Manys runners loathe the idea of dropping mileage and replacing the "lost" miles with explosive strength training, but new research from Finland reveals that such a strategy can significantly improve maximal running speed and leg muscle power - workout any loss in maximal aerobic capacity. In the new investigation, experienced runners reduced weekly mileage by 20 percent and upgraded maximal running velocity by 3 percent. REPLACING MILES WITH EXPLOSIVE MOVES

What happens if you suddenly decided to chop 20 percent of your usual miles from your weekly log - and then replaced that lost mileage with explosive training which required a comparable amount of time? Many runners would suggest that such a move would deplete maximal aerobic capacity (VO2max), because of the lower overall volume of endurance training which would be conducted. Furthermore, many coaches and runners would say that the change would produce a drop in fitness and race performances, because of the necessarily abridged maximal aerobic capacity. Given such thinking, it is not at all surprising that so few runners carve away at their mileage and substitute explosive work for their endurance-type training.

However, there have been various hints in the scientific literature that such substitutions could produce surprising benefits. Some research, for example, has shown that "anaerobic work capacity" (the kind of thing which is fostered by explosive training) can have an important impact on endurance performance (1). In addition, Tim Noakes' now classic paper revealed that "neuromuscular characteristics" {basically, the ability of muscles to produce high amounts of force very quickly) could predict endurance-performance capability more successful than good-old VO2max (2). Producing force quickly is a key adaptation associates with explosive training. Thus, these inquires suggest that the traditional thinking about mileage and high-power work might be wrong.

Fortunately, the question of what really happens when endurance work is replaced by explosive training intrigued by Jussi Mikkola, Heikki Rusko, and their colleagues at the Research Institute for Olympic Sports in Jyvaskyla, Finland. Recently, Mikkola, Rusko, and their co-workers asked 13 well-trained young runners (nine males, four females) who were training about 8.8 hours per week to pare 1.7 hours from their weekly logs (leaving about 7.1 hours of endurance training) - and then to incorporate 1.7 hours of explosive training into their schedules each week for a period of eight weeks (thus maintaining the usual 8.8 total hours of effort). These runners were young (average age = 17.3 years) and fit (mean VO2max = 62.4 ml'kg-1 min-1). REPLACING MILES WITH EXPLOSIVE MOVES

The explosive training was carried out three times a week (which meant that each session lasted for about 34 minutes). The workouts consisted of high-speed sprint intervals ((5 to 10) X (30 to 150 meters)), jumping exercises with no additional resistance (alternate-leg jumps, and hurdle jumps), and "gym exercises" with fairly light resistance (half squats, knee extensions, knee flexions, calf raises, abdominal curls, and back extensions). For the gym exertions, two to three sets of six to 10 repetitions were utilized, and the underlying philosophy for all of the explosive movements was to use very high action velocities.

And, yes, this was a Heikki Rusko study, so there was a very nice control group - 12 individuals in all (nine men and three women) who were also young (17.3 years) and fit (VO2max = 61.8 ml'kg-1min-1). These controls pretty much stayed away from the explosive training during the eight-week period, instead focusing on 8.5 hours per week of endurnce training.

Muscle strength, jumping ability, and 30-meter running speed were measured in both the explosive and control groups at the beginning and end og the eight week period. And - since this was a Rusko study - all runners performed a maximal anaerobic running test, or MART (Rusko is one of the primary developers of the MART). A MART can be completed on a treadmill (3 & 4), but in this research the testing took place on an indoor track. Basically, a MART is a series of 150-meter runs, with 100-second recoveries between runs and a five meter flying start before each 150-meter effort. The velocities of the 150-meter runs are tightly controlled. In this research, the first was carried out at 39.4 meters per second (101.5 seconds per 400 meters) for females and 4.75 meters per second (84 seconds per 400 meters) for males. After that, the velocity was increased by .41 meters per second for each consecutive 150-meter effort. At the well equipped Rusko lab in Jyvaskyla, the runners were guided into running at the correct velocity by a "light rabbit" (a moving light which moved around the track at the required speed). In a MART, the last 150-meter run is completed at maximal effort, and ordinarily about nine to 10n 150-meter surges are completed per test. Fairly fast speeds are attained during the test. For example, a male runner who manages to perform 10 150-meter runs would complete the last effort at no less than 8.44 meters per second (47 seconds per 400 meters, if he could "hold on" that long).

Over the course of eight weeks, the explosive training paid major dividends. The maximal speed in the MART (the velocity attained for the last 150-meter sprint) increased by 3 percent in the explosively trained runners - but failed to budge at all in the regular, endurance-trained subjects. Furthermore, 30-meter speed (the top velocity achieved in a 30-meter sprint which was preceded by a 20-meter flying start) advanced by 1.1 percent for the explosive runners - but was stagnant for control individuals. REPLACING MILES WITH EXPLOSIVE MOVES

To learn more about how REPLACING MILES WITH EXPLOSIVE MOVES (the full article can be read by purchasing VOL. 23-3 of Running Research News) and many more running related topics, simply click-on the Back Issues link, and select the volume and issues number, from the drop-down menu. A subscription to RUNNING RESEARCH NEWS is another way to receive valuable information about running.

In theory, triathletes should have fewer overuse injuries, compared to other endurance athletes. After all, "cross training" is believed to minimize the risk of injury (and is even prescribed for injured athletes as a way to recovery), and triathletes cross train routinely. A triathlete whose main strength is running, for example, could be described as cross training for two-thirds of all workouts (if running, swimming, and cycling workouts occur with equal frequencies). Indeed, initial reports indicate that overuse injuries may be lower for triathletes; one study found an annual overuse- injury frequency of 41 percent in a group of triathletes, compared with the usual 50 to 65 percent injury rates found in "pure" runners ("An Epidemiological Investigation of Training and Injury Patterns in British Triathletes, "British Journal of Sports Medicine, Vol.28, pp. 191-196,). TRIATHLETES

However, other research has identified a 90 percent (!) injury rate in triathletes, well above the norm for endurance-sport participants ("Overuse Injuries in Ultraendurance Triathletes," American Journal of Sports Medicine, Vol. 17, pp. 514-518). Indeed, some sports-medicine experts argue that triathletes are more prone to injury, since each of the three triathlon sports tends to trigger a particular type of malady.

Swimming, for example, is known to induce shoulder injuries, which are seldom seen in running. Biking is associated with a higher risk of low-back problems, which are usually not a problem in endurance swimmers. In addition, triathletes often carry out more total workouts per week, compared with " straight" swimmers, runners, or cyclists. From these perspectives, triathlon competition might be considered a "high-risk" sport.

So the question remains: Do triathletes get injured more or less often, compared with "specialist" endurance athletes? In addition, which triathletes are at the highest risk for injury? Do psychological state, physical build, age, and gender play a role in determining risk? How about the number of years of triathlon experience, the time spent competing, training pace, and even stretching?

To answer these questions, researchers at Staffordshire University in Stoke-on-Trent recently examined the five-year training programs of 12 elite triathletes from British National Squad, 17 national-development-team memebrs, and 87 male club triathletes ("Injury and Training Characteristics of Male Elite, Development Squad, and Club Triathletes," International Journal of Sports Medicine, Vol. 19, pp. 8-42). An injury was defined as any musculoskeletal problem causing cessation of training for at least one day, a reduction in training mileage, the taking of pain medicine, or the seeking of mediacl aid. Overuse injuries were recorded separately from traumatic injuries, such as those resulting from bicycle accidents. TRIATHLETES

As it turned out, injury prevalence did not differ significantly between the ability groups; 75 percent of elite, 75 percent of developmental, and 56 percent of club athletes suffered an overuse injury during the five-year period ( the downturn in injury rate in the club athletes was not statistically significant); total time taken off from training as a result of injury was also not different between groups.

In addition, there was no significant difference between the three groups in the proportions of athletes sustaing injury in particular parts of the body; for example, club athletes were no more likely to sustain Achilles-tendon injuries, compared with developmental and elite triathletes. The knee, Achilles tendon, and lower back tended to be the most-injured body areas for the athletes overall. Injury occurrence was not linked to age, height, weight, or body-mass index.

                                            The Curse of Running

As you might expect, running injuries were responsible for most of the problems, accounting for from 58 to 64 percent of all injuries in the three groups; cycling was far back with 16 to 34 percent, and swimming produced very few difficulties. A key question then was: What factors increased the risk of running injury? The Staffordshire-University researchers were able to identify total weekly triathlon training distance (the sun of running, swimming, and biking mileage), weekly cycling distance (!), swimming distance per week, total number of workouts per week, cycling training pace, and number of weekly running workouts as key risk factors for running injury.

These findings might seem surprising at first. After all, why would an extra hour spent swimming or an extra 40K on the bike increase an athlete's risk of developing a running injury? The key, of course, is that while such efforts do not produce the kind of impact damage to muscles associated with running, they can - when carried out in large-enough volume - retard muscular recovery enough so that muscles respond less well to the stress of running and are thus more vulnerable to being injured as a result of run training. TRIATHLETES

Triathlon training is a true "balancing act;" workouts which ultimately improve cycling or swimming fitness can sometimes hurt running capacity or even increase the risk of sustaining a running injury by temporarily retarding muscular recovery. In such cases, it might be better to attempt to improve cycling or swimming fitness less avidly and thus maintain the ability to run strongly and without injury. When a triathlete plans a high-quality bike or swim workout, he/she needs to take into account not only the effect the session will have on bike/swim fitness but also the impact it will have on subsequent running efforts. If a killer bicycle exertion boosts cycling fitness a notch or two but prevents the completion og high-quality running workouts, what has actually been gained?

For many triathletes who want to improve overall performance - and who are training within limited time frames, the key may be to assess in which sport the greatest gain can be made, i.e., the sport in which the greatest improvement in overall race clocking can be attained. That sport will then be emphasized most heavily in training - and workouts in the other two activities which might hinder development in the "high-improvement" sport will be eschewed.

What about injury? Is the triathlon truly a high-risk sport? The 75-percent injury figures cited above seem high, but it's important to note that such a rate of overuse injury was observed over a five-year period; in comparsion, studies have found that 50 to 65 percent of endurance runners are injured during just one year of training. Thus, overuse-injury frequency often ranges from nine to 12 training sessions per week. Avoidance of a pattern of "hammering away" in a high impact sport such as running and an engagement with three different movement patterns (running, swimming, cycling) does indeed seem to be beneficial, from an injury-prevention standpoint. On the other hand, the three-movement plan probably does not give triathletes an advantage over pure swimmers and cyclists; since the latter do not include running in their training schemes, they are likely to have lower injury rates, compared with athletes.

Here is our final take-home point: Since triathlon injuries tend to revolve around the knee, lower back, and Achilles tendon, triathletes should spend extra time strengthening those parts of their bodies in functional ways, i.e., during movement patterns which mimic those occurring naturally in their sports. TRIATHLETES

To learn about Glucosamine and Chrondroitin Sulfate: Great Theraphy For Athletes' Joints?, Is The Use Of Variable Pace Better Than Keeping An Even Keel?, Or Rage Against The Machine: Re-Build Your Body Without Expense Exercise Equipment  (the full articles can be read by purchasing Vol. 17 Issue 8 of Running Research News) and many more running related topics, simply click-on the Back Issues link, and select the volume and issues number, from the drop-down menu, or type in another topic of interest. A subscription to Running Research News is another way to receive valuable information about running. BUY NOW.

Don't get too bummed out if you've had a running-related injury during the past 12 months. After all, you're in the majority. Scientific studies show that about 60-65 percent of all runners are injured during an average year (By definition, an "injury" is a physical problem severe enough to force a reduction in training).

When compared to many other endurance sports, the risks associated with running are higher. For example, runners miss about 5-10 percent of their workouts due to injury, while racewalkers are absent just over 1 percent of the time, and step-aerobics participants go AWOL with a frequency of less than 1 percent ("Incidence and Severity of Injury Following Aerobic Training Programs Emphasizing Running, Racewalking, or Step Aerobics," Medicine and Science in Sports and Exercise, vol. 25(5), p. S81, 1993).

Still, running is far from being the most injury-producing sport. In recent study in the Netherlands, running ranked fourth-behind outdoor soccer, indoor soccer, and volleyball - in the total number of injuries produced per year, and whne injuries were expressed per hour of actual activity, running was well down the list - in 14th place (Sportblessures breed Uitgemeten, Haarlem, DeVrieseborch, 1990).

 In addition, running's 65-percent-injury and 5-percent-absence rates could be significantly lower - if runners knew more about the actual causes of injuries and made a few simple adjustments in their training schedules. In fact, research suggests that running injuries could be cut by around 25 percent (Sport for All:Sport Injuries and their Prevention, Council of Europe, Netherlands Institute of Sports Health Care, Oosterbeek, 1989).

Lets identify where injuries are likely to occur. The five anatomical "hotspot" for running injuries are: (1) The knee (25-30 percent of all running injuries occur ther) (2) The calf and shin (20 percent of all injuries) (3) The ilio-tibial band - a long sheath of connective tissue which runs from the outside of the hip down to the lateral edge of the knee (10 percent) (4) The Achilles tendon (8-10 percent) (5) The foot - the focal point for hobbling injuries like plantar fasciitis (10 percent)

To learn how to minimize your injury risk (the full article can be read by purchasing Vol.9 Issue 5) and many more running related topics. Simply enter What You Don't Know About Running Injuries Can Hurt You, in the "search archives" box, or enter any subject you wish to learn more about. A subscription to Running Research News is another way to receive valuable information. SIGN-UP NOW

Part one--Why Rank and File Runners Should do Resistance Training

The year I turned 20, I graduated from junior to senior grade as a distance runner in New Zealand.

Now I would be running the 3,000-meter steeplechase against seasoned steeplechasers who were faster and stronger than me and chewed us young steeplechasers up for breakfast.  However, my running was maxed out--any more and I would have injured myself.  So I asked, 'What could I do to get within range of these guys?'

A friend suggested I try weight training to make myself stronger.  Maybe that would help? With nothing to lose I started lifting weights three times a week. I felt very strong during my races and my steeplechase time came down by 15 seconds.  I even managed to get to the New Zealand Championships in the senior race.  Since then there has been no doubt in my mind concerning the positive effects of strength training on distance running performance.

The majority of non-elite runners do not strength train to improve their running performance.  Strength Training Will Improve Your Running

Because of the time consumed by running, most runners cannot find the time or do not have the interest to lift weights, while many do not think it will help them race faster.
However, of all the sports endurance events, distance running has the most impressive research results to support weight training as a technique to improve your running.  It is a given that elite runners these days lift weights as an integral part of their training regime.  They will all tell you that strength training has made them faster.

The irony here is that research shows weight training has a greater improvement on unfit or less fit runners than elite runners in the parameters of anaerobic threshold, running economy, and neuromuscular characteristics. That’s right--if you’re a runner doing 20 to 50 miles per week, you stand to gain some marvelous improvements compared with elite runners.

A study done a few years ago found that trained runners improve their running economy from 4% to 8% with resistance training.  Even small improvements in running economy can have a large impact on longer distance events such as the marathon or 10K races.  A 4% improvement for a 41:39 10K runner would reduce this time by 100 seconds.

But what about the rank and file runner, with 10K times between 35 and 60 minutes?  Can resistance training help this group bring their times down?  Several studies have shown that recreational runners who lift weights improve their performance.  One study found lactate threshold, or the point where you start accumulating significant amounts of lactic acid, to be increased after a period of resistance training in untrained individuals. 

Many studies of elite runners have not found this benefit from resistance training--indirect proof that rank and file runners have more to gain from strength training than elite runners.
But the study I believe to be the most promising looked at novice cycling and running trained subjects who added strength training three days per week for ten weeks.  The results were exciting.  Strength Training Will Improve Your Running

The participants improved leg strength by an average of 30%, but thigh girths were unchanged, meaning they did not add any muscle bulk--something that would slow distance runners down.

And although their oxygen processing abilities were unchanged (as you would expect to find in people doing weight training), their cycling and treadmill running times to exhaustion at 80% of VO2 max were lengthened from 71 minutes to a staggering 85 minutes.  Even their short-term high-powered (maximal 4 to 8 minute effort) endurance cycling and running were lengthened by 11% and 13%.  In addition, six of the eight runners in this study improved their 10K times from an average of 42:27 to 41:43.

Other research has found similar results. Thus it is clear, that weight training can help you run faster for longer with the same effort and oxygen consumption.  Attending a sports medicine conference recently, I heard one speaker make a comment that rang true.  The athletes who are winning these days are ones who can maintain high wattage for longer than their competitors, i.e., they sustain their power at a high percentage of their VO2 max--now acknowledged as a major contributor to success in endurance events.Strength Training Will ImproveYour Running

The question is, if you are a recreational runner spending two to three extra hours each week doing weight training, would you be better off spending this time running?  Will weight training adversely affect your running?  And will weight training make you tighter and less flexible?  The answers are no, no, and no.  In one study, coaches were surprised to find that substituting 32% of total endurance training in elite distance runners for strength training improved runners' 5K performance significantly. 

Other research demonstrated that strength training does not reduce endurance performance in non-athletes. 

Studies investigating the effects of weight training on flexibility found weightlifters possess average to above average flexibility in most joints.

So how, then, does strength training actually improve running performance?  The theory goes something like this.  Your running speed is dependent on the force applied to the ground during each foot strike and the time over which this force is applied.  The faster and more powerful the foot strikes, the faster you will run.  Thus, if you improve the power you exert during each of your steps, you will run faster. Strength Training Will Improve Your Running

Resistance training improves the tensile strength of your leg muscles, and thus enhances the recoil or return of energy with each foot compression or step.  Additionally, your neuromuscular system becomes better coordinated from resistance training, enabling you to run using less energy and less oxygen.

A typical comment heard from runners I have coached who have taken up weight training is "I'm able to finish 10K races with a longer, sustained drive, and strong finish."  Others claim that strength training has helped them relax their arms during the early and middle stages of their races.  Women in particular have a lot to gain because they tend to be 20% to 40% weaker than their male counterparts in the major body regions (legs and upper body strength).

Other major benefits that weight training are theorized to have for runners includes injury prevention, correction of muscular imbalances, increase in stride length, improvement in core stability, and increase in basic speed. Although there is not yet enough evidence for all coaches and exercise scientists to agree on, these aspects should not be completely ignored and today are accepted reasons why coaches ply their runners with strength training.

Here, for example, is how resistance training can help prevent injuries.  Lifting weights may help correct imbalances and biomechanical deficiencies such as the ratio of strength between the quadriceps and hamstrings groups. (Hamstrings tend to overpower quadriceps in distance runners.)Strength Training Will Improve Your Running

When all the research is examined, it is safe to claim that weight training is likely to improve your running, while it has never been found to detract from your performance.  Now that I have sold you on its benefits, here is some practical advice on what to do and how to do it.

Part Two--Weight Training Advice and Programming for the Runner

There are several different types of resistance training equipment available in your local fitness club--free weights, Universal systems, Nautilus, Cam Systems, etc. They use different types of resistance, e.g., air pressure, fluid resistance, friction, pulleys, gravity, etc.  Which of these is best?  It does not matter--as long as you are pushing or pulling against resistance and overloading the muscle, you will gain strength.

Ideally, a combination of modes is best, so try using a mix of free-weights and fixed machine equipment.  Your workouts should only last about 45 minutes to an hour, including warm-up time and stretching.

How do we go about improving our strength?  We must overload our muscles with a resistance that is slightly more than we are used to pushing or pulling.  Resistance (or weight) should be increased every few workouts or weeks and not every workout.

General sequencing strategies include using multiple-joint exercises before single-joint exercises.  Work your large muscle groups before small muscle groups.  This way you will not pre- fatigue your small muscles, which would make it more difficult to work the larger ones later.  Do heavy weight training exercises that require greater force before lighter exercises, for the same reason. Strength Training Will Improve Your Running

If you can manage three to four workouts with weights each week, I would recommend a split workout, where you alternate exercising the upper body with the legs and trunk.  To achieve balance between muscle groups, alternate pushing exercises with pulling exercises on the opposite side of the body.