Safety & Health

Benefits of an Interval Run Program

Issue 3 and Volume 6.

The purpose of any firefighter’s cardiovascular program is to help them work more efficiently under the stresses encountered every day on the job, be it on the fire or rescue ground. The fireground is generally the most hazardous, so let’s look at it: A firefighter will experience an initial adrenaline rush as they hear the call come out, put on PPE and listen to radio reports of what’s happening on scene or view a column of smoke as they approach the incident.

Upon arrival and jumping to action, the body is once again taxed as the firefighter dons SCBA, grabs tools, deploys hoselines and forces entry—and that’s all before they get into the fire building and start working.

As we all know, even after the fire is out, there’s much work to be done during salvage and overhaul. We also have to load hose and other equipment to get everything back in service and that takes a lot of hard work. I often tell my students that a firefighter’s job is never finished, because there’s always one more thing to that needs to be done, and it’s true.

I also ask my students, what do you do when you feel like you have nothing left to give physically, and yet there are tasks you must still complete? I think most firefighters have felt this way a few times in their career. You’ve just finished a tough assignment where your body was taxed beyond its normal limits and there’s one more thing to do, but you know it won’t get done by itself, so it’s up to you and your crew to do it. These are the times that will make you happy that you took fitness training seriously. These are the times that will help you solidify yourself as a strong team member. But we can’t achieve this type of success without engaging in a solid cardiovascular program.

I like to use three cardiovascular training strategies: the long, slow, distance run, interval training and run-work-run (RWR). For this article, I’ll concentrate mostly on the interval training strategy because it’s an expandable program that any firefighter can use, whether they’re just beginning fitness training or they’re more advanced. Intervals also mimic firefighting activity patterns more than long, slow, distance runs, and they can help you prepare for a RWR program.

Program Objectives
When considering cardiovascular programs for firefighters, we must keep in mind that any useful program should improve two physiological processes. First, we want to it raise our VO2 max, which, simply put, is the greatest amount of oxygen our bodies can use during maximum aerobic effort. Firefighters who can work longer before they reach their VO2 max will be able to accomplish more than those with a lower VO2 max.

Just as important as the VO2 max is the maximal lactate steady state (MLSS). This refers to the point where the body’s lactate production is equal to lactate clearance. Lactate is basically lactic acid that’s been converted into salt so the body can use it as energy; however, when lactate is not cleared and instead builds up in the body, we develop a build-up of lactic acid and hydrogen ions that are associated with the burning sensation we feel in our muscles when under heavy physical stress. It has been shown that trained individuals will clear lactate faster than those who aren’t trained and will therefore feel less pain when undergoing physical exertion. The bottom line: We want to build a cardiovascular training program that enables us to work longer and harder with less physical pain when it really counts.

How It Works
I like to use a distance-style interval program because it’s easy to follow and record, and there’s no special equipment needed, such as a heart monitor or even a stopwatch.

To perform, go to your local track and begin by walking/jogging a warm-up lap. Then sprint the 100-yard straights of the track and jog the curves, completing 1 mile, or four laps. (I am assuming your local track is a typical 400-meter track that’s typically found around a football field. On rare occasions, you may find a track that’s larger or smaller than 400 meters.) Upon completion of the first mile, sprint half a lap and jog the other half until you’ve completed another mile. After completing the second mile, sprint a full lap, then walk/jog a lap and then repeat the full-lap sprint followed by the walk/jog lap.

This particular program covers a total of 3.25 miles (including the warm-up lap), but it’s designed so that the participant can customize it based on their fitness level. If you’re just beginning, you may reduce the distance and the amount of sprints. Likewise, if you’re looking for extra work, you can increase the distance, incorporating 600- and even 800-yard interval sprints with slower jogs/walks in between. You are your own “fitness lab rat,” so start out by doing what works for you and what you’re comfortable with and then start pushing yourself to the next level.

Tip: Keep records of your total distance covered as well as the sprint portions you complete every time you go to the track. You may also want to record your overall time as you increase your distance. Record keeping is a good way to set and maintain goals for yourself as you progress through any exercise regime. There are other programs that also keep track of your heart rate, but if you’re like me, you want to keep it simple.

If you don’t have a track that’s easily accessible and you do your intervals at a park, you may want to bring along some cones to help visualize your landmarks.

RWR Program
When you get acclimated to the intervals and begin looking for even more demanding physical challenges, you can try the RWR program. The RWR blends interval training with exercises such as sit-ups, squats and push-ups. For example, during an RWR workout, you would do a set of 10 sit-ups, 10 squats and 10 push-ups before each sprint of your interval program. During inclement weather, or just for a change of pace, you may use  any type of cardiovascular training equipment, such as stair masters, treadmills or stationary bikes, or throw in a jump rope to mix it up. For the ultimate RWR challenge, mix in some hose pulls as well, and you’ll take your workout to a whole new level.

One added benefit to any cardiovascular program: the extra calories you burn as the body catches up with the oxygen demand placed on it during exercise. This is also known as elevated post-exercise oxygen consumption (EPOC). It is thought that an individual’s metabolism remains higher for longer periods of time after high-intensity training.

Points to Remember
When building your cardiovascular fitness program, it’s important to keep adaptation in mind. Simply stated, adaptation involves changing up your workout on a regular basis so that your body must constantly build new neuromuscular pathways to build strength. In the case of cardiovascular training, constantly challenge your heart and lungs to meet the new stresses placed on them.

Some other ways to do this beyond what we’ve already discussed are to add inclines to your run, such as stadium steps or a local hill or mountain. If you live near the beach, run in the sand. Do sets of high knees, over-strides, or skips and hops. Basically whatever you can throw in to stress yourself will work. Find out what works best for you and then stick with it!

Baechlee, T, Earle, R, editors: Essentials of Strength Training and Conditioning. Human Kinetics: Champaign, Ill., 2000.
Ehrman, J, deJong, A, Sanderson, B, et al, editors: ACSM’s Resource Manual for Guidelines for Exercise Testing and Prescription, sixth edition. Lippincott, Williams and Wilkens: Baltimore, Md., 2010.