Cardio and Strength Training: Do You Need Both?

What Each Type of Exercise Actually Does

Cardiovascular exercise — also called aerobic exercise — refers to sustained, rhythmic movement that raises your heart rate for an extended period. Walking, cycling, swimming, and jogging are common examples. During aerobic activity, your body uses oxygen to produce energy, which trains the heart and lungs to work more efficiently over time.

Strength training, sometimes called resistance training or weight training, involves working muscles against an opposing force — whether that's free weights, resistance bands, machines, or your own bodyweight. The goal is to create muscular stress that the body then repairs and adapts to, resulting in greater strength, muscle mass, and functional capacity.

These two modes of exercise trigger different physiological pathways. Cardio primarily improves cardiovascular efficiency — lowering resting heart rate, improving blood pressure regulation, and increasing the body's ability to use oxygen. Strength training primarily drives musculoskeletal adaptation — increasing muscle fiber size, strengthening tendons and ligaments, and stimulating bone-forming cells.

What the Evidence Says About Each

Decades of research have established robust health benefits for both exercise types. Regular aerobic activity is associated with reduced risk of cardiovascular disease, type 2 diabetes, and several cancers, as well as improvements in mood and cognitive function. The U.S. Department of Health and Human Services' Physical Activity Guidelines for Americans recommend at least 150 minutes of moderate-intensity aerobic activity per week for most adults.

The same guidelines also recommend muscle-strengthening activity on two or more days per week — reflecting growing evidence that strength training is independently associated with reduced all-cause mortality, better metabolic health, and lower risk of falls and fractures, particularly as adults age.

Importantly, the benefits of each are not fully interchangeable. A 2022 review published in the British Journal of Sports Medicine found that combining aerobic and muscle-strengthening activity was associated with greater reductions in mortality risk than either type alone — suggesting the two work in complementary rather than competing ways. As physical needs shift across adulthood, both forms of exercise continue to play important roles at every life stage.

Where the Trade-offs Appear

For most adults, the question isn't which to choose — it's how to fit both into a realistic weekly schedule. Time is the most common constraint. A practical approach is to identify activities that offer some overlap: circuit training, rowing, and certain group fitness formats can provide moderate aerobic stimulus alongside muscular work, though they don't fully replicate the adaptations of dedicated sessions in either domain.

Another consideration is recovery. Intense strength training sessions create microscopic muscle damage that requires rest to repair, while high-intensity cardio taxes the cardiovascular system and can contribute to fatigue if not balanced thoughtfully. Warm-up and cool-down phases become particularly valuable when switching between or combining exercise types in a single session.

For people managing specific health conditions or returning to exercise after a long break, the right balance of cardio and strength work may look different. A qualified healthcare professional or certified exercise physiologist can help tailor an approach suited to individual circumstances.

It's also worth noting that consistency tends to outperform intensity over the long term. Two moderate sessions of each type per week, maintained reliably, will produce better outcomes for most adults than sporadic intense efforts at either extreme.

Building a Routine That Includes Both

For adults who currently do little structured exercise, starting with one type and gradually adding the other is a reasonable approach. Walking is an accessible entry point for aerobic activity; bodyweight exercises such as squats and push-ups require no equipment and provide a foundation for strength work.

A straightforward weekly structure might look like: three days of moderate aerobic activity (such as brisk walking or cycling) and two days of full-body strength exercises targeting major muscle groups — legs, back, chest, shoulders, and core. Sessions don't need to be long; even 20–30 minutes of intentional effort provides measurable benefit.

If you find it difficult to maintain a routine, it may help to read about common patterns that derail exercise habits — recognising these early can help you course-correct before motivation fades entirely.

This article is for general informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before beginning a new exercise program, especially if you have an existing health condition or have been inactive for an extended period.