Intro to Plyometrics
By:  Sheila Kealey   (2005/06/21)

After 20 minutes of easy relaxed running, we used the grassy hill for ski walking, ski striding, ski walking and striding pulling a tire, and then did some strength work. This was followed by an easy 20 minute cool down run. I’ll describe three of the plyometric exercises we included in our strength work.

CLAP PUSHUPS:
This is a great upper body power exercise. Start in a regular pushup position with hands shoulder width apart; lower yourself keeping your body straight like a plank; EXPLODE off of the ground high enough to clap your hands, and then place your hands back into regular pushup position. As with regular pushups, keep good technique with a deep enough descent. We did these thee sets: (1) 20 pushups, (2) 15 pushups, (3) 10 pushups.

DOUBLE FOOTED JUMPS UPHILL
Legs together, hop continuously up a hill, keeping contact with the ground to a minimum. For this first outing, we jumped uphill for about 50 meters one time.

ONE FOOTED HOPS UPHILL:
Hop uphill on one leg, keeping contact with the ground to a minimum. We did three sets. Each set included about 40 hops as follows:10 left leg, 10 right leg, 10 left leg, 10 right leg.

Cool Down: 20 minutes of easy relaxed running.

An exercise is called “plyometric� when an eccentric muscle contraction is quickly followed by a concentric muscle contraction. This forces the muscle to contract rapidly from its weakest point - a full stretch position.

Plyometrics are done to develop explosive power. Some research suggests that performed properly and progressively, plyometrics may also help prevent injury by improving balance and stability. For cross country skiers, it should help develop the power that you need for the quick and snappy movements required for proper ski technique.

Here are a few things to note:
- Your muscles may be sore after your first plyometric sessions
- To get the best training effect, try to keep contact with the ground to a minimum
- Plyometrics can place a big strain on unconditioned muscles, joints and bones, so make sure you have a good base of strength training before beginning plyometrics, and start out gradually (fewer exercises, fewer reps).
- Grass is a good surface for plyometric exercises (don’t perform on a hard surface like concrete).
- Look for quality. The emphasis on speed and power rather than endurance, so don’t perform too many repetitions in any one session.

You can read more about plyometrics for xc-skiing here:
Foundations of Plyometrics.