For years, conversations about heart health in fitness have leaned heavily towards cardio workouts. Step counts, heart rate zones, weekly mileage & aerobic capacity are all terms you will have heard when discussing the cardiovascular system. Strength training on the other hand, often sits to one side, framed as something you do for muscles, bone density or aesthetics, rather than for the heart itself.
But some very interesting research is starting to make that view look increasingly outdated.
Recent research is showing that resistance training doesn’t just place a demand on the cardiovascular system in the moment. It sends signals that influence how heart-related genes behave over time. That’s not by changing DNA, but by altering how certain genes are regulated, expressed and remembered. This is all down to epigenetics, and it helps explain why lifting weights plays a much bigger role in long-term cardiovascular health than it’s often given credit for.
This article looks at what that actually means in practice, why strength training is not a threat to heart health, and how coaches can think about resistance work as a genuine cardiovascular input rather than a separate category of training.
Heart Health
Most people associate heart health with steady, continuous movement like walking, jogging, cycling, swimming etc. These are important and the evidence behind them is well documented. The problem is that this narrow framing leaves resistance training being seen as optional or even questionable for certain populations when it comes to heart health.
That idea usually comes from superficial observations. Lifting weights increases blood pressure temporarily. Heavy efforts raise heart rate. There’s strain, bracing and short bursts of effort. For someone looking in from the outside, it can seem aggressive rather than protective.
What’s often missed is the difference between short-term physiological responses and long-term biological adaptation. The cardiovascular system doesn’t judge exercise by how uncomfortable it feels in the moment. It responds to patterns, repetition and recovery. Over time, those patterns are what makes a difference and encourages body-wide improvements.
Understanding how all this works requires stepping away from traditional fitness metrics and looking at what’s happening at a molecular level.
Genetic Effects
When people hear the word genetics, it often sounds like something that’s fixed and unchangeable. Eye colour, height potential, inherited risk factors are all things we see as “genetics” and can’t be changed. But that’s not what this discussion is about.
Epigenetics refers to mechanisms that influence how genes behave without altering the DNA sequence itself. While genes stay the same, the way they’re expressed changes. Gene expression are the body’s switches or levers which adjust how weak or strongly certain instructions are followed inside cells.
The fascinating thing is, exercise is one of the strongest epigenetic signals the body receives. Repeated physical stress followed by recovery tells cells what to prioritise. Over time, that information shapes how tissues behave at rest, how they respond to future stress and how resilient they become.
Strength training sends a very specific type of signal. It involves mechanical tension, pressure changes, metabolic demand and neural involvement. The heart, lungs and blood vessels are all part of that conversation, not spectators.
How Strength Training Communicates With The Heart
When we perform resistance training, there are short, controlled increases in cardiac workload. Blood pressure rises briefly during lifts. Cardiac output adjusts to meet demand. These responses are expected and transient.
From a biological perspective, that intermittent loading has an effect. The heart experiences a stimulus, adapts, then returns to baseline. Over repeated sessions, this pattern leads to structural and functional adjustments that support efficiency rather than strain.
This type of stress differs fundamentally from the chronic overload seen in cardiovascular disease. In disease states, elevated pressure or volume persists without relief. In training, the load is applied, removed and followed by recovery. As we all know, it’s in recovery that improvements are made. This clear distinction between the states during resistance training and cardiovascular disease is he key difference between adaptation and damage.
Physiological Vs Pathological Cardiac Hypertrophy
Another thing that tends to raise eyebrows when talking about the heart is hypertrophy. Raising an eyebrow makes sense when hypertrophy is linked to disease. But shouldn’t be when discussing training adaptations.
Physiological cardiac hypertrophy refers to an increase in heart muscle size that preserves or improves function. Wall thickness increases in a coordinated way. Chamber dimensions remain appropriate. Contractile performance is maintained. Relaxation stays efficient.
Pathological hypertrophy tells a different story. Structural changes become disorganised. Fibrosis increases. Diastolic function deteriorates. Energy efficiency drops.
Research shows that resistance training, when programmed sensibly, aligns more with the physiological end of that spectrum. The heart adapts to manage intermittent pressure demands more effectively. These changes remain reversible and responsive to training load, which is a hallmark of healthy adaptation.
This is something we must all keep in mind, especially when working with clients who have concerns about lifting and heart health.
Heart-Related Gene Behaviour
A review by Silva and colleagues (2026) brings together evidence showing that resistance training influences epigenetic mechanisms linked to cardiovascular function. These effects appear across several regulatory pathways including:
DNA Methylation And Long-Term Regulation
DNA methylation affects how accessible certain genes are for transcription, which is the process where a cell reads genetic instructions and copies them into messenger RNA so they can be used. When a gene is easy to access, it gets read more often. When access is restricted, that gene becomes quieter, even though it is still present.
Exercise has been shown to influence these methylation patterns, particularly in genes linked to inflammation, energy metabolism and mitochondrial function. Over repeated training sessions, resistance training provides a consistent signal that nudges these genes towards patterns associated with healthier cardiovascular and metabolic function.
As these methylation patterns shift, they support improved blood vessel function, better control of blood sugar, and lower background inflammation. Importantly, these changes do not disappear the moment training volume drops. Because methylation acts as a form of long-term regulation, some adaptations persist beyond active training phases, which helps explain why improvements in blood pressure and insulin sensitivity can remain even when sessions become less frequent.
This idea of biological memory is especially relevant in coaching. It explains why periods of inconsistent training are not “wasted time” and why clients often regain fitness and health markers more quickly after returning to structured resistance training.
Histone Modifications And Gene Accessibility
Histones help organise DNA inside the cell nucleus by wrapping and packing it into a form the cell can manage. How tightly DNA is wrapped around these histones determines how easy it is for certain genes to be accessed and read.
Exercise, including resistance training, influences this packaging process through chemical changes known as histone acetylation. These changes loosen specific sections of DNA, making genes involved in energy production, stress management, and cellular maintenance easier to access when they are needed.
In cardiac tissue, this supports healthier mitochondrial behaviour and a more efficient response to the physical demands placed on the heart during training. Importantly, these histone-related adaptations remain flexible rather than permanent, reinforcing the idea that regular training guides cardiac function without locking the heart into rigid or pathological patterns.
MicroRNAs and Fine-Tuning Adaptation
MicroRNAs act as regulatory messengers that help fine-tune how much of a given protein is produced inside a cell. Rather than switching genes on or off, they adjust the volume, ensuring that proteins are made in the right amounts and at the right time.
Resistance training has been shown to influence several microRNAs linked to cardiac contraction, calcium handling and metabolic efficiency. As training exposure accumulates, shifts in microRNA expression help guide the heart towards coordinated, efficient function rather than excessive growth or stiffness.
These changes play an important role in distinguishing healthy, training-induced adaptation from the patterns seen in cardiovascular disease. They also support better communication between skeletal muscle, blood vessels and the heart, helping the whole system respond more smoothly to physical load. At this level of regulation, it becomes clear that strength training influences far more than the tissues directly involved in lifting the weight.
Weights and Cardiovascular Risk
Concerns about blood pressure during lifting usually centre on what happens in the moment. During a heavy set, blood pressure rises and the heart works harder to meet the immediate demand. Those acute responses are real, they happen, but they are also brief, controlled and an expected part of the stimulus that drives adaptation.
But it’s this adaption that’s important. Over time, regular resistance training results in lower resting blood pressure, improved endothelial function and better autonomic regulation of heart rate and vascular tone. All of this results in a reduction to the constant, regular strain from cardiovascular disease. Structured exposure to resistance training improves the systems ability to respond to physical and psychological stress.
If you’re a strength and conditioning coach already, you will no doubt have seen this working with your existing clients. Clients who train consistently tend to recover more quickly between sessions, cope better with daily demands and show steady improvements in baseline health markers. These changes reflect adaptation, not accumulation of stress.
Understanding the difference between short-term exposure and long-term adaptation allows us to explain resistance training with confidence. It provides a clear framework for reassuring cautious clients and for communicating effectively with healthcare professionals who may still associate weight training with cardiovascular risk rather than resilience.
Programming Implications
Epigenetic adaptations do not respond to single workouts in isolation. They respond to patterns that are repeated over time. When training is inconsistent or programming is random and unstructured, the signals reaching the body are mixed and short-lived. When training is structured, those signals become clear and predictable, allowing longer-term biological adaptation to take place.
From that perspective, progressive overload, adequate recovery, and regular exposure matter far more than chasing maximal intensity. Moderate resistance training performed consistently provides a strong enough stimulus to influence cardiovascular regulation without placing unnecessary strain on the system. The heart, blood vessels and metabolic pathways adapt because they are exposed to manageable demands again and again, not because they are pushed to extremes.
This is also why resistance training works best when it sits alongside aerobic work rather than replacing it. Each training modality sends slightly different signals, shaping different aspects of cardiovascular health. Together, they reinforce one another, creating a broader and more resilient adaptive response across the whole system.
This way of thinking fits naturally with how modern education frameworks within personal trainer courses increasingly approach health. The focus shifts away from isolated fitness qualities and towards long-term physiological resilience built through thoughtful, repeatable training structure.
Explaining Heart Benefits To Clients Without he Science Lecture
Most clients don’t need a breakdown of molecular pathways to feel confident in their training. What they need is reassurance and a clear understanding that the work they are doing is genuinely supporting their health. When strength training is explained in simple, grounded terms, it becomes easier for clients to trust the process and stay consistent.
Messaging can be as simple as: At its core, resistance training helps the heart work more efficiently. It improves how blood vessels respond to physical demands, supports long-term blood pressure control and leaves lasting biological signals that continue to support cardiovascular health between sessions. These are quiet, behind-the-scenes adaptations, but they matter far more than what happens during a single workout.
This way of framing strength training resonates particularly well with older adults, clients managing hypertension and people who feel uncertain or nervous about lifting weights. Clear, confident explanations reduce anxiety, build trust and encourage long-term engagement. For coaches, especially those working through a pt course or supporting newer trainers as they develop their communication skills, the ability to explain why training matters can be just as important as the programme itself.
The Long-Term Role Of Strength Training in Cardiovascular Health
A client’s training history is important because the body responds to what it experiences repeatedly, not to isolated sessions. Regular exposure to resistance training leaves a biological imprint that shapes how the cardiovascular system copes with future physical and psychological stress. Over time, the heart and blood vessels become better at responding efficiently rather than reacting defensively.
Beginning strength training earlier in life simply gives that adaptive process more time to develop, but meaningful benefits are not limited to early starters. Introducing resistance training later still supports improved cardiovascular function, better stress tolerance and long-term protection. These adaptations accumulate gradually and continue to contribute to health across the lifespan.
This way of viewing strength training reflects a broader shift in how the discipline is understood. Resistance work is increasingly recognised as a foundational health input, supporting cardiovascular resilience alongside physical capacity, rather than sitting solely in the realm of performance-focused training.
Final thoughts
As you can see, strength training influences the heart at levels most people never see. Through epigenetic regulation, it shapes gene behaviour linked to metabolism, inflammation, vascular function and cardiac efficiency.
The idea that lifting weights threatens heart health is an outdated thought that doesn’t hold up under scrutiny. When programmed and progressed sensibly, resistance training supports cardiovascular resilience rather than undermining it.
For us as coaches, this reinforces an important message. The work done in the gym extends well beyond muscle. Every structured session contributes to long-term biological adaptation, including in the heart itself.
Reference
- Silva, J. G., Rodrigues, L. F., Torres, T., Improta-Caria, A. C., Oliveira, E. M., & Fernandes, T. (2026). Resistance training and cardiovascular health: epigenetic regulation. Frontiers in Physiology, 16, 1701689. Click here to review the full research article.
- Paluch, A. E., Boyer, W. R., Franklin, B. A., et al. (2024). Resistance exercise training in individuals with and without cardiovascular disease: A scientific statement from the American Heart Association. Circulation, 149(3), E217–E231. Click here to review the full research article.
- Liu, Y., Lee, D. C., Li, Y., et al. (2019). Associations of resistance exercise with cardiovascular disease morbidity and mortality. Medicine & Science in Sports & Exercise, 51(3), 499–508. Click here to review the full research article.
- Fernandes, T., Soci, U. P. R., & Oliveira, E. M. (2011). Eccentric and concentric cardiac hypertrophy induced by exercise training: MicroRNAs and molecular determinants. Brazilian Journal of Medical and Biological Research, 44, 836–847. Click here to review the full research article.
- McGee, S. L., Fairlie, E., Garnham, A. P., & Hargreaves, M. (2009). Exercise-induced histone modifications in human skeletal muscle. Journal of Physiology, 587(24), 5951–5958. Click here to review the full research article.
Strength Training, Heart Health, and Modern Coaching
The Strength & Conditioning Specialist & Master Diplomas™ reflect the growing evidence that resistance training supports cardiovascular health, with research showing that 2–3 structured strength sessions per week can lower resting blood pressure and improve vascular function. They’re designed for coaches who want to programme strength with long-term health and performance in mind, not just short-term gains.
