His main event was the javelin throw, in which he won the silver medal at both the 1932 Summer Olympics and the 1934 European Championships, but he was also a good pentathlete, breaking the unofficial world record in 1931.

[1] Sippala defeated javelin world record holder Matti Järvinen at the Finnish Olympic tryouts in 1932, throwing 70.02.

[2][3] In the sixth and final round Sippala threw 69.80 m, moving from fourth to second place as Finland swept the medals.

[1][2][4] At that year's European Championships in Turin he won another silver medal with 69.97 m, again behind Järvinen who broke his own world record.

[2] In the non-Olympic pentathlon, however, he won several national titles; at the 1931 Finnish championships he scored 4083 points and defeated Olympic decathlon champion Paavo Yrjölä in a close competition as both exceeded Martti Tolamo's unofficial world record of 4011.