NAVY SEAL TRAINING BLOG

By Mike Caviston, Director of Fitness, Naval Special Warfare Center

In recent Blogs I’ve been clarifying some issues related to LSD workouts, so I thought this would be a good time to emphasize proper execution of interval (INT) workouts as well. The goal of the INT format in the NSW PTG is to build up to performing 10 x ¼ mile at the fastest pace that can be sustained for the entire workout. That is very demanding both physically and mentally, but a very effective means of improving your performance on the 1.5-mile run portion of the PST. However, many candidates make fundamental mistakes when executing the INT format regarding the number of intervals they start with; how fast they try to go when just beginning training; how consistently they pace the workout; how well they recover between intervals; and how quickly they try to improve from week to week.

I can never repeat enough the importance of taking a long-term approach, and to encourage candidates to focus on achieving consistent gradual progress over several months, rather than trying to achieve instant gratification and stupendous results right now (because this rapid initial increase is almost certain to precede an early plateau followed by a decline in performance). Week 1 of the PTG’s 26-week program begins with four ¼-mile intervals, at a pace only slightly faster than your recorded pace for a 1.5-mile run. Even if you are an experienced runner and are able to begin following the PTG program running more LSD miles than are listed for Week 1, I still encourage you to begin the INT workouts at Week 1 and perform only four repetitions. You should initially shoot for a pace during your ¼-mile repeats that is about 4 seconds quicker than your ¼-mile pace during your 1.5-mile run and no faster. For example, if your 1.5-mile time is 10:00, your pace for your first INT session should be about 1:36. A session of four repeats at this pace is probably not going to feel too tough, but that shouldn’t concern you at this point. You just want to set yourself up for long-term improvement; eventually you’ll achieve some real speed. I’ve talked with candidates who have become burned out or suffered from complaints such as lower leg pain, and this almost always correlates with doing too many intervals at too fast a pace too early in training. Some coaches would recommend not using intervals at all in the early weeks of training, but I feel it is safe and will lead to better long term performance as long as the prescribed guidelines are followed.

Since the INT sessions for the first few weeks will be relatively short, use the time to establish a thorough and effective warm-up routine. Add another interval to your workout every couple weeks according to the schedule in the PTG. Don’t worry about increasing your speed until you build up to the full ten intervals. Work on consistency and pacing, trying to run each interval with no more than one or two seconds difference between your slowest and fastest. After you build up to ten intervals, doing them all consistently near your goal pace, you can start working on doing them a little faster every week. Still, don’t be in too much of a hurry to go too fast too soon, and keep it steady. It defeats the purpose of the workout if you do the first interval in 65 seconds but shoot your wad, get slower and slower with each repeat and finish with a 2-minute interval. Between intervals, take enough time to adequately recover (about 2 to 2.5 times as long as it took to run the previous interval). Stay on your feet, keep moving, do a little jogging for active recovery, and stretch as needed.

Keep a record of all your sessions. After developing a fairly consistent pace with a steady rhythm, every week try to knock another second or two off your last couple intervals, finishing each workout strong. For example, if the previous week you finished ten intervals at an average pace of 1:30, continue to hold a 1:30 pace for the first several intervals of your next workout but bring it down to the 1:29-1:28 range for intervals 8-9, and then open it up for the last rep. The week after that, start the INT workout at roughly the same pace as your average from the last session and repeat the process all over again. If you are patient, you will eventually see a significant reduction in your times. Taking even one second off your average pace each week for fourteen weeks adds up to a pretty big improvement. If you train smart, you will develop enough experience to be able to push yourself hard from the start but still have enough stamina to finish the whole workout. As training becomes more physically and mentally demanding and it becomes harder to get faster from week to week, you will improve and refine your tactics for dealing with the discomfort and the urge to quit. This application of determination, strategy and goal-setting to achieve a long-term objective using short- and medium-term targets is consistent with the type of mental toughness required to get through BUD/S.

For variety, rather than always doing 10 x ¼-mile, you can occasionally do alternate formats of the INT session using 200m or 600m intervals as well as the standard 400m (a quarter mile is equal to 400m). For example, do 6 x 600m to work on sustaining your 400m speed a little longer. Another possible format might be 3 x 600m, followed by 3 x 400m, followed by 3 x 200m. Use any combination that adds up to no more than 4000m (approximately 2.5 miles). It probably won’t be possible to hold your ¼-mile speed for 600m repeats, so expect to go a little slower, and obviously you would need more time to recover after 600m compared to 400m. On the other hand, for 200m you would be able to go even faster than ¼-mile speed and take a little less recovery. These occasional variations would let you work on slightly different parts of the speed continuum as well as shake things up mentally. Make sure to do your INT sessions on a firm even surface that is safe (you don’t want to sprain an ankle or twist a knee) and fast (after all, it’s a speed workout). Trail running or the beach is good for some LSD work but not optimal for INT. A good outdoor track is ideal, but a bike path or similar surface can work (watch out for traffic). Be careful if you use an indoor track, because if it isn’t banked properly the tight turns will be hard on your legs. If you are temporarily unable to run for an INT workout (minor injury, bad weather, etc.) follow my general training recommendation (also applies to LSD and CHI) and use an alternate activity to mimic the intensity of the regular workout. Use a treadmill with a slight incline, a stationary bike, or a rowing machine to work as hard as you can for the same time periods it would take you to run your ¼-mile repeats and spend the usual amount of time recovering.

Finally, remember to put INT sessions in the proper context of total training. As I’ve discussed previously (“Is Long Slow Distance Wrong?”), INT training is a fantastic tool to improve fitness, but it must be balanced with lower intensity sessions. The “all-out, all the time” approach is counterproductive. That’s just a matter of human physiology, and we can’t change it, no matter how tough or hardcore we think we are. For anyone interested in a (fairly technical) summary of research that has investigated the balance of training intensity and duration for high-performance endurance athletes, please see the following:

http://sportsci.org/2009/ss.htm

From the article’s conclusions:
“Currently, there is great interest in high-intensity, short-duration interval training programs. However, careful evaluation of both available research and the training methods of successful endurance athletes suggests that we should be cautious not to over-prescribe high-intensity interval training or exhort the advantages of intensity over duration.”
“HIT should be a part of the training program of all exercisers and endurance athletes. However, about two training sessions per week using this modality seems to be sufficient for achieving performance gains without inducing excessive stress.”
“The effects of HIT on physiology and performance are fairly rapid, but rapid plateau effects are seen as well. To avoid premature stagnation and ensure long-term development, training volume should increase systematically as well.”

By Mike Caviston, Director of Fitness, Naval Special Warfare Center

In my previous Blog post I confronted the perception that high mileage may be counterproductive to performance and encouraged candidates to incorporate LSD training into preparation for BUD/S. On the other hand, others have asked if there is enough mileage in the PTG to adequately prepare a candidate for BUD/S. Some candidates have looked at the numbers and noted that the NSW Physical Training Guide 26-week program seems to build to a weekly total of approximately 20 miles, which falls short of the 30-40 miles per week that pops up in various sources as a recommendation for preparing for BUD/S. I’ve addressed this apparent contradiction a few times on the Training Forum, but I want to make a definitive statement here.

The PTG was designed to accommodate untrained but healthy candidates, and a basic premise is to begin training with a moderate workload and gradually and progressively increase the training volume and intensity over several weeks. This is necessary to avoid the common beginner training mistake of attempting too much mileage too soon, often leading to burnout and injury. So the mileage prescribed in the early weeks of the 26-week program is pretty light by the standards of experienced runners or athletes that have been active in a number of sports that include running. But athletes with a solid conditioning base may enter the program at a higher mileage as long as it is consistent with their current fitness and training habits. Please note, this refers to candidates who have actually been following a progressive running program and have actually completed the necessary base mileage; candidates should never enter the program based on what they think, wish, hope, or assume they should be doing.

After several weeks of training with the three weekly running workouts prescribed by the PTG, you might decide to add a second weekly LSD session. I would recommend an unbalanced format that includes a longer session as well as a shorter session (about 50-75% of the distance of the longer session). The pace would be approximately the same for each session; don’t do the shorter run at a faster pace and turn it into a CHI workout. A general target would be to build up to a longer run of 8-10 miles with a shorter run of 5-6 miles. (Note: build up means a gradual increase over time. For example, during Week 13 you might do a long run of 5-6 miles and a short run of 2-3 miles, adding ¼-½ mile to each session each week.) Some experienced, competitive runners may have the background and ability to eventually go even longer than 10 miles, maybe as far as 15 miles or more in a single session. If you have the desire and ability and necessary baseline preconditioning for that kind of mileage, I wouldn’t discourage you. But I have no basis for claiming that being able to run comfortably for more than 10 miles will be a significant advantage, so I don’t want anyone to feel as though they absolutely must exceed that distance before starting BUD/S.

Let’s do a summary of the total weekly mileage you might achieve while doing one INT, one CHI, and two LSD workouts. Let’s not forget to account for the warm-up and cool-down portions of the workouts. INT and CHI workouts require prolonged warm-ups to increase the effectiveness of training and decrease the risk of injury. Post-workout cool-downs (and active recovery between intervals) facilitate recovery. Even LSD workouts should begin with a brief warm-up. See the Physical Training Guide for details. Don’t count these additional miles as part of the specific workouts, but they do affect your overall fitness and should be counted towards your total weekly mileage. I’ll use some general numbers for illustration, but your actual miles might vary to some extent.
INT session: warm-up = 2.5 miles; 10 x ¼-mile = 2.5 miles; active recovery between intervals = 1.0 mile; cool-down = 1.5 miles; total = 7.5 miles.
CHI session: w/u = 2.5 miles; 2 x 20 min = 6 miles; active recovery between intervals = 0.5 mile; c/d = 1.5 miles; total = 11.5 miles.
1st LSD session: w/u = 1.5 miles; LSD run = 10 miles; total = 11.5 miles.
2nd LSD session: w/u = 1.5 miles; LSD run = 6 miles; total = 7.5 miles.
Grand total, all four sessions: 38 miles.
This comes pretty close to 40 miles per week, and the intensity of the INT and CHI running equates to greater volume than the same number of LSD miles, so we’re looking at the equivalent of 40+ miles per week following the format prescribed by the Physical Training Guide. For candidates who build up to this running volume gradually and progressively, and have also maximized their swimming mileage, and are looking to develop even greater cardiovascular endurance, I encourage the introduction of non-weight-bearing activities such as cycling or rowing.

Remember to be sure to incorporate general as well as specific injury-prevention strength training as well as flexibility exercises into your running routine. Review the recommendations in the PTG; see my previous blog post “Running at BUD/S”, and check out the documents and videos provided by LCDR Cowan (BUD/S Physical Therapist) on the SEALSWCC.com Medical and Videos pages.

By Mike Caviston, Director of Fitness, Naval Special Warfare Center

Endurance is one of the physical attributes required to succeed at BUD/S. The NSW Physical Training Guide features workouts to develop running and swimming endurance as a means of maximizing performance on the PST and preparing candidates for the rigors of the various training evolutions performed at BUD/S. The program features workouts using short interval (INT) and long interval (CHI) formats as well as sessions of prolonged, continuous activity (LSD). The interval formats are essential to the program and a critical training tool to maximize performance. I am a huge advocate of interval training. But my firm recommendation to candidates following the 26-Week program in the NSW PTG is to keep the number of interval sessions limited to one INT and one CHI session per activity (running and swimming), and gradually increase the length and number of LSD sessions as fitness develops. Many candidates attempting to follow the PTG have heard from one source or another that LSD training is either not useful because it is not demanding enough, or actually detrimental to performance because it diminishes the effectiveness of strength and speed training. I want to address those issues here.

The use of the term “LSD” may be confusing or misleading for some. While it does stand for Long Slow Distance, it only means “slow” relative to the paces you use for INT and CHI workouts. The pace has to be slow enough to allow you to complete the required distance. But “relatively easy and relaxed” doesn’t mean “no effort” and doesn’t mean that you won’t sweat. A certain amount of intensity is required before adaptations will occur. Rather than being “slow” or “easy”, LSD training can actually be quite challenging, and I prefer to think of LSD as Long Sustained Distance.

A simple and accurate way to determine the appropriate intensity for LSD is to use the Talk Test. Pay attention to your breathing, and choose a pace that causes you to breathe somewhat hard but not too hard. You should be able to talk in short/choppy sentences, not gasping uncontrollably but not making longwinded speeches either. (Some people prefer to monitor their heart rate during training, which requires laboratory stress testing for complete accuracy, but I believe monitoring your breathing is simpler and just as effective for gauging the right pace to enhance endurance without overextending yourself.) As your fitness increases, you are able to work at a greater percentage of your max for extended periods without gasping for air, so the Talk Test is self-adjusting relative to your ability.

Endurance training may have some slight negative impact on strength and speed. As the muscles receive multiple signals from various training stimuli (LSD workouts, lifting heavy weights, sprints) some of the signals will conflict with each other. An Olympic weight lifter or hurdler trying to maximize muscle mass or contraction velocity would want to significantly limit LSD training. But elite athletes operate in an arena where specialization is required, and the difference between winning and losing is just a tiny fraction of a percent of actual performance. For BUD/S students and potential SEAL Operators, it is essential to be well-rounded and capable across the entire physiological spectrum. This means being able to move effectively in short bursts and lift heavy weights, but also able to cover long distances over rough terrain and still have a steady enough pulse to shoot straight when you reach the target. It also means having the ability to recover quickly after a max effort to be able to go again with little down time. Training for such diverse situations requires a little give-and-take, and optimal adaptations won’t occur across the board. But realistically, adding a couple tenths of a second to your 40-yard dash while knocking five minutes off your 10K run is a good trade any day.

One common argument against LSD training is that high-intensity interval training is sufficient to substantially increase aerobic capacity (VO2max). This is true and is one of the reasons I include INT training in a general fitness program, but a large aerobic capacity is not enough to guarantee ample endurance. The Three Factors of Endurance are aerobic capacity (VO2max), lactate threshold, and economy (the rate of oxygen consumption required to hold a given pace; related to efficiency). [Here is a link to a review in the Journal of Physiology for anyone who wants a little more technical information: http://jp.physoc.org/content/586/1/35.full.pdf+html]. Economy is affected by body type (body mass, height, limb length, etc.) as well as technique. You can’t alter your genetics, but both INT and LSD training can lead to better technique and improved economy (and therefore greater endurance). A large aerobic capacity requires a big strong heart that can pump many liters of oxygen-carrying blood per minute, and the intensity of INT training will stimulate the pumping chambers of the heart to become larger and more powerful, resulting in increased stroke volume and cardiac output. A high lactate threshold allows you to work at a greater percentage of your max for prolonged periods, and to recover more rapidly between shorter, high-intensity bursts. I like to include both INT and LSD formats in training because they complement each other. The ability to recover more quickly/completely between intervals as a result of LSD training allows you to work harder when running ¼-mile repeats, for example. The prolonged, continuous nature of LSD training stimulates increased muscle capillary and mitochondria density, resulting in an increased ability to optimize blood flow, remove excess heat and metabolic waste products, and utilize fatty acids for fuel – all leading to increased endurance and more rapid recovery.

The useful adaptations stimulated by proper LSD training are not adequately addressed solely by INT training. Limiting your fitness program to short, high-intensity workouts without corresponding LSD training is like building an automobile with a high-performance, large horsepower engine but a tiny 5-gallon gas tank. You may go fast but you won’t go far.