Source from Coolrunning Thread

What athletes should do when their quadriceps muscles start going downhill.

The answer, of course, is to let your quads go downhill. No - we don't mean you should allow your quads to become weaker; we want you to expose your quads to some downhill running. A judicious amount of well-timed downhill running can actually help prevent leg-muscle soreness, especially in your quadriceps muscles.

Normal training for your sport, of course, protects your quads to some extent; the quads simply get used to a certain level of eccentric action. However, if you run more than you usually do because you are involved in a major match or serious preparatory workout, your quads won't be fully prepared to handle the extra stress. If you run faster than you usually do, your quads will also be prone to trouble; increased limb acceleration heightens impact forces in the leg and forces the quads to work harder (and more quickly) to control knee flexion.

That makes downhill running sound a bad idea, but in fact the small-scale controlled damage associated with well-regulated downhill efforts actually forces your quads to adapt and strengthen themselves so that they will be more immune to damage during subsequent challenges. Think back to the first serious workouts you ever carried out in your sport, for example. Your muscles were undoubtedly sore the following day, and perhaps they were painful for several weeks whenever you undertook particularly challenging training sessions. Gradually, however, you developed the capacity to work at high levels without incurring much soreness; your muscles had adapted to the strain produced during your training. Downhill running gives this adaptation process a special boost, so that it will be hard to damage your quads - even when you go beyond your usual training limits.

The six-week factor.

Amazingly enough, just one downhill workout can furnish decent protection for the quads, and the 'soreness insurance' provided by a single bout of downhill running can in some cases last for six weeks or more. Several years ago, scientists at the University of Massachusetts asked 109 individuals to perform two sets of 35 maximal, eccentric contractions of the biceps muscle in the upper part of one arm. Basically, these eccentric contractions consisted of lowering a very heavy weight, which forced the biceps muscles to elongate as the weight was lowered; simultaneously, biceps-muscle fibres were attempting to shorten to stabilise the weights movement.

The biceps muscles were clearly damaged by the eccentric workout (we won't hurt your legs to this extent with our recommended downhill sessions below, because we don't want you to lose 10 good days of training), but they adapted very nicely. When the individuals tried the same biceps routine six weeks later, there was appreciably less soreness and little loss of muscle strength, even though there had been no intervening biceps training. The biceps muscles were somehow protected from problems as a result of that initial eccentric session.

The Massachusetts researchers speculated that a strenuous bout of eccentric exercise 'teaches' the nervous system how to better control and distribute the forces that are acting on particular muscles. In theory, this lessens the strain on individual muscle fibres when eccentric activity tries to tear them apart and thereby reduces muscle damage and consequent pain. Just as the nervous system can learn to do this, it can also forget, and this forgetting seems to take place after slightly more than six weeks (bear in mind that the rate of forgetting may depend on the severity of the initial workout; a 'timid' eccentric workout might be forgotten after four weeks, while a strongly fibre-damaging one could be retained by the nervous system for a couple of months).

A key finding was that the quadriceps muscle cells of the decline-trained rats contained almost 10% more sarcomeres per cell, compared to the quads of the inclined rodents. To understand what sarcomeres are, bear in mind that a muscle cell is a barrel-shaped structure, and each 'barrel' is filled with several hundred to several thousand cylindrical, threadlike structures called myofibril. To picture this, simply imagine a pipe-shaped structure (the muscle cell) stuffed with countless numbers of small cylindrical wires (the myofibril). Incidentally, when we say that a muscle cell is shaped like a pipe, we are referring to a section of cylindrical water pipe, not to a pipe used for smoking purposes.

As mentioned, downhill running induced the muscle cells to add more sarcomeres to their myofibrils. Why is this increase in number of sarcomeres beneficial, and how can it prevent muscle damage and soreness? Since muscle-cell length itself didn't change significantly as a result of the downhill running, the fact that there were more sarcomeres per muscle cell meant that during eccentric contractions, when the whole muscle cell was elongating, each sarcomere in a downhill-trained muscle would have to elongate less, and thus each sarcomere would be less likely to sustain internal damage.

Thus, when you run downhill, you're giving your muscle cells a wake-up call to start tacking on more sarcomeres. The increased sarcomere density then reduces stress on the myofibrils and protects you against soreness and damage accruing from future downhill running and very tough or prolonged workouts and races (if the Massachusetts neural theory is also correct, your nervous system also helps out by distributing strain more effectively and evenly throughout your muscles). Since damage is lessened, it also means that you can recover more quickly from very severe training sessions and competitions - and be ready for subsequent quality work more quickly than the poor oik with fewer sarcomeres.

Here's what to do.

So how should you actually carry out your protective, downhill workouts? Once a week for about four weeks, go to a hill which slopes downward for 50 metres or more; for your initial workout, choose a hill with a very modest declination of about 3 to 4% or so; you can increase the severity of the grade later, after you have become a seasoned downhill runner. After a good warm-up, begin carrying out 'reps' which consist of nothing more than running down your chosen slope. At first, don't attempt to run rapidly; simply use a customary training pace. Each time you get to the bottom of the hill, turn around, jog back to the top (the ascents are not noted for their soreness-reducing properties, but they are nicely strengthening for all the muscles in your legs), and continue. For your first downhill effort, maintain this pattern for 10 minutes, giving you slightly less than five total minutes of downhill running (ascents usually take longer than descents).

Your quads' behaviour during the 48 hours after this initial session will provide you with much information about their eccentric strength and soreness-resistance. If they flare up with considerable pain and stiffness during this follow-up period, you can derive some measure of comfort from ibuprofen or some similar non-steroidal anti-inflammatory medication - and from knowing that your quads really needed this training and will truly be stronger in the future (once healing has occurred). Your next workout - carried out after about a week - should be exactly the same as the first, and you will notice considerably less quad complaining after this one. Like the athletes who experienced no troubles after the initial, 10-minute downhill trial, you will then begin to gradually increase the amount of time you spend on the hill. Expanding the total hill running in three- to five-minute increments per session works well for many athletes. For example, you might choose to progress from 10 total minutes of running (including downhill and uphill) to 14 minutes for the next workout. If there are no serious problems, you could move to 18 minutes for the subsequent session, and so on. You may also choose to upgrade the speed of your downhill running, within reason, and you may want to begin utilising a steeper hill (avoid severely steep slopes which dramatically change your running bio mechanics, however). You may continue this overall progression for longer than four weeks, if you like, but a four-week programme (with one hill workout each week) should fortify your quads against unusual pain for at least six weeks after the fourth workout - and probably longer.

Recent research indicates that you can manipulate your stride lengths slightly to reduce the soreness associated with your initial stab at downhill training but that you will eventually have to 'pay' your soreness bill unless you continue to understride on hills. In an investigation carried out at the School of Sport, Health, and Exercise Sciences at the University of Wales in Bangor, 18 male runners (average age 21 years) ran downhill using their preferred stride lengths, extra-long stride lengths (overstrides), or abbreviated strides (understrides). Two weeks later, the runners ran downhill again, this time using their preferred stride lengths. Muscle strength and soreness were assessed after each bout of running ('Effect of Stride Length Manipulation on Symptoms of Exercise-Induced Muscle Damage and the Repeated Bout Effect,' Journal of Sports Science, Vol. 19(5), pp. 333-340, 2001).

No! After the second bout of downhill running, which occurred two weeks after the first, the initial understriders retained strength just as well as the normal striders and overstriders, indicating that the initial, pain-reducing understriding did not interfere with the quads' ability to maintain usual strength levels after eccentric exercise. However, the initial understriders were least protected from soreness associated with the second bout of running; they had to pay their pain bill as soon as they began to run normally! For this reason, we recommend simply using your normal strides as you run downhill; don't try to consciously minimise stride length as part of an effort to control soreness. Control post-exercise pain by utilising reasonable, non-excessive workouts, not with running-form adjustments.

Perhaps the best way to protect your hamstrings from pain is to carry out high-bench step-ups with regularity. To do these, begin from a standing position on top of a knee-high bench or step, with your full body weight supported by your left foot. Your right foot should be free and held slightly behind your body. Lower your body in a controlled manner (in effect doing a one-leg 'squat' with your left leg) until the toes of your right foot touch the ground, while continuing to support all of your weight on your left foot. Return to the starting position by applying force to the bench or step with your left foot and by straightening your left leg. Repeat for a total of 10 reps, and then switch over to the right leg. It is critical that you maintain absolutely upright posture with your trunk throughout this entire movement; avoid the tendency to lean forward for balance as your 'trailing' leg drops toward the floor.

The calf muscles.

To improve eccentric strength of your calf muscles, simply carry out single-leg heel raises on an inclined surface. To do these, stand with relaxed, erect posture on a slightly inclined surface (a pavement on a moderate hill will work, in case you don't have a special inclined board), with all your body weight supported on your right foot and your right knee barely flexed (your left leg should be flexed at the knee so that your left foot is off the ground and your left shin is roughly parallel with the floor). Contract your right calf muscles as strongly as possible, so that your right heel rises vertically off the ground and you rock forward on your foot, supporting full body weight on your toes and extreme forefoot. That's the beginning position for your one-footed heel raises.
Now, let your right heel move back toward the ground smoothly, evenly, and swiftly. Don't collapse your ankle, don't let your foot wobble from side to side, and don't let your upper body jerk around - just drop your heel toward the ground quickly and efficiently. As you do this, body-weight support will shift from your toes and forefoot to the mid-foot region.

In your first stab at this exercise, continue on for about 10 to 15 more reps on your right foot, and then give your other calf a chance to join in the fun, completing an identical number of reps on your left side. As you perform the exercise, move rhythmically and without any hesitation in the overall movement (except for the two-second 'holds' on tiptoe), and try to maintain good balance, posture, and stability at all times (initially, you may grab a wall, fence, or other structure for support if you are having trouble with your balance). Attempt to maintain a running-specific posture at all times, and try to sustain a 'feeling of rhythmic, relaxed running' as you rock back and forth on your foot; don't scrunch up your upper body, and don't look down at your legs as you carry out the movements.
So what's the bottom line? When you carry out your pain-preventing downhill training, it's nice to remember that your uphill climbs are enhancing your economy, and your downhill runs are having a profound impact on your leg-muscles' eccentric strength and ability to stand up to hard training. By running downhill, you are adding sarcomeres to your leg-muscle cells, and those additional sarcomeres should quicken your strides and help keep you free from injury and soreness in the future. In addition, carrying out high-bench step-ups and one-leg heel raises on an inclined surface will protect the 'back' sides of your legs. The freedom from injury which you attain will allow you to train and compete more consistently and thus become a much better athlete.