Key Takeaways
- Cardio and strength training serve different but complementary roles in a balanced fitness routine.
- Your health goals — not a universal rule — should determine which type of exercise you prioritise first.
- Both forms of exercise provide significant health benefits, and most adults benefit from including both.
- Beginners can safely start with either type; proper form and gradual progression matter more than order.
- Current physical activity guidelines recommend adults include both aerobic and muscle-strengthening activity each week.
Option A
Cardio Training
The heart-health and endurance foundation.
Best for: People looking to improve cardiovascular health, build stamina, manage weight, or ease into regular exercise after a long break.
Option B
Strength Training
The muscle-building and metabolic booster.
Best for: People aiming to build muscle, improve bone density, boost resting metabolism, or maintain functional strength as they age.
If your primary goal is improving heart health or managing blood pressure
Cardio Training
Aerobic exercise directly trains the cardiovascular system, improving heart efficiency and circulation. It's well-established as a first-line physical intervention for cardiovascular health.
If you want to build functional strength, improve posture, or protect bone density
Strength Training
Resistance training stimulates muscle and bone adaptation, which is especially important for adults over 40 and those at risk of osteoporosis or muscle loss.
If you're returning to exercise after a long break and want to ease back in
Cardio Training
Low-to-moderate intensity cardio — like walking or cycling — offers a low-barrier entry point with minimal injury risk, helping rebuild the habit before adding load-bearing work.
If you have limited time and want the most metabolic impact per session
Strength Training
Muscle tissue increases your resting metabolic rate, meaning strength training continues to burn energy even after the session ends — a longer-lasting metabolic effect than steady-state cardio alone.
If you want to support long-term independence and quality of movement as you age
Strength Training
Research consistently links resistance training with better balance, reduced fall risk, and preserved functional capacity in older adults — making it a high-priority investment in healthy aging.
What Each Type of Exercise Actually Does
Before deciding which to prioritise, it helps to understand what each type of exercise trains — and why both matter.
Cardio training (also called aerobic exercise) includes any sustained activity that raises your heart rate: walking, running, cycling, swimming, or dancing. Its primary target is the cardiovascular and respiratory systems. Over time, regular cardio improves your heart's pumping efficiency, lowers resting heart rate, and enhances how well your muscles extract oxygen from blood. These adaptations reduce the risk of heart disease, support healthy blood pressure, and improve overall endurance.
Strength training (also called resistance training) involves working muscles against load — using bodyweight, free weights, resistance bands, or machines. The primary adaptations are muscular: muscle fibers thicken and recruit more efficiently, connective tissue strengthens, and bones become denser in response to mechanical stress. These changes support posture, balance, joint stability, and the ability to perform everyday tasks without fatigue or injury.
Neither form replaces the other. They develop distinct physical qualities that together form the foundation of good health. For a fuller look at how strength and flexibility work together, see our complete overview of strength and flexibility training.
| Criterion | Cardio Training | Strength Training |
|---|---|---|
| Primary system trained | Cardiovascular & respiratory | Muscular & skeletal |
| Key health benefits | Heart health, endurance, blood pressure | Muscle mass, bone density, metabolism |
| Calorie burn during session | Typically higher per minute | Typically lower per minute |
| Post-exercise calorie burn | Returns to baseline quickly | Elevated for hours after session |
| Injury risk for beginners | Low (especially walking/cycling) | Low-moderate with proper form |
| Equipment needed | Often none (walking, jogging) | Bodyweight to gym equipment |
| Supports healthy aging | Yes — heart and lung function | Yes — balance, bone, and muscle |
| Recommended weekly volume (US guidelines) | 150–300 min moderate intensity | 2+ days per week |
How to Choose Where to Start
The most honest answer is: it depends on your goals. There is no universal correct starting point, and the research does not support a single sequence that works for everyone. What matters most is choosing an approach you can sustain and progress safely.
Start with cardio if:
- Your doctor has flagged cardiovascular health as a priority
- You've been largely sedentary and need a gentle re-entry into movement
- Your main goal is building stamina, reducing stress, or supporting mental wellbeing
Start with strength if:
- You're over 40 and want to protect muscle and bone mass — both decline naturally with age
- Your daily life involves lifting, carrying, or physically demanding tasks
- You want to improve body composition by building lean muscle alongside fat loss
If you're new to resistance training entirely, our beginner's guide to strength training walks you through safe starting points and what to realistically expect. Before committing to a new programme, it's also worth running through our readiness checklist to confirm you're set up for sustainable progress.
2x/week
Minimum strength training frequency recommended
The U.S. Department of Health and Human Services Physical Activity Guidelines recommend muscle-strengthening activity on at least two days per week for adults.
3–8%
Muscle mass lost per decade after age 30
Research estimates adults lose approximately 3–8% of muscle mass per decade from their 30s onward, a process called sarcopenia, which strength training can help slow.
35%
Reduction in cardiovascular disease risk
Regular aerobic activity is associated with approximately a 35% reduction in cardiovascular disease risk, according to reviews cited in major public health literature.
This article is for general informational purposes only and does not constitute medical advice. Consult a qualified healthcare professional before starting any new exercise programme, especially if you have an existing health condition.