Sorry, I was a little vague. I have an event in a month and am trying to increase my maximum reps in pushups, situps, bench, cut my run-time down.
What I've been doing is a three minute exercise doing one-third my current max every minute as quickly as I can, then resting the rest of the minute. For the run time I'm working on sprints.
And as follow-up for everyone else (after WAY too long, sorry about that) I'm currently sitting at roughly 230 lbs and will call this my new starting point.
Gotcha. Sounds like an interesting event. It sounds like what you are doing is good. If your not improving like you want to, you can increase to 5 minutes still with the same number of reps that way you are totalling above your current max.
The other option is doing some tobatta exercises and not worrying so much about the total reps and more about pushing as hard as you can for the time. Traditionally, tobatta is 20 seconds of work followed by 10 seconds of rest. I like to do tobatta as 30 seconds of work and 20 seconds of rest. It just works better for me. Do that for five minutes with just pushups, take a 2-3 minute break and then do the same for 5 minutes of situps.
It's hard to do stuff like that for benching. Presumably the competition is how many reps of a certain weight. If so, you can train by just doing max sets of the weight or by using drop sets. I can only recommend drop sets of you have a spotter, but if you do then they can be great.
Basically put weight on the bar and do 10 reps, then (with as little rest as possible) drop about 20% of the weight and do 10 more reps. Drop another 20% and do a final set. Rest for 2-3 minutes, reset, and do it again. You should reach failure on either round 2 or 3 of the first set.
Example: put 3 10lb weights per side (total 105 lbs) each set drop 10 lbs per side (about 20% of total).
Your starting weight will be up to you. You could try the target weight of the competition but, depending on how many reps you can currently do of that, it might be too high for drop sets.
Drop sets require a little bit of math but can be very effective at building endurance and teaching your muscles to push to and through exhaustion.
For running, I am a big believer in interval sprint training. Push hard for the sprinting and allow yourself to rest during the not sprinting. Do it for a certain amount of time or a certain distance whichever you prefer. I usually do it for 10 minutes as part of my warmups.
Hope this helps!