When most people think of training to improve endurance, they think of conditioning the cardiovascular system to improve transport of blood to the working muscles. Metabolic conditioning is the other side of the coin - conditioning the muscles to better use what’s being delivered to them by improving the efficiency of the different metabolic pathways.
I have been reading a bit around Drew Baye's blog. There is a lot of good stuff in there.
He has an interesting piece on Crossfit in which he gives a "high intensity" take on Crossfit. I don't necessarily agree with it all but there are some good points.
I also like his 3x3 conditioning circuits:
3×3 is a high intensity strength training routine consisting of three circuits or rounds of three compound (multi-joint) exercises performed non-stop to emphasize cardiovascular and metabolic conditioning. Each of the three exercises targets different muscle groups, usually starting with the hips and thighs, followed by upper body pushing and pulling movements, to work all of the major muscle groups and allow for little or no rest between exercises.
The following are just a few variations of the 3×3. Many more are possible depending on your capabilities and the available equipment.
- Barbell or trap bar deadlift
- Standing Press
- Bodyweight squats or alternating one-legged bodyweight squats (AKA pistols)
- Handstand, incline or diamond push-ups
- Chin-ups or front lever pull-ups
A higher number of repetitions is usually performed for the first circuit, with the repetitions dropping for the second and third circuits. A typical repetition scheme for a 3×3 routine is 20, 15 and 10 for the hip and thigh exercise, and 12, 10, and 8 for the upper body pushing and pulling exercises.
If you are performing 3×3 routines exclusively or frequently I recommend rotating exercises every workout or at least every other week, so that you can incorporate more variety of movement and more direct work for different muscle groups. You should alternate between upper body pushing and pulling movements in different planes and between pushing and pulling lower body movements.
I prefer pairing pushing and pulling movements in similar planes, such as presses and chin ups, or dips and rows. Due to the greater overlap in muscle involvement between horizontal and low rowing movements and deadlifts, when deadlifting I recommend vertical pulling movements.