too long between strength training workouts?

What do you do for your buns workout? Wouldn't that be incorporated into the legs work out with squats and lunges and what not?

In general it's a good idea to train each major muscle group with a frequency of at least twice per week. Extending downtime beyond this leads to some "detraining."

For me, splitting it up into upper and lower bodies makes more sense.

I guess I am just confused because I read that in many ways a split routine is better,

You're over-thinking this, which is quite common.

Everything requires context when discussing this stuff. A split routine can't be compared to a full body routine without considering your goals, your training history, how close to your genetic strength potential you are, your schedule, etc, etc. You see, some things are better suited given the appropriate context. But nothing is better or worse on their own terms.

because it allows you to focus all of your energy on one muscle group.

That's a fine rational, but in truth, split routines were a product of the steroid error. Research has showed us that there's an optimal volume and frequency for both strength enhancement and hypertrophy (muscle growth).

Those routines that tell us to blast each muscle group with a lot of exercises disregards what we know about this optimal volume and frequency. There's a point of diminishing returns and unless you're using steroids, there's no point whatsoever in surpassing these points.

Our muscles respond to the stress of training by first decreasing its "state." It's like when someone is sick. Their state declines. Then their body responds by fighting off the sickness. More often than not, before all is said and done, their state actually reaches a point above and beyond what it was prior to their sickness. And this is the general stress-response mechanism of the body. Our bodies handle all stress (physical/mental/etc) similarly.

Now every factor of the body really responds on its own separate wave. What we're concerned about most in terms of muscle's response to training though tends to come back to baseline 2-3 days after you train. That's why the normal body building splits where you're hitting each muscle once per week are sort of silly. We want to build on top of what we already did previously, which would mean hitting that muscle again somewhere along the line where we're supercompensating above baseline. There are many different ways to structure "routines" to fit that time line.

But this is the rational behind my normal recommendations of training each part and/or movement 2-3 times a week with the basic exercises, focusing on something between 5 and 10 reps for 3-5 sets per exercise, and striving to improve your weights over time (not necessarily every workout).

It's pretty hard to go wrong with anything that falls into that realm.

I don't want to have big, bulky muscles, but I do want to tone up and have fairly visible muscles.

There's no such thing as bulking up while you're in a caloric deficit. Building muscle requires a lot of energy (calories) and if you're not eating enough to maintain your current tissues... you're not going to be able to add a metabolically active tissue like muscle. At least not to any degree where you'd consider it "bulking up."

Becoming lean or toned is a function of losing fat while maintaining muscle. We know what it takes to lose fat - a caloric deficit which is accomplished from eating less food than your body needs and supplementing that with some metabolic (cardio) training.

But what does it take to maintain muscle while trying to lean out?

Adequate protein consumption and appropriately structured weight lifting.

I just can't seem to get a routine that lets me work the muscle groups consistently, without too much time in between.

I'm going to email you something that I think would help you. Read it and if you have specific questions, ask them here so everyone isn't left in the dark.

Here is what I would do. If you do cardio like running then that can be your lower body workout. To build lower body strength you can just run on an incline one of the 3 days of the week you go to the gym. You get your cardio and your lower strength training in one shot. Then I would do upper the other 2 days of the week. Never do the same body parts two days in a row. Your mucles need at least a day to rest.

Unless you're very untrained... cardio isn't going to provide a strength/growth response to the muscles.

Thank you stroutman! I haven't received a message from you yet.. but I was wondering, when I am doing machines at the gym, they instruct us to do 8-12 reps (one set) with momentary muscular failure. When I do something like free weights, I do sets of reps. Does this sound right?

You don't want to be training to failure. There are very few instances where training to failure is beneficial. When it comes to enhancing body composition via exercise, it's almost pointless.

I'm already junking up this thread with enough, so won't elaborate. If you're looking for a deeper explanation as to why it should be avoided, then just ask.

For beginners, one set of an exercise is typically enough. As one passes this stage, however, more volume is necessary which means more sets per muscle per workout.