How to train aerobically

Why you are training

How you should train depends on what you want to get out of it.

1. Beginner - start gently

Whatever your long-term goal is, it is best to start with very easy sessions, ones where your heart rate stays below 50-55% of maximum. That is training where your breathing is only slightly faster than normal.

Easy training like this gives you several things:

A body that is not used to sustained effort gets to wake up gradually. It has time to adapt without sudden shocks.
Your muscles, tendons and joints are not loaded heavily, so the risk of injury is far lower. They still start getting stronger from the very first session, building a solid base for everything that comes later.
Even gentle training pays off in better mood and more energy. And because it is gentle, it does not wear you down or put you off, so you have time to settle into the new routine.

Only once you have been training for a while, and holding a steady 30-minute session is no trouble, is it worth deciding what you want to work towards next.

2. Health and vitality - work up to your ceiling

Aerobic training raises your general fitness, improves circulation, gets more oxygen into you and leaves you with more energy. If that is your main goal - reaching new levels of fitness and strengthening your cardiovascular system - you will have to raise the intensity of your sessions gradually.

Once you can hold 30-40 minutes of steady work, you can start making it harder.

Build up slowly and spread it over time. Each week, try to fit a little more into the same 40 minutes - a few more repetitions, a few hundred metres more. Keep the steps small: change the intensity too much and you will not last the full 40 minutes.

The ceiling worth aiming for differs from person to person. It is usually given as 80-85% of maximum heart rate, but treat that as a rough guide - the standard formulas are estimates, and real maximum heart rates vary by more than ten beats either side of what they predict. The more reliable check is the talk test: try speaking while you train.

If you can hold a normal conversation, you are not training at the top of your capacity.
When talking makes you run out of breath almost immediately, the session is as intense as it should get.
If you are gasping even without talking, the session is too intense: too little oxygen is reaching your muscles and they are switching to anaerobic energy production.

3. Losing weight - easy and long

Wanting to lose excess body fat is one of the most common reasons people take up aerobic training.

Your body burns fat and carbohydrate side by side from the very first minute - there is no switch that flips after a set time. What changes the mix is intensity: the easier the session, the larger the share of fat. And what actually decides whether you lose fat is the total energy you spend over weeks, set against what you eat.

Training for weight loss should therefore be easy. Work with your breathing only slightly faster than normal, nowhere near the limit of your capacity - at that intensity you burn a high proportion of fat and, more importantly, you can keep going.
And it should be long. A longer session simply burns more energy, so aim for 40-60 minutes, up to 90 as your fitness allows. The point of the extra time is the extra energy spent, not some threshold you have to cross.

Twice a week at least, three times ideally

The best frequency for aerobic training is every other day.

One day of training
One day of recovery

Your body gets time to rest, and the benefit of the last session has not worn off by the time you start the next one.

The minimum is twice a week. Train less often than that and you will not raise your fitness by much - every week feels like starting over.

Every day is possible, but carefully

Daily aerobic training is possible, but it has to be done with care.

Be very careful not to overtrain and injure yourself. If any muscle - and above all any tendon or joint - starts hurting, take a break and let it recover. Ignoring those signals is how injuries happen.
If you feel your body is worn out, with less energy rather than more, rest.
Alternate disciplines from day to day, running and swimming for instance, so the work is spread across different muscles and yesterday's are left to recover.

Only move to daily aerobic training once you have trained every other day for many months and feel no fatigue or other side effects. Training every day from day one is the most common mistake there is. Daily training belongs to advanced athletes with high endurance and a body that recovers fast.