Fall Base Plan 400/800

1:56.03 @ USATF Youth Nationals in the Final
Relay Split from NON actually came out at 1:53.8 on the website. Also ran 49.65 pr at USATF Youth Nationals still bummed that it is not dropping like my 800. This week I have the 2,4, and 8 at Russel E Blunt. I have a feeling my 200 will be sub 22. I just dont understand why I havent run faster in the 400 am I missing specific endurance, i have started adding the 6x200 at last 200m pace is there anything else i can do for 400m specific endurance and not just generalized speed endurance

1:56.03 @ USATF Youth Nationals in the Final
Relay Split from NON actually came out at 1:53.8 on the website. Also ran 49.65 pr at USATF Youth Nationals still bummed that it is not dropping like my 800. This week I have the 2,4, and 8 at Russel E Blunt. I have a feeling my 200 will be sub 22. I just dont understand why I havent run faster in the 400 am I missing specific endurance, i have started adding the 6x200 at last 200m pace is there anything else i can do for 400m specific endurance and not just generalized speed endurance