Debunking the Interference Effect
For years, a persistent rumour has circulated in gyms across the UK: if you want to build muscle, you must avoid cardio at all costs. The fear is that performing aerobic exercise will trigger an 'interference effect,' essentially cancelling out the hard work you put into your strength training. At Clarence Park Health Suite, we often hear members express concern that adding a few minutes on the treadmill or rower will shrink their muscles or stall their progress.
However, recent scientific evidence suggests it is time to put this myth to rest. A study published in the Journal of Applied Physiology in early 2026 has provided compelling data showing that concurrent training—the practice of combining resistance training and cardio in the same programme—does not impair muscle protein synthesis or hypertrophy [1, 6, 9].
What the Science Says
The 2026 research specifically examined the impact of long-interval High-Intensity Interval Training (HIIT) alongside resistance training [1, 9]. The findings were clear: while those focusing solely on weights might see slightly different strength adaptations, the concurrent training group saw significant improvements in their VO2 peak (a key marker of cardiovascular fitness) without sacrificing muscle growth [1].
Essentially, your body is more adaptable than we once thought. The 'interference' that researchers worried about decades ago is largely irrelevant for the average gym-goer. Whether you are training for fat loss, muscle maintenance, or general health, you do not need to choose between being strong and having a healthy heart [3].
Practical Application for Your Gym Routine
If you are a member here at our Malvern gym, you might be wondering how to structure your sessions to get the best of both worlds. Here is how you can apply this research to your own training:
- Prioritise Your Goal: If your primary focus is building maximum strength, perform your resistance training first when your energy levels are highest [2]. You can then finish with a moderate-intensity cardio session or a short HIIT interval to boost your heart health without compromising your lifting performance.
- Don't Fear the HIIT: The 2026 study confirms that even long-interval HIIT is compatible with muscle building [1, 6]. If you enjoy the challenge of the rower or the bike, feel free to incorporate these into your routine alongside your weight training sessions.
- Consistency Over Complexity: The most important factor is that you are moving regularly. Whether you prefer to do your cardio and weights on separate days or back-to-back, the 'interference' is negligible for most people [3].
Tailoring Your Approach
At Clarence Park Health Suite, we pride ourselves on providing a friendly, supportive environment where you can focus on your individual goals. If you are unsure how to balance your cardio and strength work, our personal training services are designed to help you create a bespoke plan that fits your lifestyle.
We understand that everyone’s body responds differently. By focusing on a balanced approach, you can improve your metabolic health, support your cardiovascular system, and continue to build the strength you desire [8, 10]. You don't need to sacrifice one for the other; you can have both.
Next time you are in the gym, feel free to head over to the cardio equipment after your lifting session with confidence. Your muscles are safe, and your heart will thank you for the extra effort.