cardio has went downhill since weight traing

[goldenbolls]

i used to do at least a 40-50 minute run in gym 5 days per week at 7.3 mph non stop. now i have started lifting heavy weights after my running, i now do 30 minutes running then go onto to do around 45 minutes upwards of heavy weight lifting . i was talking to an old timer in the gym ( ex boxer) and weightlifter, he told me that my cardio would go downhill and get harder to run since ive introduced weight training to my regime ? i have known now that im out of breath after running 30 mins non stop, it used to be that i could just float along but now there is a definate change.

anyone else feel this ? why is this ? also its been 5 weeks now since weight training, i can notice tightening up but no real gains ? i want big on top but i also want to keep my fat off as i have struggled with fat all my life, i love a beer at weekends ( i know i know !! tut tut )

[Bigeye74]

You should concentrate on you fitness rather than running at a certain pace. Slow right down and run longer. Also try a heart rate monitor to show you where you are going wrong with your pace.
Keep up the weights!