[4][5] Having competed in 64 International strongman competitions and winning 11 of them, Belsak is among the 20 most decorated strongmen of all time.

[1][8][2] He grew up in a family of cooks; his parents own a restaurant "Gostilna Belšak"[9] where he still occasionally works as an apprentice chef.

As his strength was increasing really fast, it soon became clear that he might be able to show some really decent results in a couple of years.

Almost immediately after starting to compete in strongman, Matjaž won the title of Slovenia's Strongest Man in 2014[8] and did it again in 2015[8] The contest was not held during the next two years.

His first strongman competition after the hip replacement was Slovenia's Strongest man 2022,[17] which he also won, just about a year after the surgery.

[40] Matjaž is 187 cm tall (6 ft 2 in)[10][2] and weighs around 150 kg (330 lbs)[10][8][2] during the competitive strongman season.