A few of my lifters (myself included) have spent most of the summer doing GPP work. If you don't know what GPP is, it stands for General Physical Preparedness. It's essentially the building of general capacities that increase our ability to do specific tasks.
One of the methods that have been included in these GPP phases is the use of short duration sprints, with full recovery between sets. By short duration, this often looks like 5-10 meters, repeated for 2-3 reps for 3-6 sets (built up over time). These were often done after skipping variations or pose running drills to help aid in form and positioning for sprinting. This was key, because for those going through the GPP phases a large part of our training is within the sagittal plane of motion and really only is vertical in nature. Needless to say, most of us do not look super graceful when we sprint, but we sprint because it's good for us.
Why Sprint though when the goal is to lift heavy weights?
When we look at rate of force development, and really the rapid muscle contractions involved in high velocity of movements, we have to understand the velocities that most weight room movements occur at. This is crucial for understanding why sprinting is necessary in a GPP phase.
Most bodybuilding or hypertrophy movements occur at less than 1.5meters/second (m/s). Most maximal strength movements such as squats, deadlifts, and presses also occur below 1.0m/s. Olympic Lifts like the Snatch, Clean, and Jerk are often hailed then as the "athletic lifts" because they occur at higher velocities between 1.5-3.0m/s. They're fast and powerful, and so they get included in training programs because of "how fast" they happen. This is not entirely untrue, but if we want to develop the true ability to move fast, we have to take a look at sprinting.
Even at rudimentary levels, a max effort sprint is going to move somewhere above 5.0m/s. That's right, it's almost double that of an Olympic Lift. At the higher end, most younger adults can usually reach somewhere in the 7.0-9.0m/s range. Elite level sprinters will then get in the 10.0+m/s ranges (think Usain Bolt).
When we want to build a General Capacity, we then have to look at getting muscles to contract fast. To create a motion that is fast, we need to contract muscle fast. Based on velocities, what is faster than a sprint? No much. At least, not much that doesn't require an inherent amount of skill. And while optimizing a sprint to reach above that 9.0m/s marker does indeed require skill, it doesn't require tons to reach above the 5.0m/s mark. So when we are building GPP for lifters, we want to spend time in those faster velocities ranges. This helps develop the capacity for speed, but also exposes muscles and tendons to varying contractile speeds that will benefit the body for its sport. When muscle and tendon are exposed to different levels of force and velocity, they build injury resilience (we can't totally prevent injuries) and allow lifters to be able to handle some of the faster or ballistic contractions that may occur within the lifts.
To fully build GPP then, we need to take some time to sprint. We need to take time to work at higher ranges of velocity that lifting can't reach. This helps build the body to moving even faster, and preventing it from breaking down when some of the other ranges of velocity are frequently visited. Especially for weightlifters who may experience the crashing of a clean or snatch and having to withstand the pressure of those movements, sprinting becomes a must in the GPP phases.