Coke vs Pepsi. The Rolling Stones vs the Beatles. Apple vs Microsoft. These rivalries are small fry when compared to the daddy of them all: aerobic vs anaerobic training for rugby. The pendulum of popular opinion has swung back and forth between these two for decades now.
Once upon a time nothing but aerobics was the way forward for rugby performance: long slow runs and aerobic interval training were the order of the day. Nowadays it seems the anaerobic conditioning is enjoying the spotlight; Tabata intervals, gassers, suicides abound. Bring your vomit bucket! So which method is best?
In previous years I made the mistake of planting my flag in only one camp on a number of different issues: Olympic lifts, back squats and speed technique drills to name but a few. However today I want to state at the outset that a combination of both aerobic and anaerobic methods will be required to achieve optimal rugby performance. However in my opinion rugby athletes should lean heavily toward aerobic means in their preparation. Let me tell you why:
I like to use the analogy of a business when describing the training process. Just like a business only has a certain amount of capital to invest, we can only invest so much time and effort in the training process. And just like the most successful businesses are built on investments that offer the greatest return, the best training programmes invest training time and effort into the training means that produce the greatest return- in this instance power output on the field.
A quick look at the science books should tell us that aerobic methods are superior in this regard. In Dr Vladimir Issurin’s text “Fundamentals and basics of advanced athletic training” he lists the trainability of aerobic factors and anaerobic adaptations. With aerobic means it is possible to boost aerobic enzyme content by as much as 120% percent, maximum cardiac output by 75-80%, and mitochondrial density by 95-100%; pretty huge returns.
The numbers for anaerobic training means are not so encouraging. With training it is possible to improve peak blood lactate accumulation by only 20%. Anaerobic enzyme content might be boosted by as much as a third. These are pretty poor returns, especially when you consider the effort that has to be expended in pursuing them, and the longer lasting fatigue such training creates.
In another chapter of his book Dr Issurin examines the heredity of anaerobic vs aerobic development i.e. how much of your ability can be achieved through genetics vs smart training. For aerobic exercise the heredity is pretty small- about 30% of your ability to do aerobic exercise is down to your parents. The rest is down to good old fashioned training.
Conversely anaerobic exercise performance is 2.5 more attributable to genetics at 80% heredity. This means you can do all the anaerobic training you fancy, but unless you have the right genetics, your rate of improvement will be disappointingly low. This is doubly frustrating when you consider how physically and mentally taxing anaerobic training can be.
Take the easy route to the destination
I freely admit that aerobic training can occasionally be boring and require a lot of effort, but it is nothing compared to anaerobic training! Your legs burn and turn to jelly, your lungs feel like they’re on fire, and you feel like you want to puke and mess your underwear at the same time.
I am not saying you should wrap your athletes in cotton wool, but if you are presented with two ways to achieve a performance outcome, take the easier of the two. If you really wanted to, you could crawl 100 miles on your hands and knees. Or you can take a bus. Both options will see you arrive at the same destination, but one requires much less effort and suffering than the other. You might get more kudos if you pick the tough route, but my athletes and I don’t care.
We forget that not all athletes are masochists like their coaches. For some players- especially professionals- conditioning is a tiresome job that must be endured, not enjoyed. If that is the case, make the process as painless as possible for all involved.
In preseason anything goes; you can train however you like without consideration of long technical sessions, travel, playing matches and having schedule messed with by the weather and/or overly enthusiastic coaches. But once you get into the season, everything gets turned on its head. With such a strong emphasis on being fresh for matches, recovering from matches and dedicating training time to technical and tactical training (which changes on a weekly basis), it is a harsh reality that athletes will lose fitness during the season.
However not all abilities are created equally. Training residuals- the time for which the body can hold on to most of a particular ability- vary greatly. Some adaptations like bone density, gross motor skills and connective tissue strength last for years without any training. Others like speed endurance and peak power output start to slip after only a few days.
In the middle sit aerobic and anaerobic factors. Anaerobic residuals last from as little as a few days to a few weeks- not very long. Some aerobic factors like aerobic enzyme content and glycogen storage may only last a little longer than this, but a great deal of aerobic factors can be retained for months or even years e.g. cardiac dimensions, muscle capillarisation and mitochondrial density. If I know my athletes are going to lose fitness- and they will if they are of a high enough level- I would rather invest training time in those abilities which will allow them to lose fitness as the slowest possible rate.
Maybe it is down to limited trainability, maybe it is other factors, I don’t know; but I do know that the point of diminishing returns arrives far sooner with anaerobic training than aerobic training. You have to look no further than the famous Tabata study to see an example of this.
Tabata et al. (1996) is the study which anaerobic aficionados cite to demonstrate the superiority of such intervals over aerobic training. But what most critiques of the study omit is that whilst the anaerobic interval group improved their performance, they hit the wall before the study was even through. In less than 6 weeks, the Tabata intervals ceased to be useful. In the other group which performed conventional aerobic training, the performance improvements were smaller, but continued to the very end of the study.
What happens if you only select anaerobic intervals, but the season is longer than 6 weeks? Do you just hit the wall, then bang your head against it until the off season arrives? I would rather squeeze every last drop out of aerobic adaptations first, then use a more unpleasant scheme like Tabatas only when necessary to ensure that my athletes keep improving throughout the season.
Better athletes produce less lactate
Imagine for a second that a world class player like Quade Cooper dropped down to the junior level. Do you think Quade Cooper would produce more or less lactic acid than normal during the course of the game? The obvious answer should be no. He is going to rely less on the lactic acid energy system much less, because his aerobic and alactic energy systems are so well developed relative to the demands of the game.
With my athletes, I am trying to create this scenario. I am trying to train up their aerobic and alactic energy pathways to such an extent, that they can play the game whilst producing hardly any lactate. It is true that anaerobic training can improve aspects of rugby performance, but at what price?
Of course, anaerobic training will improve tolerance of lactic acid, but there is plenty of research to suggest that anaerobic training hinders the aerobic system and diminishes peak power output in maximal efforts like sprinting, jumping and tackling. These are vital skills in a rugby athlete’s arsenal and it seem illogical to me to train in a manner which might harm power output in these skills.
Consider also that the aerobic and alactic systems work in a mutualistic fashion; better aerobic development improves resynthesis of creatine phosphate, and is also a stronger predictor of repeated sprint exercise than glycolytic development. With higher aerobic development any lactate produced will be metabolised more quickly, improving recovery between matches, and between maximal efforts during the match itself.
The bank account
I like to use the analogy of a bank account overdraft when describing the glycolytic energy system; it is there if you need it, but it wont last forever. If you choose to use it, there is a price to pay. If you use it again and again, without paying back the debt, expect to go bankrupt. Similarly if an athlete is forced to rely on glycolytic energy production, peak power output, motor control and decision making are all going to suffer. If you fuel exercise using glycolytic metabolism for too long, eventually you will either have to stop or slow down.
Just as with an overdraft, it is best to use it as little as possible. Save it for a rainy day- save glycolytic energy production for those rare occasions when a well develop aerobic and alactic system cannot meet the demands of the game.
I could go on but I fear the analogy well has run dry!. I repeat: I do think there is a place for anaerobic training in rugby strength and conditioning but it comes with several caveats. It has to be selected and monitored carefully, used sparingly, and implemented only when a high level of aerobic fitness already exists.
Let’s do away with the notion that suffering equals productivity. Running yourself into the ground is not the fastest, most productive way to enhance energy system output on the field. I think the arguments I have outline below demonstrate this, but I am sure my opinion may change some years in the future when the pendulum swings back the other way. We will have to wait and see.