When you are doing your long low intensity rows, you are asking your muscles to generate a certain amount of force. Despite the slower splits, actually this force is not as low as you might think because the rate is well below race rate, requiring an increase in power to compensate. However the load is certainly not high. Your nervous system chooses which fibres to use each stroke (it does not need to use all them each time… you are not weightlifting). It will cycle around the fibres letting the tired ones rest and recruiting those which are less fatigued. However your body is well aware of the fact that your fast twitch fibres produce lactic acid, and it prefers to avoid using them. Great news, you say. Why suffer with higher levels of lactic acid if the fatigue resistant slow twitch fibres can handle the job. The problem is that these fast twitch fibres are avoiding doing any work… which means they are avoiding being trained… which means they do not improve.

So how do we get the fast twitch fibres off the sofa and into the gym. That’s easy – increase the force. A muscle than can produce 100kg of force might be able to cope by cycling round the slow twitch fibres at a force of 20kg per rep…. but how about 30kg per rep… or 35kg. Eventually the rate at which the slow twitch fibres are cycling round is fast enough that they are not able to recover. They start getting tired, producing lactic acid themselves, and the fast twitch fibres start to get sucked into the mix to help out.

During a 30r20, you are producing much higher levels of force than during your normal distance row. The fast twitch fibres might be able to sit it out for the first 5 minutes (indeed the first 5 minutes of an even paced 30r20 is not too bad)… but you can see where this is going. The fast twitch fibres are now being asked to work aerobically, and they do not like it…. so over time some of them adapt. The mitochondria within them (as few as there may relatively be) start to grow and divide. The enzyme levels in the cells (which “decide” whether to load acid into the mitochondria or not) change. Over time, these muscle cells can adapt to become better “aerobic workers”, and to produce less lactic acid… and that means you can work harder in your 2k race because your muscle as a whole is now producing less lactic acid than it was.

Of course, this is not the only reason for doing 30r20s. A really hard 30 minute piece at any rate is beneficial if it fits into your training program in the right way, but that is beyond the scope of this article. Further, although a 30r20 is not the same as lifting weights, it certainly does not hurt power production. Not only are there physiological reasons for the session, but undoubtedly mental ones as well. These rows are tough… if done properly they are really really tough. You are effectively giving your muscles a lactate bath, with the acidity getting progressively worse and worse. Different people push themselves to different points, but at 14 minutes to go most people are in a whole world of hurt… lactate levels are very high, get there is still a considerable distance to go. Both body and mind get a work out that is not easy to forget.

One of the aspects of these rows that adds to their unpleasantness (and effectiveness) is that if you are seeking to maximise your score (and you certainly should be), you cannot sit slower than average pace for most of it and put in a sprint finish. The effect of the rate cap (which incidentally means 20 strokes every minute, not just an average over the 30 minutes) is that it is very hard to find much of an acceleration at the end at all. Accordingly you have to sit around your target pace the whole way… there is no escaping it.

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