[00:00] I trained half my body with light weights and the other half with heavy weights for 60 days to see which one actually builds muscle faster. And the results? Not what I was expecting. The light side came with an insane pump,
[00:14] inflating my arm almost four times bigger than the heavy side. But pumps don't equal growth. So I got full body MRS scans to measure the growth of everything. I even found a beginner to do the experiment with me. Both sides did the same number of sets.
[00:28] Heavy meant 3-6 reps to failure, and light meant 15-30 reps to failure. After 60 days, the heavy side got way stronger, but my knees and elbows were begging me to stop. The light side built endurance, but every set was a mental battle to reach failure.
[00:43] But which side grew more? One muscle, a deep hip stabilizer, grew on my heavy side but actually shrunk on my light side. This imbalance might be why I tweaked my back during normal deadlifts after the experiment.
[00:55] But every other muscle we measured grew slightly more on the lighter side, likely because it did way more volume. Surprisingly, my chest had the biggest difference, twice the growth on the lighter side. Maybe because I've never trained it with such high reps.
[01:07] Dennis, the beginner, also grew slightly more on the lighter side. But the actual growth differences were tiny, sometimes just 15 grams, and definitely not visible in the mirror. At least I don't think. You guys tell me. But remember, there's a middle ground that I didn't test.
[01:21] 6 to 15 reps with moderate weight. And after doing this experiment, I honestly think that's the sweet spot for gains.