What 31,812 Marketing Emails Reveal About Why Your Gym Newsletter Gets Ignored

Apple’s iPad Pro launch email arrived in millions of inboxes with the subject line The new iPad Pro. Supercharged by the Apple M1 chip. Forty-eight characters of product description, with no exclamation point and nothing in capitals.

The weekly newsletter from a typical chain gym reads more like FLASH SALE: 50% OFF MEMBERSHIP!!! ENDS TONIGHT. Every email marketing course teaches a gym owner to write that way. The gym version should win.

A study published in Ampersand this year, run on 31,812 real marketing subject lines and 4.6 billion sends, says it does not. The “power words” gym owners are told to lean on cost the email opens by 3.5%, and ALL CAPS costs another 3.3%. Apple’s plain copy is, on the data, the version that gets opened more often.

What the research found

McVeigh and Liimatta analysed 31,812 email subject lines pulled from the marketing company Alchemy Worx, sent a combined 4.6 billion times, with an average open rate of 17.6%. Each subject line was coded for parts of speech, capitalisation, personalisation, and use of “power words” (the industry term for vocabulary like FREE, NOW, and FLASH). A mixed-effects regression then mapped each feature against the open rate.

Subject lines using power words had open rates 3.5% lower than equivalent subject lines without them, and ALL CAPS reduced opens by another 3.3%. A noun-and-verb-heavy “sale-driver” construction, the structure at the heart of most discount-led emails, cost a further 1.8%. Features that increased opens included a single exclamation point at 3.9%, personalisation at 1.6%, and slightly non-standard writing such as lowercase openers and unusual spacing, also at 3.9%. The pattern in the data favoured plain, mildly personal copy over the standard shouty version.

Why this happens in your gym

A gym subscriber who joined the mailing list six months ago has, by now, seen dozens of marketing emails from competing gyms. They have built the same mental model of “gym marketing email” that they have built for every other product category. The model is loud and pricing-led.

When the subscriber’s inbox refreshes on a Wednesday morning, the brain runs a fast pattern match against the model. Anything that scores high against the model gets routed past attention before it is consciously seen. The subscriber doesn’t think “I will ignore this gym’s email”; the email never registers as an item to be opened.

Apple’s subject lines do not match the gym-marketing model at all. They read as product information, which the brain routes to a different folder, and the email gets opened.

The chain gym sending FLASH SALE: 50% OFF MEMBERSHIP!!! is, by the data, training its own list to ignore it. Each louder subject line sharpens the recognition pattern in the subscriber’s head, and the next email gets skipped more reliably. When opens drop, most gym owners reach for louder copy. The data says that move makes the trend continue.

Where this goes wrong

McVeigh and Liimatta’s corpus mixes retail, travel, and software, and the gym vertical is not broken out separately. The size of the negative effect on open rates is small per feature, around 3% relative; on a list of 5,000, that is roughly thirty fewer opens per send when one feature is present, and the penalties stack when several are. Whether that scales to a measurable revenue effect depends on how much of the gym’s lead pipeline is actually email-driven.

Plain copy doesn’t always work. Cutting the marketing tells can also cut whatever reason the subscriber had to open the email. Apple gets away with The new iPad Pro because the brand carries the email; the subscriber already wants to know what Apple just announced. A regional gym sending The new winter timetable to a cold list has stripped the marketing language without supplying anything to replace it. Plain copy works only when something else in the subject line earns the open.

Readers who don’t open ALL CAPS subject lines also tend to sense, accurately, that they are on a marketing list rather than in any working relationship with the business. Over time this shows up as a dead list. A gym whose subject lines are mostly discount-led is training its readers to treat it as a faceless promotional channel. When that gym eventually needs the list to do something specific, like book a trial or attend an event, the response rate reflects the years of training.

The Question

If your gym’s next subject line had to read like one friend writing to another, with no marketing department behind it, what would it say?

People Also Ask

What are “power words” in gym email marketing?

Power words are an industry term for emotionally charged or urgency-loaded vocabulary that email marketing guides claim will improve open rates. Common examples include FREE, NOW, and FLASH. They are part of a broader toolkit of persuasive copywriting techniques built around cognitive biases. The McVeigh and Liimatta study (Ampersand, 2026) tested 680 such words across 31,812 subject lines and found that subject lines using power words had open rates 3.5% lower than equivalent subject lines without them. Readers have learned what marketing language looks like and treat its presence as a signal to skip the email.

Do ALL CAPS subject lines hurt gym email open rates?

On the available evidence, yes. The same study analysed 31,812 marketing emails and found that subject lines containing ALL CAPS words or phrases had open rates 3.3% lower than subject lines without them. The effect held even though ALL CAPS is one of the only emphasis tools available in a subject line, since italics and bold are not supported. Earlier research on personal and professional email had already documented the same negative perception, and the new findings extend it into commercial messaging.

Why do gym newsletters get ignored?

Pattern recognition is the dominant factor. Subscribers see hundreds of marketing emails before yours arrives, and they build a mental shortcut for what “a gym discount email” looks like: ALL CAPS, exclamation points, urgency words. When a new email matches that pattern, it gets passed over before the subscriber has consciously read it. Adding more urgency, the standard fix when opens drop, tightens the pattern and makes the skip happen faster. Subject lines that read more like product news than sales copy tend to break the pattern and earn the open.

Closing

Most gym owners write for an audience that taught itself to filter them years ago.

If you want a behavioural-science walkthrough of your gym’s next email campaign before you send it, book a free 30-minute chat.

References: McVeigh, J. & Liimatta, A. (2026), ‘Do You Want $150 for FREE? Measuring the effect of language on marketing email open rates’ (Ampersand). Friestad, M. & Wright, P. (1994), ‘The Persuasion Knowledge Model of Persuasion’ (Journal of Consumer Research).