Is Zone 3 Training Bad

There is nothing inherently wrong about training in zone 3 so long as it is beneficial for your race goals. If you are racing in events that are longer than about 2 or 3 hours and shorter than about 6 or 7 hours you will spend a lot of time in zone 3.

What is the best heart rate to build muscle?

• at 70–80% of their heart rate reserve, which a person can calculate by subtracting their resting heart rate from their maximum heart rate.
• for 30–45 minutes at a time.
• on 4–5 days per week.

Is it bad to train in Zone 4?

Heart rate zone 4 is where the going gets tough. You’ll be breathing hard and working aerobically. If you train at this intensity, you’ll improve your speed endurance. Your body will get better at using carbohydrates for energy and you’ll be able to withstand higher levels of lactic acid in your blood for longer.