Volume and intensity are the two most important variables in triathlon training. Volume is how many hours/distance you cover across swim, bike and run and Intensity is how hard you do these things.

In triathlon training, the most effective way to gain fitness is by doing approximately 80% of your weekly volume at low intensity and 20% at a high intensity. We will define these variables a little later on. This 80/20 rule will give you a framework to plan and execute your training.

So your overall training load (a combination of the volume and intensity) will be pretty large at times. And as a result of this you may feel tired. Factoring in rest and/or easy days in-between harder sessions will help you gain fitness. If you train at a high intensity across multiple days and don’t allow enough recovery, you will quickly find that you are extremely fatigued, unable to hit numbers and often susceptible to picking up niggles or illnesses.

Triathlon being a multi sport event can get quite confusing about how to best split your time between the 3. A good rule for training distribution is splitting into 3 unequal parts depending on how long each section may take in a race. For example, if an Olympic distance triathlon takes 2 hours and is split into 1/4 on the swim, 1/2 on the bike and 1/4 on the run it makes the most sense to train in that distribution across the 3. Basically you would train 2x as long on the bike as you would for swim and run.

Volume is the combination of frequency and duration of your training. By adding up how many hours a week of training you do, you get volume. Across this weekly volume there will be varying degrees of intensity within the plan and its those parts that will help push up your fitness the most.

Let's say you have 12 hours a week you can train for swim, bike and run. You wouldn’t want to spend 4 hours doing each because each triathlon leg isn’t proportional. We would recommend you spend 6 hours on the bike and 3 hours each swim and run. This way you have a far more balanced programme that will address weakness and build volume across all 3 sports.

Pace, heart rate, power and perceived effort are all ways we can monitor the intensity of sessions. Being able to assign a level of intensity to a workout with a numeric scale is a great tool to use across all 3 sports. As an example the 80% of your training should be done RPE 1-4 and your Intensity should be split between 5-8 (15%) and 9-10 (5%) depending on what sessions you have within your training programme.

Even though there are more ‘accurate’ ways to measure intensity like Heart Rate and Power, if you don't have access to those markers, using a RPE chart is still a very useful tool and one that the pros always come back to too!

Trying to spin all three plates and be the fittest as possible across each discipline is tough. It is tempting to spend more time on your favourite discipline but to get the best out of yourself on race day, you want to train all three sports as best as you can. As a general rule or if you are new to triathlon, we recommend spending 50% of your total weekly training on the bike; the largest of the three disciplines and the one that will give you more bang for your buck. The remaining 50% should be split between swim and run training.

If we look at the approximate time it takes to complete each discipline in an Olympic triathlon, then we can see why being fit and strong on the bike is the most valuable. An elite level triathlete would complete the swim in ~25 min, bike ~60 min and run the 10k in ~35 min run. The bike portion takes ~2x longer than the run and swim, so it makes sense to train that for longer. Don’t forget that you will also gain lots of aerobic fitness on the bike or in the pool that can translate into your running.

This is a general rule for starting out, but if you have more experience and know your strengths and weaknesses then it is worth spending more time on your weaker sport. For example, Coach Beth (an International Triathlete & World Champion) started triathlon after a career in Track and Field running and swam as a junior. Beth had limited history of any specific bike training but her running and swimming was strong. To bring her biking up to the same standard, Beth spends 65% of her training on the bike with 25% on swimming and 10% on running. This is something to consider when you are planning your training. Not one rule fits all but you can identify what areas need work and spend more of your training hours on this sport.

Good luck!