Slow SSL handshake

I am running a haproxy with multiple backend with SSL.
One backend is used for connecting an external rest api over SSL(https). So for each api call the connection validating 2 ssl handshake (first handshake between user and haproxy server, second handshake between haproxy and api server )which increasing the response time. I tested the same over http it is working fine and response time also very less.
there is any way to fine tune the haproxy backend server ssl handshake. How rest api is called over haproxy with ssl

Use http-reuse and make sure to also configure pool- settings.