The Scotland lock went over for a try in Saturday's 33-25 win over Leinster at Scotstoun
Talking to glasgowwarriors.org, Tim said: "It's been a good pre-season, but it's been really tough, the worst one in terms of I've done in ten or eleven in my career.
"It's put us in good stead. We went from strength to strength in the second half on Saturday which is testament to the strength and conditioning team that are here this year."
Saturday also marked the unveiling of Scotstoun's new artificial surface and, according to Tim, predictions that it speeds up the game are accurate.
"In training last Wednesday we managed to set our fastest time; there's a bit of a debate between the back three over who it was, but one of them clocked 35.5km per hour, which is pretty sharp.
"It's a quick surface alright. I played on one a whole year for Newcastle A and this is a more modern generation. It helps quick rugby and it helps scrummaging as there's not much slip.
"When I last played on one for a full season it didn't feel harder on the body, you just felt different muscles.
"Our speed is really good now as is our interplay between forwards and backs and I think we showed at times that our forwards aren't there to run into a brick wall, we can offload and use our footwork to get around defenders."