Is there a lot of combat and physical training during AIT for 35M?

No. There is not. It's focused on intelligence and the coursework is rigorous, but it's not particularly physically demanding as compared to say combat arms. It's more demanding than say 92A school.

Job training for a human intelligence collector involves 10 weeks of Basic Combat Training and 20 weeks of Advanced Individual Training with on-the-job instruction at Fort Huachuca, Arizona. This time is divided between the classroom and the field.

AIT's are generally the same. You will have physical fitness at least M-F, followed by classroom time learning your MOS. Fitness training while in the field will depend on the instructors and the class schedule. Because your MOS is in the Medium physical requirement category, I doubt you will be doing much fitness training beyond the normal daily training.