Dr Abdullah described Zone 2 training as low-risk and sustainable over decades. “Zone 2 cardio can increase the amount of mitochondria in your heart cells and improve your body’s ability to utilise oxygen,” he said.
Together, the two forms of exercise address complementary biological pathways. Resistance training builds and maintains the machinery of movement while regulating metabolism and inflammation; Zone 2 cardio builds the cellular power plants that fuel that machinery and optimises oxygen delivery. The hormonal response to resistance training includes elevations in anabolic hormones such as testosterone, growth hormone, insulin and IGF-1, all critical for muscle growth and remodelling. Short rest periods and heavy resistance can promote testosterone release. Conversely, catabolic hormones such as cortisol can rise with high-volume, short-rest sessions, potentially hindering recovery – a reminder that structure and progression matter.
HIIT: benefits and limitations
Despite the popularity of high-intensity interval training (HIIT), Dr Abdullah warned against relying on it as a complete solution for longevity. HIIT offers genuine advantages, including improved VO₂ max and enhanced insulin sensitivity. Some research indicates that HIIT can trigger cellular changes that boost muscle energy production in older adults and may even reverse signs of ageing at a cellular level. However, Dr Abdullah cautioned that “there may be nothing worse for someone trying to extend their lifespan than believing that high-intensity interval training alone is enough.” Overuse or incorrect application of HIIT, especially in individuals experiencing stress, can be detrimental. Studies suggest that while HIIT can improve quality of life and cardiorespiratory fitness, it does not necessarily lead to a longer life compared with moderate exercise. To avoid chronic inflammation and elevated cortisol levels, Dr Abdullah advises limiting true HIIT sessions to one to three times per week and prioritising rest.
The overlooked power of daily walking
Beyond structured gym sessions, the simple act of brisk walking each day delivers substantial health benefits that many overlook. Dr Abdullah noted that daily brisk walks can improve cardiovascular health by lowering blood pressure and reducing triglycerides. They also reduce visceral fat by burning off calories consumed after meals. Research suggests that as little as 15 minutes of brisk walking per day is associated with a nearly 20 per cent reduction in premature mortality. Even ten minutes of brisk walking daily could increase life expectancy by three years, particularly for individuals with multiple chronic conditions. Walking pace is recognised as a marker of overall health and can be a target for intervention. Accumulating short bouts of brisk walking throughout the day can be as effective as a continuous session in reducing postprandial triglyceride concentrations and resting blood pressure. Dr Abdullah also highlighted the role of walking in recovery between more intense workouts. “Many people complicate their workout routines and overlook how much of a benefit a lot of impact walking each day could provide towards extending one’s life span,” he said.
Dietary approaches that support longevity
Diet plays a pivotal role in healthy ageing and extending lifespan. Maintaining a healthy weight throughout life is crucial, and the types of fats, proteins and carbohydrates consumed matter more than the quantity. Adherence to healthy dietary patterns such as the Mediterranean diet – which emphasises nutrient-rich plant foods and limits red and processed meats – is associated with reduced mortality and extended life expectancy, independent of genetic predisposition. While caloric restriction can extend lifespan, research suggests that losing weight on such diets may not be beneficial and could even be detrimental for some individuals. Meal timing and alignment with the body’s natural circadian rhythm of feeding also appear to be important factors.
Dr Abdullah’s recommended weekly programme combines these elements: two to four days of resistance training focused on compound exercises, two to three days of Zone 2 cardio, and at least some form of daily low-intensity activity such as brisk walking. “One of the biggest mistakes people make is to view strength training as either optional or only aesthetically pleasing and therefore do it sporadically or without progression,” he said. His approach, grounded in more than a decade of clinical experience and academic appointments at UT Southwestern and the Texas College of Osteopathic Medicine, underscores that longevity is built not through a single workout regimen but through a carefully balanced combination of training methods sustained over time.