I wouldn't say they kept pace. They exceeded it in certain areas (early space race being a prime example) but US Imperialism allowed them to overmatch the Soviets in lots of areas. The reality is that the Soviets were on the back foot almost the entirety of the cold war. Case: The whole "missile gap" bullshit about how the Soviets had more nukes. They had less the entire time the "missile gap" was being debated in the Eisenhower/Kennedy debates.

Capitalist propaganda always made the Soviets out to be bigger than they actually were as a means of painting them as aggressors-in-waiting, when the Soviets, having lost 22-27 million people in WWII, were actually insanely reluctant to start another war, especially a nuclear war. Reddit jerks itself off every few years remembering that time that WWIII was prevented by a Soviet radar officer who wasn't willing to give the call to launch the nukes based on his data alone. They were desperate to avoid another giant war. The much maligned Molotov-Ribbentrop pact was a bid to prevent or at least delay another war after the disastrous Winter War against Finland. Stalin sent entreaties to the British etc to align against the Nazis but they were rebuffed. The Soviets knew they couldn't fight the Nazis by themselves, and they didn't. The beds of thousands of American trucks and millions of cans of tinned beef enabled the Red Army to eventually stop and later stomp the fascists.

But to credit your post, the fact that the Soviets, having lost so much they still had to keep up rationing until the mid 1950s (iirc) and then managed to doggedly keep up in second place to the Capitalists says a lot about the strength of a planned economy.