John Brooks: Firstly massive congratulations to you and your colleagues on the new Training Guide. Truly excellent and destined to become a classic training reference document (if it isn't already) and not just for rowers either. I haven't read it all in detail yet but already I have a question on the test you refer to in section 3.11 to determine MHR and AT. The MHR test seems pretty straightforward but I'm not clear whether in the AT determination I should increase the workload every 15 secs or every 90 secs. Also, how important is the stroke rate in these tests? ie should I try to keep the stroke as constant as possible as the pace increases or can I just use the rating that seems right at each workload?Terry O'Neill: Yeah, I'm pleased with the guide, it took a bit of time but I think it was worth it.As to your question, the heart rate increases in direct proportion to an increase in work up to a point. At this point the heart rate still increases but not linearly to the increase in work. This point of deflection corresponds closely to the anaerobic threshold. Its important to keep the incremental steps the same and we recommend 25watts which is close to 1 met.You need to record the heart rate every 15 seconds but increase the pace (watts) every 90 seconds. One thing is if you only want to find your AT then you may want to increase the time between each step up to 3-4 minutes. This is because at the step up the heart rate will increase but should come back down slightly and stabilise. Sometimes this stabilisation can take longer than 90 seconds and so the experts use 3-4 minutes to be on the safe side.