The frontman visited the same centre in Los Angeles as he did last year when recovering from a knee injury.
"It was a case of me going out and getting some dedicated strength training." he said. "It was just off my own back.
"I went out there and trained hard for three weeks and got more strength and stability, not only into my leg, but into my upper body. You get two one-on-one sessions a day. It's just a change of scenery and different philosophies."
The former QPR man, whose goals towards the end of last season helped to ensure Forest's Championship survival, revealed that he had been training with a number of elite sportsmen.
"When I'm there I'm training with a lot of top athletes from different sports." he said. "I was training with NBA star Derek Rose who got a knee injury playing for the Chicago Bulls.
"There was some top NFL players, some Premier League players - it's just a case of going away and seeing different cultures and styles. It's put me in great stead for this season."
On the other side of the Atlantic, a turbulent summer was being played out - but Blackstock is happy with how things have panned out.
"There have been many changes - a lot for the better. We've got new owners who have brought a bit of stability to the club, which is great.
"The players are buzzing and can't wait to start the league now."
to watch the full interview on Forest Player.