Back in May, I wrote a blog about whether we should go heavy or light in a Turkish Get-up. The answer is "yes." The same holds true of the kettlebell snatch.
When Kenneth Jay's book, Viking Warrior Conditioning, came out a few years ago many people in the RKC family just stopped snatching heavy. Now, I am a fan of the Viking Warrior Conditioning protocol of 15:15 secs work: rest ratios of relatively light snatching for 20-40 minutes. I did this program 2-3 times a week for about a month and was very lean as a result. I'm all for VWC if done with proper form (there were many instances of short changed snatches that didn't finish at the top in an effort to get more in quicker but that is a different point) and if paired with heavy snatch days.
The heavy snatch is the yin to the light snatch yang - a phrase I also used to describe the relationship between the light and heavy get up. They both have benefits and they both are important. While you can get your heart rate up and get lean with both (If you want the science behind VWC, grab the book. Kenneth explains it much better than I could) the heavy snatch will give you more power production. You won't get as many reps in, but you won't need to. Efficiency is a good thing!
How does this fit into a training program? If you are designing a snatch intensive program, I would make one day a week more VWC style and do a whole bunch of light snatches (8 or 12kg for women, 16 or 20kg for men) for a long period of time (20-40 minutes with a 15:15 secs work:rest ratio) and then on another day, I would do 10 minutes of heavy snatching with the same work:rest ratio, but with a heavier bell.
Do your snatch practice AFTER your grinds. This way you are not only safe, but you can go all out without worrying about saving energy for the slower strength exercises.
Should you snatch heavy? Absolutely. There is a place in your training for both light and heavy snatching and if one is left out, an important piece of a well rounded program is missing.