Wow - lots of great questions this week. I'll go through these in order.

tora - There are several studies that have show that 5k runners who do plyos run faster, even though their VO2 and lactate do not improve, which means that Running Economy (RE) has gone up without any of the fitness gains that we normally associate with distance running.

I'll preface my comments by saying that this is where you need a coach - this type of workout only works well in the context of a well though out annual plan and only fits in certain mesocycle. That said, I'd do this following your "hard days" - especailly your VO2 max days (i.e. repeat 1,000's or 1,600s) and any thing at 5k or 10k race pace. If you do these after a long run then your nervous system might not know what to do; same with doing this after tempo runs, yet if you look at the Resources link above and watch the Shalane workout you'll see her doing a circuit following a tempo run. And to be honest, this is where having both DVDs helps - you wouldn't implement this until 6 months of General Strength (GS) and preventive work. Read below for how this leads to "real" Plyos.

Brain - I'm at a lose as I'm obviously not a Doc, yet my guess is that you would not want her to do this...lots of work for the foot, planter fascia, ankle and small leg muscles (i.e. perinials) in this workout.

PeytonH - Great question and the answer is NO. Do you normal plyos on the track or other harder surface (some Plyos are good to do on the new sport turf surfaces - bounding for instance). Think of this work as the work you'd do for 3-4 weeks then do "real" plyos. Remember, you have to have a good base of general strength before you try to implement power.

Lemon_in_the_X - No MedBall in this video, but yes, that's a great way to spend $30 to make yourself a better athlete and a better runner...but get one that bounces and don't get one that is too heavy for you. 4k or 8 lbs is good for most males.

rteter - The best question of the day and the question that I had filming this and still have. I've emailed Mike and I'll get back to you. However, I can say this - if you do this workout your legs will be tiered form all of the work...this workout is more about metabolism then it is about power. Compare this to say 3x3 36" hurdle hops for collegiate male 800m with 30 sec walk/stand rest; this is not hard at all metabolically but is a fairly serious nervous system stimulus. So, my guess as to Mike's answer is that the concentric phases are longer here, making your more fatigued then you would be in routine with a higher neural demand (i.e. power activities) which would have the quick coupling of concentric and eccentric.

...and maybe that's what Mike really means - the coupling is slow all of these, compared to the Hurdle Hop example.

Thanks to everyone who wrote in. Become a fan then email me your mailing address and I'll get a DVD to you.

When I was watching this video i noticed that the coach kept on saying this is more concentric and safe, and provides good "work". What actually makes this more concentric than doing it on the land? Is the sand working the core and stabilizer muscles more, or does it provide a type of resistance when you are pushing off. My question is how does doing the workouts on the sand actually provide more of a benefit then doing it on land.

I have an athlete with necrosis of one of her toes, which is essentially death of bone through inadequate blood supply. I wonder if this will help with her rehab?

Thanks!-Brian Manley

What would your recomendations be for implementation of these exercises in the training of a 5k/10k runner? What type of training sessions would these exercises follow for a 5k/10k runner?

Great routine for you to implement this time of year as it's a safe precursor to "real plyometrics" later in the year.

I'm going to leave it at that for now as there is no doubt that many of you will have questions after watching this. We'll give DVDs away to the first 4 QUESTIONS (not comments such as "My brother went to Chile and all he brought me was a jar of sand from the Atacama desert") and I'll answer those later today.

Also, congratulations to all of the athletes who set big PRs this weekend - some great performances out there.

Love the exercises you post. The myrtl routine is great. Wish I had a sand pit at home to try this new one out in, or that it wasn't 30° outside.

Hey Coach Jay,

Great concept of strenthening using sand as resistance! Would it be safe to do plyometric/form exercises and drills in the sand, as well? (I have the first DVD, by the way)