Cross training: sport-specific workouts to boost your performance

Endurance athletes are diversifying: swimmers are cycling and lifting weights, cyclists are doing more running, and runners are taking up stair stepping, cycling, and resistance training. Can such "cross training" workouts really help athletes in their preferred sports? Does being a better cyclist automatically make you a better runner, too? Owen Anderson provides some answers

There are three ways that cross training might help you:
(1) Improved leanness: Doing some cross training can help you burn more calories per week. For example, runners who maintain their usual running schedules and add one 30-minute cycling workout per week can lose one extra pound of fat every 10 weeks, provided they don't increase their food intakes. Over the course of a year, that's about 50 additional cycling workouts and five pounds of lost fat. True, such runners could simply run 30 minutes more per week, but heightened running mileage often leads to injuries, whereas time spent on the bike is seldom damaging. The vanished corpulence that comes from the 30 minutes on a two-wheeler can make a big performance difference. For example, a female runner who trims her percent body fat from about 17.5 per cent to around 16 per cent can carve approximately one minute from her 5-K race time, without making, any other physiological improvements at all!

(2) Greater average workout intensity: A runner who is already completing two (or three in some cases) rugged running workouts per week can seldom cavalierly add an extra red-hot running session without increasing the risk of overtraining or getting injured. On the other hand, throwing in a hell-fire bike session produces little trauma to the leg muscles and can often be well tolerated. This upswing in intensity can do two great things: it can make the heart a bigger, stronger pump, and it can hoist blood volume.
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Blood volume? Sure remember that a 5'10', well-trained endurance runner has about 15-per cent more blood than the sedentary man on the street corner. This extra blood produces performance bonuses, because it allows the heart to send more blood (and thus fuel and oxygen) to the leg muscles during exercise and more blood to the skin for cooling.

Now, bear in mind that the best way to upgrade blood volume is to perk up the intensity not the length of your workouts. You get the picture now: adding a sizzling bike workout when it would be very difficult to add in a demanding running session can produce enhanced increases in blood volume, which would then improve running capacity. Putting in the incendiary bike workouts probably also improves the 'buffering capacity' of runners' leg muscles, making them more resistant to the fatigue-inducing effects of lactic acid.

Those two very positive changes higher blood volume and improved tolerance of high work rates probably represent the mechanism underlying a startling recent study, in which 10 well-trained runners added some scalding bike-interval training to their weekly schedules. Within six short weeks, the runners improved their 5-K times by almost 30seconds,from 18:16 to 17:48.

(3) Greater strength: One form of cross training resistance training adds generalized strength to your leg muscles. As a result, fewer muscle cells need to be activated when you run at your usual race intensity. This saves energy and improves your running economy, a key indicator of running prowess. This is why recent studies have linked weight training with augmented running efficiency and improved running performances. Strength training has also been linked with higher-velocity tennis serves, faster throwing speeds by baseball pitchers, and larger-amplitude jumps among basketball players. It's a form of cross training which really works.

Why cross training CAN'T work

All of that sounds fine, but there's also a key reason why cross training should not work. As you already know, the best workouts are the ones which are SPECIFIC to the demands of the event for which you are preparing. To get ready for 5-K racing, running intervals at 5-K pace is better than long, slow running, for example. Likewise, running is better than biking at preparing for running competitions, and biking is better than running when readying oneself for the Tour de France. In that regard, cross training is a waste of time, since it can never prepare athletes as well as more specific training. The overall idea is that a cross training workout doesn't groom you for the exact neuromuscular demands of your main sport. That's because the muscular and nervous systems work in contrasting ways in different sports, with differing accents on various muscle groups. The calves are the main muscles of running, for example, but are no big deal in cycling, a sport in which the quads go full tilt.

Bear in mind that that's not necessarily such a bad thing, though. Runners who take up cycling might improve their quadriceps strength enough to become terrors at hill running, or they might improve the 'anaerobic' and buffering capacities of their quads to such an extent that they could more easily tolerate very high running speeds.

Note also that the cross-training arguments are definitely biassed toward the idea that cross training is a good thing. We have three key positives about cross workouts higher workout intensities, improved leanness, and greater strength and only one real knock against them the lack of specificity.

That's probably why scientific research has been very kind to the concept of cross training. There are now four separate studies documenting improvements in running capacity after runners took up biking. In two of those studies, runners completely substituted cycling for running; in two others, they added cycling to their existing running programmes. Other studies have suggested that stair stepping and aquarunning can do a nice job of preserving running capability when it's not possible to run.

And we still haven't mentioned the possible mental benefits of cross training. If you can learn to mentally tolerate a super-tough bike workout, you can probably better cope with the pain of running fast, too. Plus, it's important to consider the 'muscle-trauma scenario'. Let's face it, most runners do a great job of battering their legs. They run when they're tired, run when they're hurt, run so much that they never really let their leg muscles recover completely. Switching over to bike workouts can at least produce partial recoveries, because it prevents the damage which can accrue to leg muscle cells when a tired runner decides that a 20-miler is just the thing to improve fitness.

Which other sports are best for runners?

Many runners aren't sure which alternative forms of exercise are best for their running. For that reason, we've listed some popular sports or activities below, ranking them from best for your running (no. 1 ) to least beneficial (no. 11).

(I) Cycling: Narrowly edging out resistance training, cycling comes in no. 1 because of the large number of scientific studies which have shown that cycling helps runners. These investigations have shown that cycling can improve 10-K race times by 9 per cent, quicken 5-K race performances by 3 per cent, upgrade two-mile times by 1 per cent, or boost V02max by 15 per cent! Cycling allows runners to attain all three goals of cross training heightened workout intensities, improved leanness, and greater strength.

(2) Resistance training: Easy choice here. Recent scientific research has linked strength training with a 4-per cent improvement in running economy, reduced heart rates while running, and improved race times at distances ranging from the SK to marathon. Older research linked weight training with a 20-per cent uptick in endurance (at intensities which could be sustained for a little over an hour) and a 13-per cent spike in endurance when running at about onemile race pace. Resistance training probably also protects runners against injuries, and circuit training provides a decent cardiovascular workout, in addition to hiking muscle power.

(3) Soccer: A bit of a surprise here, but soccer competitions can give your running a real boost. During a typical game, soccer players travel from 9000-11000 metres, which includes 4000 metres of jogging, 2000 metres of running at a high but not maximal speed, 800-1000 metres of sprinting, 2500 metres of walking, and 600 metres of moving backwards. Soccer players' heart rates are above 150 beats per minute for most of a game, and blood lactate levels often rise to 6-10 millimoles per liter, comparable to the concentrations commonly observed during 5-K and 1 0-K running competitions. Overall, a soccer competition is like an excellent, prolonged interval workout. It's not surprising that many of the top Kenyan runners were originally excellent soccer players.

(4) Deep-water running (aquarunning): It's a strange and boring activity, but slipping into a life preserver and running in place in the water can actually help your running, especially if you're too injured to run on terra firma. In a recent study, deep-water runners who totally abstained from regular running for six weeks were able to perfectly preserve their racing ability. Aquarunning actually mimics real running more closely than cycling, but the tedium of spending time in the pool gives the activity only a no. 4 ranking on our list.

(5) Stair climbing: Stair stepping sends your quadriceps muscles' aerobic capacities into the stratosphere and transforms you into a hillclimbing demon. In a recent study, individuals who participated only in stair-climbing workouts for nine weeks improved their running performances as much as athletes who engaged in regular running sessions. If there's a negative to stair climbing, it's that actual stride rates are seldom very high even during maximum exercise, so it's hard to learn to run fast on a stair-stepper.

(6) Cross country skiing: Very much like running, but without the hard impacts. Great for losing weight, hitting high intensities, and raising muscle strength around the hip areas.

(7) Aerobic dance provides an outstanding cardiovascular workout, boosts quadriceps and hamstring strength, improves coordination, and can make runners quicker on their feet. Plus, the upper-body movements used in aerobic dance may even tone up runners' torsos a bit.

(8) Walking: It's not as biomechanically similar to running as you might expect, but walking does employ the major muscle groups required for running and can burn beaucoup calories IF you keep at it long enough. Plus, the high impact forces associated with running are much reduced.

(9) Tennis and squash: A good game can serve up a nice workout for your cardiovascular system, and these racquet sports can improve your speed and agility over short distances. Unfortunately, the start-stop nature of the games is sometimes hard on runners' knees and quadriceps muscles.

(10) Swimming: It's nice for your ticker, may improve your flexibility, and gets you off your feet for a day, giving your leg muscles a bit of recovery. (11) Golf: Just slightly better than cigar smoking

The five rules of cross training

Cross training shouldn't be approached haphazardly. Use the following rules to guide your cross-training efforts:
(I) Being in great running shape does not mean you're ready for prolonged exercise in another sport, so approach new activities cautiously. An hour on a stair stepper or two hours of tennis if you've never tried those sports before may leave you too sore to complete a running workout you've planned for the following day. When you try an alternative sport, limit your first workout to no more than 20 minutes.

(2) Don't immediately add an alternative workout to an already strenuous running schedule. If you run five times per week, adding a cycling workout (to give you six workouts per week) might transport you into a zone of fatigue and poor performances. At least initially, it's far better to SUBSTITUTE an alternative workout for one of your running sessions. You can increase your total number of weekly workouts later.

(3) Avoid activities which might aggravate running injuries. For example, runners with sore quads or Achilles tendons sometimes find that cycling aggravates those conditions, and runners with plantar fasciitis or lower-back stiffness often don't respond well to long-distance walking or court sports.

(4) To achieve maximal fitness benefits, match the duration of your alternative workouts with the length of your usual running sessions and also try to do something hard during the alternative workout. For example, if you usually run 45 minutes a day, let your cycling workouts last for 45 minutes, too, if you've had previous experience with cycling (see rule no. I above). Within the 45 minutes, throw in a couple of tough two-minute intervals, increasing the number (and length) of the intervals gradually over time.

(5) Whenever you feel tired during an alternative workout, stop! Fatigue is a sign that your body needs rest, not extra work. Remember that the whole idea behind cross training is to keep your fitness and interest in exercise high over the long term not to leave your body drastically depleted.

Two common questions

Here are two questions which are frequently asked about cross training:

Question: On a day when your muscles are too sore for running or you feel too tired to run, are you better off cross training or resting completely?

Answer: If you are PHYSICALLY tired or hurting, it's better to avoid exercise completely, because any training you do will divert energy away from muscle repair and into the process of fueling your workout. If your muscles really need restoring, that's obviously a bad thing. On the other hand, if you are physically OK but MENTALLY tired, you should base your decision on what the workout will actually do for your psyche. If the cross session will recharge your mental batteries and reinforce the idea that working out doesn't have to be humdrum routine, then by all means do it. If the effort is not going to be fun, avoid it.

Question: Why does cross training seem to be better for some sports rather than others?

Answer: It's true that the effects of cross training are specific to the main-sport, cross-sport combination. For example, cycling appears to be great for runners, but running doesn't do a hell of a lot for cyclists. This is partially a matter of muscle trauma. Running is a sport with a high incidence of leg-muscle trauma, because of the repeated impacts associated with the sport. Of course, there's no impact involved in cycling. Therefore, when runners take up cycling, it keeps them from abusing their leg muscles and may allow their leg muscles to heal a bit. This recovery process represents part of the 'bonus' which runners get from cycling. On the other hand, cyclists who add running to their programmes begin to experience impact-related trauma to their leg muscles. The damage incurred by their muscles can actually interfere with function; therefore, it's unlikely that cyclists' performances will really 'take off' after they start running, whereas runners who initiate a biking programme can really soar.

Owen Anderson