There's something strangely satisfying about finishing a workout feeling completely spent, right?

When you get the feeling you just know you’re gonna be sore tomorrow.

Many people see these feelings as signs of a good workout. On the flipside, if you finish your session feeling pretty fresh or wake up the next day feeling good with little soreness, you’re probably left wondering if you’d done enough.

This raises an interesting question though:

What do short-term feelings of fatigue or muscle soreness actually tell us about the long-term benefits of exercise?

Let’s see what the evidence says - and what it might mean for building a consistent and sustainable exercise routine.

Is muscle soreness a sign of progress?

Most people are familiar with the uncomfortable sensation of muscle soreness after exercise.

This is known as delayed onset muscle soreness (or DOMS), which usually peaks in the 24 to 72 hours after exercise. It’s most prominent when you do exercise or movement you’re not accustomed to, particularly when it focuses on eccentric muscle actions (the kind you do when lowering a weight).

While DOMS is familiar to most people, it’s also highly misunderstood.

Firstly, despite common perception, it’s actually not a reliable marker of muscle damage. That means being more sore after a workout does not necessarily mean it created more muscle damage. In fact, Nosaka et al. (2002) found only weak or absent correlations between soreness and several other indicators of exercise-induced muscle damage.

Secondly, DOMS isn’t a reliable indicator of muscle adaptations either - including muscle growth. That means feeling more sore the day after a workout does not mean you’ve stimuluated your muscles to grow more. Nor does it mean your workout wasn’t effective if you don’t feel sore.

To understand this, it’s important to be aware of a phenomenon called the repeated bout effect. Essentially, the fact that repeating the same exercise over time generally produces less soreness the more we become accustomed to it.

This means you might experience considerable soreness when starting a new training program, but much less as the weeks go by - even though you’re continuing to get stronger and build muscle.

As an example, a 1995 study in men aged 50 to 69 years found 16 weeks of training led to decent gains in their strength (+43%) and muscle size (+7.2%), despite levels of muscle soreness being only occasionally reported early in the program, and almost never towards the end.

The point is, you can still benefit from exercise when it doesn't make you sore.

But does more fatigue mean more benefit?

First, let’d distinguish fatigue from soreness.

Fatigue is usually defined as an immediate or lingering (but reversible) decrease in physical capacity, such as strength levels. On the contrary, soreness usually emerges later, but can also interfere with physical performance.

It’s probably obvious to most people that training with more intensity, or more volume, will cause more fatigue. The question is whether maximising fatigue leads to maximising adaptation.

Looking at the research on this, there are probably a few ways this question could be answered. On one hand, training with higher intensities and/or volumes, which may be associated with more fatigue, might be expected to result in more fitness gains - at least in the short term.

But another way of looking at this is whether maximising the fatigue associated with a given dose of training provides more benefit.

To try to answer this, a 2002 study had young healthy adults (aged 18-29) did the same volume of resistance training, with the same relative load (weight), in either a high fatigue or low fatigue manner:

• High fatigue: Four sets of 10 reps with 30 seconds between sets
• Low fatigue: 40 reps with 30 seconds between each rep

So both groups did the same total dose (reps and relative load lifted), but the recovery between each repetition was modified to influence fatigue.

The punchline was that after nine weeks, both groups improved their strength considerably. Although gains were numerically greater in the high-fatigue group (+18.2% vs. +14.5%), the difference wasn’t statistically significant.

While this doesn’t prove both approaches are equally effective, it does show that substantial strength gains can occur without deliberately maximising fatigue.

The problem with chasing soreness or fatigue

Many people seem to be preoccupied with making sure they finish a workout exhausted or sore.

And I get it - most people probably want to make sure their session is “worth it”, or chase quick results. Or perhaps just get the session over with as quick as possible.

But aside from soreness or exhaustion not being mandatory for benefiting from exercise, there are some important downsides too.

First, if you’re more tired and sore after a workout, this increases the recovery demands and has a flow-on effect for your next session - maybe you can’t do what you planned, or worse, you skip the session altogether.

Secondly, deliberately chasing fatigue or soreness can mean making workouts unnecessarily demanding or uncomfortable, whether that’s through more repetitions, shorter rest periods, or simply pushing yourself harder.

And that matters - because it can affect if we want to do it again.

It turns out how we feel during exercise - what researchers call our affective response - can help predict our future physical activity levels. Generally, people who feel better during exercise tend to be more active in the future. That’s not to say challenging exercise is always unpleasant, but rather there is value in considering how we experience exercise, instead of just how much effort we put in.

It’s yet another reason to think beyond the demands of any single workout, to what will help keep you exercising over the long term.

What you should judge your workouts on instead

This is where a little perspective is helpful.

If you zoom out, you begin to shift your attention from trying to squeeze as much juice as possible out of every session, to things like:

Are you gradually getting a little stronger, fitter, healthier, or more physically capable over time?

Is your exercise challenging enough to support your goals, without pushing the limit every time?

Do you find you recover enough between sessions to perform your next planned session?

And is your approach realistic and enjoyable enough to keep you coming back?

Remember, not every training session has to induce measurable progress. Sometimes they will, but others might be more about just maintaining your fitness, or even just keeping your routine and habit in check.

That’s why a “good” workout doesn’t have to leave you sore and exhausted - it just has to be enough to support your goals, allow you to recover, and ultimately - make you want to do it again next time.

I hope this was helpful!

Until next week,

Jackson

​​​

If you've got a moment, I'd love to hear your thoughts on this edition of The Weekly Exerciser.

Send me a quick message or email - I'll reply to every one!

PS: Did someone forward you this email? You can sign up to The Weekly Exerciser here.

IMPORTANT:

The information contained herein is of general nature only and does not constitute personal advice. You should not act on any information without considering your personal needs, circumstances, and objectives. Any exercise program may result in injury. We recommend you obtain advice specific to your circumstances from an appropriate health professional before starting any exercise program.