weights won't do a massive amount for what you need, if you do do weights for stamina you need high reps with fairly light weights.  Best thing is probably interval training on your bike or on an excersise bike. Cruise, then sprint, cruise to recover, then sprint, cruise etc.  You want to start by cruising for about 3 mins, then sprinting flat out for 20 seconds or so, over the course of a 40 minute ride, then you can wind it up to whatever time length you want to sprint for maybe up to 5 mins but you want to make sure you cruise for long enough to recover so this time should go up in relation to it if you get my drift, I wouldn't sprint for much more than 30% of cruising time as this will hurt.

It does hurt and it requires alot of will to push yourself abit, but it's a massively effective way of improving riding power, stamina, sprint power, aerobic fitness, recovery time and increasing the span of your max/min heart rate. It's probably the best way to get fit full stop, let alone just for riding, hope this helps. You should notice improvements pretty dam quickly.

I'm sorry, but there's quite a lot of inaccurate information in there and vagueries.

The starting point you have to remember is how long the event you're training for is: about 40 seconds. You don't need a massive amount of cardio fitness for 4X, as Martin Ogden lighting up lies testament to.

For a start, for 4X weights can help, if you do them right. Things like bears and pliers squats develop power really well, as do straight squats and deadlifts. If you can get your hands on the boxing power training machines you'd do well (I can't really describe it over the internet). You need to avoid short sets as they do just develop single rep strength, which is useless outside the gym. If you aim for 10-12 reps with a decent weight (ie. to fail one the last rep) you should do ok. The idea of doing lots of light weights is largely a nonsense and for a power sport, which 4X is, your time would basically be wasted.

For intervals I'm not sure what he's suggesting. The basic rule for intervals is 2:1 - for every period of exertion you should balance it with twice as long rest (ie. for a 20 second sprint you should allow a 40 second recovery period). You also need to warm up and cool down properly either side as you'll (hopefully) be working at a high level of exertion. Before you do the intervals I'm about to suggest you should make sure you're fit enough to do 30 mins exercise at a reasonable level of exertion. I personally use the rowing machine as it's a full body exercise, whereas an exercise bike is legs only (and if you think about 4X, you should be using your whole body). 10 mins warm-up, simple, break a little bit of a sweat, but just go steady to get your muscles working and heart rate up. Then go for 100m absolute flat out, as hard as you can, this should take about 20 seconds, then 40 seconds recovery time before you repeat (you should be able to programme the rower to do all this for you). In all you want to aim for 8 sets (8 x 100m sprints). Then ten minutes cool down similar to your warm up and then stretch out thoroughly. You can easily switch up to say a 150m sprint. Do this once or twice a week for a month and you'll see gains in your power, don't do it more as you can overtrain fairly easily with these. After a month take a week off as your body will need the rest. Make sure you switch your routine fairly regularly as your body will get used to them and you won't get the most out of your training - I tend to do a month of intervals, then a week off followed by a week or two of straight sets (20/30mins pretty much straight) before going back to intervals (or at least I would if work, life and laziness didn't tend to get in the way).

This will hurt if you're doing it properly, expect to retch. You do need to make sure you technique is good as you can injure yourself doing this - the most important thing is your back and you can do it in very easily doing this wrong. I'd also recommend switching the rower to display your wattage rather than speed, as the power you're generating is the most important thing.

Do I need to mention that you need to eat and rest properly - take at least one day off a week from all exercise and try and get 8 hours sleep a night. If you want to take your racing seriously, think about when you do your training so you compete when your body is at the best possible point and not battered from intervals or weights.

If you want to train on the bike I can't recommend BMX tracks enough.

Anyway, I've written enough, hope this is useful.

He's talking about doing 4x though. And most UK tracks would probably be 40seconds worth of sprinting.

Find a football or rugby pitch and do 2 minute runs.  Start of doing a lap and a half, finishing in the same corner everytime but starting further round.  It was the backbone of our pre season rugby training (i.e do a few, play touch, couple more, tackle bags, 2 more etc...).  It's tough as f**k but really helps fitness. You have to push yourself to go further back each time tho, even if its only 10m or so.  The most infit guys on our team were doing almost a lap and a half of a rugby pitch 8-10 times in one 2 hour training session as well as other training.

He was asking for help specifically regarding sprint and stamina and the advice i have given IS useful thanks very much, its helped me no end, it seems you're not called geek boy for nothing.

I think you should probably wind your neck in, poppet. I've already explained where and why you're wrong, if you fancy actually giving useful advice or rebutting something I've said specifically I'm all ears. He asked for specific sprint and stamina advice, which you didn't give.

Also, Alan Milway's got a really useful website: www.mxfitness.co.uk which is worth a good read.