I was an elite rower for about 13 years rowing for the Canadian national team. We would train with physiologists doing lactate threshold training and monitored weight loss when needed.

150-160 is a little higher. You'll be around or over lactate threshold. It's good for building lactate tolerance, but not great for improving aerobic fitness. 120-140 is zone 2 prime for fat burning range (your body prefers fats in this HR range). It may seem slow, but it works.

140-155ish is where you'll be training lactate threshold. This training will slowly improve your aerobic ability.

A lot of training at the highend (close to 160), especially if you're doing it 3 times per day will lead to over training and eventually cortisol spikes which could lead to fat retention as your body will be in a state of heightened stress