Naval Special Warfare (NSW) candidates have asked whether it is necessary or beneficial to include ruck marching when preparing for Basic Underwater Demolition/SEAL (BUD/S) or Alpha Phase. The bottom-line-up-front answer is that it is probably not critical for success, and if misused will do more harm than good; but used properly may fit into a well-rounded training program.
The term, “Ruck marching” refers to walking with extra weight in the form of a backpack or rucksack. Never run with a rucksack; the stress will only increase risk of injury. Walk at a moderate to brisk pace depending on factors such as distance, weight carried, fitness, experience with rucking, and terrain. Ruck marches are generally performed in BUD/S a couple of times during each Phase but may be left out if there is no room in the schedule. During Alpha Phase there's a ruck march on the schedule as well. Ruck marching isn't a testable evolution and there are no specific standards for pass/fail. A typical ruck march in BUD/S or Alpha Phase would be to cover three miles carrying 35 pounds in the O-Course/Demo Pit area (a combination of hard pack and soft sand). The pace would be around 14-13 minutes per mile (4.3 - 4.6mph). So, you may wonder if any specific training is required to perform this task, or whether rucking as a physical training activity is beneficial regarding overall or general fitness.
Rucking requires a combination of strength and endurance, so you can effectively prepare for rucking relying mostly on sound lifting and running programs. Looking at research on rucking (the U.S. Army has put out a lot of material), running ability is the strongest predictor of ruck march performance. The relevance to NSW is confirmed by data from SEAL Qualification Training (SQT) students as well as officer candidates in the SEAL Officer Assessment and Selection program (SOAS). When results of fitness assessments (including 3 mile run, 1K swim, 300yd shuttle, as well as bench press, dead lift, and weighted pull-ups) were compared to performance of timed rucks (40lbs/3 miles/uphill; 60lbs/9 miles/flat), running (without weight) was by far the best predictor of ruck times. The swim and shuttle run also correlated well. Strength values had lower and generally negative correlations (students who lifted the most weight tended to be slower during ruck marches). Bearing in mind that endurance (run and swim times) is the most important factor regarding the probability of completing Hell Week or the Tour, while pure strength is less relevant, the basic training paradigm for preparing for BUD/S or Alpha Phase in general applies specifically to preparing for the occasional ruck run in the training pipeline.
In the blog post called, BUD/S Is Not a Conditioning Program, I describe the common mistake of trying to recreate BUD/S before coming to BUD/S, so please review that article. When using rucking as general conditioning for BUD/S or Alpha Phase, the idea is to combine strength and endurance demands to create a potent training stimulus that mimics the demands of evolutions during selection. The concern is the combined strength and endurance overload may be more than you can adapt to and the resulting stress may cause injury or amplify possible injury factors. Rucking is stressful and it is important to limit exposure. Use it sparingly, start slow, add weight and distance gradually.
If you ruck, use it as cross-training to supplement your regular run/swim/lift workouts, as you would a bike ride or session on a Stairmaster. It may be better to use a weight vest rather than ruck sack or backpack (unless you know how to properly load and wear the ruck). Boots aren’t recommended for regular running, but provide good support for rucking (learn about proper foot care and the breaking-in process). The proper frequency for ruck marches is no more often than every 10-14 days. A reasonable starting point might be to march 1.5 miles carrying 10lbs. (If that sounds too easy, remember that training is a process that works best when you begin modestly and build gradually – focus on the end state, not the starting point). The next time you ruck, add 5lbs or half a mile (not both). At that rate, after 22 weeks you would be rucking with 35lbs for 5 miles. At that point, without further increasing weight or distance, you could focus on faster paces (without running) or more challenging terrain (hills, soft sand).
Naval Special Warfare Assessment Command