In reply to ebdon:
Are you taking lighter weeks?
Effective training requires you to work hard enough to create an overload that forces your body to adapt but it also requires sufficient nutrition, rest and sleep for those adaptations to occur.
An individual weak session is not necessarily a problem, there are all sorts of reasons why you might perform badly for one session. But if it continues for multiple sessions, that is a sign that something isn't right in your recovery. If you don't change things, a sustained plateau and/or injury is likely.
Most people schedule a lighter week in to their training plans after every 3 or 4 weeks.
Other things to consider:
- Are you getting enough good quality sleep?
- Are you fuelling enough before and after training sessions? Are you eating enough protein and getting a balanced diet?
- Have you had a recent increase in volume or intensity of any of your training?
- Any external stressors? Additional stress? Working longer hours than usual? Kids stopping you sleeping? Is your body tired from other sports like running or cycling?