[1] After leaving secondary school, Puheloinen began his military career as a conscript in the Uudenmaan rakuunapataljoona in Lappeenranta, where he was trained as a reserve officer.

After the statutory service period, he entered the military officer-training institution Kadettikoulu, although he had been admitted to both Helsinki School of Economics and University of Tampere.

[3] In 1974, Puheloinen graduated as a lieutenant and started service as a regular officer in the Armoured Brigade (Finnish: Panssariprikaati).

[1] In 1978, Puheloinen was selected to participate with three other Finnish officers in the five-month "Tactical Commander Course of Motorized Infantry Troops" in Soviet Union.

After the command college, Puheloinen served for three years as an intelligence officer in the Finnish Defence Staff, specializing in eastern affairs.