How long should my workout be?

How long should your workout be?

Often personal training sessions are sold in terms of time. 30/45/60minutes. When we look at why, there appear to be issues arising around value, perception and misunderstandings of some key literature.

Research has shown that favourable hormonal changes due to resistance exercise typically take around 20 minutes to occur, peaking at around 45 minutes and dropping after 60 minutes (Zatziorsky & Kraemer, 2006). The key words in that last sentence are ‘favourable’ and ‘typically’.
Testosterone and growth hormone are increased during resistance training and even during high intensity interval training. These help promote muscle growth and recovery and stand to increase fat metabolism – though the research is cloudy even on this (Ronnestad et al., 2011; West & Phillips, 2011). Testosterone is also linked to strength increases making it logical that once this starts dropping, along with fatigue, strength may be reduced.

So on the surface is seems like the best training duration is 45-60 minutes. Enough time to peak the right hormones and burn enough calories to make it worthwhile. Right? As always the answer isn’t quite so simple.

Many people are training for events that will last over an hour, as such they will need to do some training – not all – for longer periods to create the kinds of conditions that their bodies will need to be ready for. Other people train for events that last only a few minutes or less meaning their training will need to be quite different. ‘Typically’ makes the assumption that everyone will respond the same, and that all exercise and training has the same effect. They don’t and it doesn’t.

Favourable changes in growth hormone and testosterone are beneficial no matter the sport or the person. Natural exercise induced levels have a positive impact on both strength and fat loss. However, just because they peak at X and drop after Y is in my opinion a relatively poor reason to design a session based on minutes. After all your body may peak at X + 5 and drop after Y + 10.

Instead, consider that each training session must have an aim. Performance based ideally. If the aim of your programme is to stimulate muscle growth in a certain area, both the duration and exercise prescription should reflect this. If that occurs after 47 minutes, great, go get your protein shake and have a shower. If your goal is to complete 10 sets of 4 front squats because that’s what it’ll take to make you strong enough to increase your track cycling performance, it could take 35 minutes. Great, go get your shake and have a shower. If your cycling coach knows that if you complete 5 rounds of uphill high power sprints at the right intensity you won’t complete a 6th. You’re done, cool down and grab a shake. A weightlifter with 8 x 3 cleans, 4 working sets of back squats and some assistance work might be in the gym for 1.5 hours. Thirty minutes of that is probably rest periods, at least 15 minutes was warming up and stretching. Goals are set, met and they go home.

In my opinion each session should be based around a goal (or two) and once met, you’re done. If you hit each progressive goal in sequence and you’re nutrition is good you’ll see results. In personal training too often, clients diets are not good, sleep is inadequate, stress is high and they turn up late. The resulting session is spent on damage limitation. In this less than perfect scenario, trainers are left with the decision to either stick with the plan – knowing it is compromised and goals probably won’t be met – or to go off piste and work based on creating as much metabolic cost as possible to offset the poor diet. Other times the athlete or client is so knackered after 35 minutes that anything other than stretching would be poor quality and ineffective.

Is there a solution? Like with any good plan, there should be a plan B. My plan B is knowing what parts of the session are essential and what can get cut if time or circumstance prevents it. Knowing a minimal dose response is paramount – what is the least I can do to get the effect I want? When you know this, you know how long you need to achieve it. Sometimes (like with the squat) you have to do other things before you can even begin to do the primary exercise. Mobility and flexibility drills take time too, it all has to be accounted for.

The question becomes “What are you selling/buying?” If you sell hours or minutes then it is your obligation to provide and fill those minutes. If you are selling results, goals, performance enhancement and skills then you have no obligation to fill minutes just because it’s easier to work on an hourly schedule. A session is over when the prescribed work is done. If, as the athlete or client you question the content or quality of the work given, question it. There should be enough of a rapport and keenness to teach/learn that this is not seen as threatening. Personally I want my clients to understand why some sessions are exhausting and some not, why some last 40 minutes and others 65. If I tell them they are done at 45 minutes and that they can stay and stretch but do no more exercise thats what they do.

Training is about creating progressive physiological and psychological adaptations and learning skills or movement patterns, not about filling an arbitrary amount of time because you have a gap in your schedule.

By Alex Adams