The intensity trap lies in waiting for those who are short on training time. It lies in wait for those who want to suffer the most. It lies in wait for those who want to be faster, fitter, better in a hurry. It lies in wait for those who want to over-achieve. It is in fact possible to do both your easy aerobic endurance sessions and your hard aerobic sessions too hard!
Let me explain; In all sporting events lasting more than a few minutes, energy provided by the aerobic system that dominates. The anaerobic or glycolytic component, whilst necessary, plays a much smaller role. This is especially the case in time trial based events where fewer tactics are involved and results rely upon you getting the best out of yourself. However, a paradox lies in the fact that aerobic improvements can take many months or years to come to fruition while anaerobic improvements take only a handful of weeks. When this fact is allied with current health and fitness trends (towards HIIT training), and we add into the mix athletes who judge training effectiveness by their degree of suffering and possibly athletes who are extremely time limited, we can begin to see how intensity can be overly utilised within a training period.
Athletes who aren’t coached in their chosen sport need to understand that aerobic development is centred around building new ‘hardware’ such as capillaries to get oxygen to the muscles and mitochondria to use the oxygen to make energy (plus many others). This process, quite simply, takes a while. Patience, consistency and faith or trust in the process are required when positive outcomes don’t come immediately.
Aerobic endurance exercise also, typically, doesn’t feel so hard; at least not until you’ve been at it for a long while. This means that you can be tempted to work harder; surely harder is better? Well not necessarily in this case. Ideally you’ll increase the time of these so-called ‘Zone 2’ sessions and not the intensity. If you’re short on time then splitting the session into 2 may help (half before work and half after) and/or you may wish to exercise near to the top of zone 2 (heart rate, pace, power). Although its ideal to complete progressively longer endurance sessions it’s likely that weekly or monthly volume is as if not more important. This means that if you dont have time for a 3hr ride on Sunday but can manage 90mins and then make up those missing 90mins through the reminder of the week then this is still highly likely to lead to improvements.
For those upper aerobic sessions (threshold or VO2max intensities), it also possible to go too hard. Experience is crucial to execute these sessions well. If you fail mid-way through then you went too hard on that given day. Goal number 1 is to complete the session or desired number of reps at approximately the right effort level (this can be based on RPE, power, pace or HR). These sessions will utilise a significant proportion of anaerobic energy but the over-arching goal is to develop aerobically and so my advice is to start a little cautiously and build in to the reps and the session as a whole. Keep repetition length on the longer side (e.g. threshold at 7-10mins, Vo2 max at 3-6mins) and quite crucially keep the recovery period quite short (2-4 mins works for almost all workouts). The short recovery prevents the anaerobic energy system from ‘recharging’ fully; meaning that the effort produced has to come more from aerobic means.
So, to avoid the intensity trap, consider that while anaerobic improvements often come about more quickly, they can in fact hinder longer term progression, which is through the greater capacity of the aerobic system to grow and improve. Employ INTENSITY DISCIPLINE – meaning keep within the desired rep ranges and effort levels to ensure that you are getting fitter year after year. Trust the process!