It depends on your age, your diet, and how trained you are. If you already train regularly, you can push harder(a 25% increase in weight or time is really demanding). You don't want to injure yourself. Most trainers would recommend about a 10% increase in weight or time per week.
For example, if you can do a set of 100lb squats this week, try 110 lbs next week. If you can run 5Km this or 30 mins this week, try adding .5km or 3 mins.
If you use the 10 % rule, in 6 weeks you will be 60% stronger and faster.
Like Lutzie said, slow reps really helps. And like Alex said, vegetables- you need them to help metabolise protein, and process the wastes your body produces while exercising.
Finally, work hard but rest, too. If you don't sleep, or take rest days(work out one day, and REST the next) you'll over train- you wont give your body a chance to recover and build strength. If you are older, you need more recovery time. If you work in the physical trades, you especially need to rest. to follow a challenging training regime.
Good luck, and let us know how you are doing!
whatever workout your doing with your arms.. (say lifting) DO IT SLOW INSTEAD OF FAST, have alot of protein, and always increase your workout by a quarter of what you've done before..
say you did 100 push ups, next time do 125.
same goes with distance when your walking..
it would be easier to put a camel through the loop of a needle then to do that...you'll need a LOT of determination...i work out (some what) i can't do it at home, because i have no trainer to boss me aroundhaving a trainer helps immensely, you push yourself harder so that you don't seem weakback tot he point.....start doing push-ups, do 100, either straight through or in setsdo sit-ups, do them till you can't do any more, wait 5 min and go againget a broom, put it on your shoulders, wrap your arms around ittwist side to side 100-200 times, then twist to your toeseat right, stay away from junk food, eat plenty off meat, and plenty of pasta don't forget the veggies!rest 2-3 days, start again....increase you the amount of work you do every week