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- Alex Hutchinson (@sweatscience)
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I ran a trail race last weekend that involved a waist-high creek crossing through pretty cold water. Climbing the long uphill after the creek, my legs were suddenly dead — I felt like I could barely get my feet a few inches off the ground. So I sympathize with the volunteers in this study, published online ahead of print in the Journal of Strength and Conditioning Research by researchers at the University of Connecticut.
The researchers used vertical jump to measure leg power in a group of NCAA D1 athletes, with three main purposes: (1) to see how much power would increase after a dynamic warm-up, (2) to see how much power would decrease if the subjects were pre-cooled by standing waist-high in 12 C water, and (3) to see if the dynamic warm-up could off-set the negative effects of cooling — something that would be of interest to athletes who compete in cold temperatures.
Everything was pretty much as expected. The dynamic warm-up increased jump power by 5%, and the cold water decreased jump power by 21%. When the subjects did a dynamic warm-up after cold-water immersion, they regained 70% of the lost power — not perfect, but still good to know.
Leaving aside all this cold-water stuff, the main reason I’m posting this is highlight the ever-stronger consensus that dynamic warm-up is the way to go. As the researchers note in their introduction:
Traditionally, static stretching exercises have been used by many coaches to prepare athletes for sporting activity. However, studies have shown that static and proprioceptive neuromuscular facilitation (PNF) stretching may negatively impact jump performance and power output. Dynamic warm-up exercises now appear to be preferred after many studies have compared the 2 modes and demonstrated dynamic exercises to be much more effective.
So what does that mean in practical terms? Well, here’s the dynamic routine the researchers used:
Continuous warm-up 1 (20 yds)
1. Arm circles forward X 1: walking forward on the toes while circling the arms forward with the arms parallel to the ground
2. Backward heel walk w/arm circles backward X 1: walking backward on the heels while circling the arms backward with arms parallel to the ground
3. High knee walk: walking forward and pulling the knee up to the chest with both arms, alternates as you walk
4. High knee skip: skipping forward and bringing the knee up so that the quadricep is parallel to the ground
5. High knee run: running while focusing on bringing the knees up so that the quadricep is parallel to the ground
6. Butt kicks: running while bringing the heel to the glutes
7. Tin soldiers: walking forward and kicking a single leg up in front while keeping the knee locked in extension (alternates)
8. One leg SLDL walk forward X 1: walking forward with straight legs, lean forward on 1 leg and reach for the foot with the opposite hand
9. 1 Leg SLDL Walk Backward X 1: walking backward with straight legs, lean forward on 1 leg and reach for the foot with the opposite hand
10. Backward skip: moving backward and skipping at the same time
11. Backward run: running backward and extending the rear foot behind you
12. Back peddle: moving backward while shuffling the feet and keeping them low to the ground
13. Overhead lunge walk: hands on the head while doing walking lunges forward
14. Inchworm: starting in the push-up position, walk the feet into the hands; then walk the hands out to the push-up position