How Different Weights Affect Your Heart During Workouts
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Introduction
A new study published in the Journal of Clinical Hypertension explored how lifting different amounts of weight during workouts affects your heart and blood vessels. It looked at what happens inside our bodies when we use heavy weights for fewer reps versus lighter weights for more reps. The goal was to find out which method puts more stress on the heart and arteries.
The Study Setup
Researchers tested 11 healthy adults who regularly exercised. They did two types of resistance training sessions:
- High Load (HL): Heavy weights for fewer reps (4 repetitions).
- Moderate Load (ML): Lighter weights for more reps (12 repetitions).
In both sessions, participants did the same exercises—bench press and deadlift—with the same effort level, meaning they stopped only when they couldn’t do more reps.
What Was Measured?
The scientists measured how stiff the participants' arteries became after the workouts. They used tools that checked blood flow and pressure in key arteries. Stiffer arteries are a sign of more stress on the heart and can be a warning of future heart issues.
Key Findings
Surprisingly, lifting lighter weights for more reps (ML) caused a greater increase in arterial stiffness and higher heart rates right after exercise compared to the heavier weight session (HL). In other words, even though the weights were lighter, doing more reps made the heart and arteries work harder—at least temporarily.
They also found that the pressure in arteries increased more after the moderate load workout. This means your heart had to push harder to move blood around your body after lifting lighter weights many times.
Why Does This Happen?
Lifting lighter weights for more reps increases the time your muscles are under strain. This makes the heart pump more blood and raises blood pressure. It may also trigger more nerve activity and stress in the cardiovascular system, especially during recovery.
On the other hand, heavier weights with fewer reps seem to stress the muscles more, but not the heart and arteries as much—at least right after the workout.
What This Means for You
If you’re lifting weights to build strength or improve your health, it’s important to know how your workout affects your heart—not just your muscles. This study suggests that using heavier weights with fewer reps may be safer for your heart in the short term, especially for people with heart concerns.
Conclusion
This study shows that workouts using lighter weights for more reps might put more stress on your heart and arteries than heavier weights with fewer reps. If you're concerned about heart health, consider working with a fitness professional to find the right balance for your training goals. Always listen to your body and talk to your doctor before starting any new exercise program—especially if you have heart problems.