Endurance training for my next attempt at the 100km was supposed to start at the beginning of the new season in May, but a new arrival this week on the Free Spirits team with over two and a half million metres for this season has pushed me down a place on the metreboard, and had left me tantalisingly one place short of my hoped-for 50th position to end the season.

That was the reason for two 30km rows this week (one of which was supposed to be a 50km, but I didn't have the energy), and the reason for me heading to the gym this morning for another go at the 50km. First target was just to finish - no quitting today, no matter what the time - those metres were needed. Second target was to get inside the 2:00 split, even counting rests (sub 3:20:00), and a new FS club record.

It was hard work. Although I couldn't feel any after-effects of the row I did on Thursday night (including a hard 12km CTC row in 43:46.3), I wasn't sure before starting whether I was ready for another sub 2:00 split marathon or longer distance just yet. I was, but only just - I passed the marathon in 2:48:22, at 1:59.7 split, and didn't have a lot to spare.

Those extra 7805m to turn the marathon into a 50km are less easy than people might think. When 'just' doing the marathon, I always find an extra burst of energy when there's 5km or less to go, as I know I can make it to the finish, but after the same amount of distance rowed in a 50km, there's still nearly 13km to go, and today, that was the point at which I had my first real doubts about keeping the pace going to the finish.

I had a further mental battle after passing the marathon distance, but thankfully this only lasted for a couple of km before I was inside the 5km to go mark, and then it's time to just grit the teeth and get home. My final time of 3:19:14.7 (1:59.5 split) meant I'd achieved both targets, and hopefully won't have to do another full on 50km in a while (as any I do next month will be done at closer to 100km pace - around 2:05 split).

I may need to adjust my plan leading up to the 100km though. One thing I've learnt from this week is that I will need longer than two days before the attempt in order to approach it totally fresh. And I may choose not to do it on the Spring Bank Holiday weekend (when I'll be at home)... the reason being that I think it will be very hard to row for over 7 hours in my garage if the weather is hot - an air-conditioned gym will be preferable in that case. There are a couple of downsides to the gym though - not being able to have substantial quantities of food and cold drinks on hand, and not having RowPro.

I've begun to realise that my erging has reached the level at which it can no longer be described as a leisure activity, or a fitness regime, but only as an obsession. This is very evident when you consider the following:

Where normal people fit their gym sessions around their other activities, I'm now planning my erg sessions for six weeks in advance, and social activities which conflict with a session are being summarily binned.

I've relatively recently joined Facebook (www.facebook.com), an internet-based "social utility" (as it describes itself) that some of my friends use for keeping in touch with what each of us is doing. Needless to say, most of my status updates consist of my new PBs or are otherwise erging-related.

I find myself having to apologise all too often when in the company of people I know for continuously talking about erg sessions, recent PBs, goals etc.

At the moment, I still consider this to be a healthy obsession (in all senses, not just the obvious!), and I hope it will remain that way, but I know I'm going to have to keep a close eye on it, and be open to the possibility of facing criticism over the amount of time I'm spending on it.

After feeling like Superman with my sub 2:00 split marathon on Friday, today I had a rude awakening and was made to realise I'm only human after all.

I'd skipped a couple of meals yesterday and today (dinner last night and breakfast this morning... not for any particular reason - just that I happened to be travelling yesterday, and had a lie-in today). While I didn't feel any different during the day particularly, when I headed for the gym after work there was obviously going to be a difference.

I'd planned to do a first attempt at the April CTC challenge - a straight 12km row. Based on recent performances and extrapolating some further improvements, I was expecting to be able to do this in somewhere between 43:30 and 44:00 (although I'd erred on the side of caution, and only announced my target as 44:00 at best).

My next mistake was to blitz out a 3k 'warm-up' in just over 11 minutes, at a 1:51 split. By any standards, this is ridiculously fast for a warm-up - closer to 13 minutes would have been more sensible. Recently, I've been getting into the habit of warming up too fast - normally I do 5k in around 19:20 (1:56 split), though even 18:40 has been recorded for this (1:52). I think I need a big sign to hang in front of the erg that says 'I will NOT warm up faster than a 2:06 split'. Given that today I was planning a fairly long hard piece to follow, I should probably have been doing an ever slower warm-up than normal, though possibly longer - maybe 6k at 2:10.

When I started the race piece, I realised straight away that things felt all wrong. I hit the right pace or even a fraction inside it for the first 2k (1:48.7), but with my HR already up at 180, and my legs and arms feeling really heavy, I just couldn't maintain it. Successive 2ks got slower and slower, all the way down to 1:58 by 8k (and even the odd stroke over 2:00 - shocking), before I found the energy to drag it down to 1:55, and finally 1:49 for the final 2k. By my recent standards, a very disappointing 45:25.5 (1:53.7 split) for the distance.

Good Friday saw me finally hit my marathon target of 2:48:30, which was the last of the targets for the 2006/7 season that still remained to be achieved. While I'd improved my PB each time out the last few times I'd done this distance, it had still proved difficult until then to get down to that elusive 2:00 split.

In an effort to get there, the last time out I'd attempted to row it non-stop. I'd been well on target until 35km, albeit with a HR running at 170+ for over 2 hours, and then blown up quite spectacularly, doing a feeble last 7km to limp home in 2:50:46.9, even though this was a new PB by 3 minutes. This led me to the conclusion that trying to row a marathon non-stop is a VERY BAD IDEA, and I decided I wouldn't be doing this again.

I'm quite comfortable rowing a half-marathon without a break however, so I felt I should only need one break during the full distance. The problem I find with this, however, is that it's almost impossible to take a worthwhile break and get a decent amount of fluid on board in less than a minute, which means you need to factor this extra minute into your split calculations.

To hit my target, I therefore needed to row two half-marathons in 1:23:45 each, and I set off with this pace (or just inside it, as I normally slow down at least a little in the second half) in mind. HR-wise (high 150s/160 mainly) and raceplan-wise, this went much more smoothly than any previous attempt, and I reached the halfway point about half a minute up, at close to 1:23:15, and still felt pretty good.

The second half was a little more mentally demanding, and the split fell off just a little, while my HR rose to low 160s average, but it never looked like I was going to fail to finish inside 2:48:00. A big sprint finish for the final 2195m got it down even further (and actually made the second half quicker than the first by some 30 seconds), and I finally came home in 2:46:54.7, a new PB by almost 4 minutes, and a 1:58.7 split for the full distance (including the rest break).

The 2:00 split is still very demanding, and I don't expect to be able to repeat this performance on demand. Everything went right - I ate well (and substantially) the night before, was well hydrated, normal heart rate. Conditions were good - not too warm in my garage at home, and enough of a breeze to get a good through draft to keep me cool.

I still needed several hours of rest afterwards, and could feel it in my quads, biceps and abs the following day, but with the exception of my hands, which had developed a whole series of blisters and 'hot-spots' at the top of each palm, I felt I could have done a decent session the day afterwards without too much hardship, though not at anything like the intensity of the marathon.

If I'd failed to hit the target, I had planned to have another go on Easter Day, but I'm very glad I didn't fail, as I doubt that I could have rowed at anything like the required pace for a second marathon in three days.