How many sit ups and pushups should I be doing to improve my biking and running skills daily ....also ....what part of the body do push ups and situps improve the most.

Pushups work the arms and back about 70% and chest about 30% - if that.

Situps just cause lower back problems, they work back muscles, not stomach.

Various forms of the crunch actually target the stomach muscles.

I'd try to work up to 100 p/u's and 200 crunches a day. It will build core strength, which is good for any sport.

What is "the crunch" exactly?

In a crunch, you lay on your back and bring both your head and your legs up at the same time, using your abs. There are variations of it, but that is the basic version.

I do em by keeping my legs in the air, my thighs 90* with my abdomen, and bring my upper body forward to meet them. I also do some variations that work the sides more, things like that.

I do em in sets that last until they start to burn really bad. Then immediatly after I do some other thing where I lay flat on my bench with my legs hanging over the end, and lift them up using my abs and lower back. A little rest inbetween sets of these, and you'll feel lit

As for pushups, there's no room in my room to do any so I use dumbells and things like that to work out my back.

Or as Coach said, "Elbows to knees, the abdominal squeeze" then after a bunch of those we'd do the Dead Bug together, lying on our backs with our legs and arms sticking out at 45 degrees, until one person collapses then Coach tells them to get 'em back up, and we all have to keep 'em up longer for some reason...... I was like 89 lbs in my last year of HS and I ended up in this heavy doody PE class, what they should have given me was an extra lunch. (and money to pay for the extra lunch)

Sit-ups can do long term damage (as noted previously) unless you place your feet against a wall/door and keep roughly a 90-degree bend at the knee & hips. IMO sit-ups/crunches provide too little gain for the time spent.

I've done a modification for a several decades that builds far more muscle mass. It's done in a sitting position on a cable machine which has a station with a cable position at shoulder height. You just do a crunch with weight. I use 80 to 90 lbs.

If you work out at a gym, they'll have a different type of machine to do the same thing.

When I did wilderness canoeing, I'd do three sets of 12 twice a week. Now with a lot of cycling, I only do two sets about every 8 or 9 days. Core strength, which this exercise and push-ups are key components for me, is very important for all activities.

Al

Absolutely true! I love sit-ups, did at least 100 a night, but I never did crunches or back stretches.
Major, major ouch!
After throwing out my back reaching for a cup of coffee, it took 3 days before I could walk without appearing to have a corncob inserted in a particular body orifice and 3 weeks before I could move without pain.
After 4 months, I'm pretty much back to normal, but I do my crunches every day.
I continue to do my push-ups, but only 50 sit-ups a night.

Sit-ups: as many as you can provided you do not hurt your back. Overall it is a great exercise to strengthen your back.

Push-ups: 100 to 200 daily. If you have never done push-ups, do not despair at first you will find it hard to do 20 to 30 reps. Initially do them by multiple of 10 to 20. Pace yourself, too many people are doing them way too fast. Do them at a moderate speed and breathe deeply. Do them from a full arms extension down to touching the floor with your nose. In the same daily routine change your arms width to train different muscles. Increase your reps on a weekly basis. You will be amazed at how many you can do after just a month. Push-ups are probably the best exercise to strengthen your upper body (chest, shoulders and triceps).

Definatly true about the machine, its what I use in college. I'm not sure if the OP has access to one though; I know now that I'm not in college I don't. I just crunch until it kills.

I do 300 push ups a day. Sounds like alot, but I space them out by doing a couple sets here and a couple sets there. Before you know it, you've done your 300.

For abs, there is a machine at the gym that I use. Usually do 4 sets of 20.

I actually bought a cable-weight machine to get this and four other exercises that you can't do with free weights. We converted part of the house to a gym. Saves time and money over going to a gym.

Al

If you do the push ups correctly believe me you will feel it more in your chest. 100 slow and controlled reps and you too will feel the burn.

If you place your arms wider for push ups you will use more chest muscels and closer together more arms. After my ride i do 4 sets of 6 pullups 20 pushups and 35 sit ups. Do the sets as fast as you can, dont take breaks. For the situps i sit on a whatcha ma callit ball (stabalizer ball or workout ball jobby) and sit up from there much nicer on the back. Make sure you do pull ups they are good for ya.

I had to do them for a stupid long time, fast, while I was in the Navy.

Bootcamp pushup = 2 second up, 2 second down. It was a treat.

Bootcamp long count pushup = 30 second middle lockout with M1 carbine filled with cement on nuckles; down was 2 seconds with 2 seconds on the up to middle 30 second lockout. This was if you were good.

Avg. number of pushups a day (yes, I kept track in the psychological warfare that it really is) 2,500 on a weekday if people kept screwing up. 1,500 on a good day.

We love you Master Chief.

Up-downs were fun, as were hello dollies. I have added both back to my aerobic workout.

These were the equivilant to a beer, steak dinner and a few moments with our girlfriend/wives, dead cockroaches is what our CCs called them, and if you got to do the dead cockroach, someone else was getting their pain+ yours and you weren't let down for it by the company.