The best protocol to follow is to do the assessments just before exercise, or for sake of consistency, always in the morning. If possible, avoid having caffeine-based drinks or other stimulants before the measurement.
Also try not eat heavy meals before the assessment. If conducted in the morning, please give yourself some time to fully wake up. Despite our recommendations, do the assessment whenever it fits into your daily schedule the best. Only try to consider what variables may be affecting your measurement at any given time.