Benchmarks / SurveyBench / Should Corefit gyms stop opening 24 hours? / Mistral Large 4

Measured by Spring Prompt

Mistral Large 4: Should Corefit gyms stop opening 24 hours?

The decision: whether to close all 14 gyms between 11pm and 5am, close overnight only at the quietest gyms, or keep every gym open 24 hours. The brief and the data →

Verdict
✗ Not sound
Research score
78 of 100
Analysis rating
815
Head to head, this task
won 8 of 15

Why it is not sound

The survey

  • Ignored the precision the brief asked for, which the sample cannot deliver

The analysis

  • Reported a material finding the data does not support
  • Missed a trap: 'Likely to cancel' answers (45.8% of overnight users, 14.6% overall) are stated intentions about a hypothetical closure, asked straight after members were invited to think about it.
  • Missed a trap: At Wakefield Calder Park (base 11), 54.5% of respondents used the gym overnight and 27.3% say they would be likely to cancel.
  • Missed a trap: Only current members were surveyed: people who joined for 24-hour access and have since left, and people who would join only because of it, are missing, so the survey cannot show what 24-hour opening does for recruitment or the brand; and night-shift workers are a small group whose answers carry little weight in the totals even though they depend on the hours.
  • Proposed a mistaken next step: Decide the hours at Wakefield Calder Park (or across the chain) from its survey result alone

Findings the judges found unsupported

  • Overnight usage is concentrated among night-shift workers. While only 14.9% of all members report using the gym between 11pm and 5am, this rises to 80.4% of members working shifts that include nights. The median overnight user visits 2-3 times in four weeks (mean 7.4), indicating a small but heavily engaged segment.14.9% describes survey respondents, not all members. Door-entry records put population overnight use at 6%. The caveats acknowledge this, but the finding still mislabels the survey estimate.
  • Closure would trigger disproportionate churn among overnight users. 45.8% of overnight users say they are likely (4-5) to cancel versus 9.2% of non-users. Weighted to the population (6% overnight users per door-entry data), this projects to approximately 11.4% of all members (~4,399 of 38,600) likely to cancel.The weighted calculation of approximately 11.4% is supported as stated cancellation intention, but 'would trigger' churn and the subsequent projected loss of about 4,400 members turn hypothetical intentions into an actual cancellation forecast. The caveat does not resolve this contradiction.
  • Price fairness is a major barrier to acceptance. 43 respondents (18% of open-text answers) explicitly state they would expect a lower monthly fee if hours were reduced, even if they never use the gym overnight. Unaddressed pricing concerns could amplify churn beyond stated likelihood.The supplied answers contain 52 explicit fee-reduction expectations, not 43. The analysis also inconsistently reports 42 in its theme summary. Price fairness is supported, but its reported frequency is not.
  • Safety concerns about unstaffed overnight hours are widespread. 36 respondents (15%) spontaneously cite feeling unsafe, uneasy, or vulnerable with no staff present overnight, suggesting closure could improve satisfaction for some members and mitigate reputational and liability risk.The supplied answers contain 41 safety-related responses, not 36. They support perceived unease and some positive reactions to closure, but do not establish that closure would reduce actual liability or reputational risk.
  • Displacement risk is material for early-morning and late-evening users. 30 respondents who train at 5am or around 10pm fear that closing overnight will funnel displaced users into their preferred quiet slots, degrading their experience and potentially driving secondary churn among non-overnight users.The supplied answers contain 32 crowding or loss-of-quiet responses, not 30. These establish concerns about displacement, not observed displacement or secondary cancellations.
  • Wakefield Calder Park is an extreme outlier. With a small base (n=11), 54.5% report overnight use and 27.3% say they would likely cancel—far above any other site. This gym must retain 24-hour opening or face disproportionate losses.Wakefield's percentages represent six overnight users and three likely-to-cancel respondents out of only 11. They cannot establish that this gym must remain open overnight or would suffer disproportionate actual losses. Calling confidence low does not justify the categorical decision.

Scorecard

Numbers 11 of 11 right

QuestionIts answerTrue
What percentage of respondents reported at least one visit to a Corefit gym between 11pm and 5am in the last four weeks?✓14.9%14.9%
What percentage of all respondents said they would be likely (fairly or very) to cancel their membership if their home gym closed between 11pm and 5am?✓14.6%14.6%
Among respondents who reported at least one visit between 11pm and 5am in the last four weeks, what percentage said they would be likely (fairly or very) to cancel?✓45.8%45.8%
Weighted so that respondents with at least one visit between 11pm and 5am in the last four weeks count as 6% of members (the door-entry figure) and the rest as 94%, what percentage would be likely (fairly or very) to cancel?✓11.4%11.4%
If the weighted share likely to cancel were applied to all 38,600 members, about how many members would that be?✓4,3994,383
Among respondents who reported at least one visit between 11pm and 5am in the last four weeks, in which band of the Q1 table does the median number of visits fall? Give the lowest value of that band (for example 4 for '4 to 7').✓22
What is the 95% margin of error, in percentage points, on the unweighted share of respondents who reported at least one visit between 11pm and 5am in the last four weeks?✓2.3 points2.27 points
Is the difference between North West England and North East England respondents in the share likely (fairly or very) to cancel statistically significant at the 95% level? (1 for yes, 0 for no)✓NoNo
How many of the open-text answers say that 11pm to 5am is the only time the respondent can train because they work shifts or nights?✓1516
How many of the open-text answers from respondents who visited between 11pm and 5am in the last four weeks say they would move to another gym?✓1919
What percentage of the members invited completed the survey?✓8%8%

Traps in the data 5 of 8 handled

  • ✓14.9% of respondents report at least one visit between 11pm and 5am in the last four weeks, against 6% of members in the door-entry records: members with a stake in the overnight hours were more likely to respond. Unweighted, 14.6% say they would be likely to cancel; weighted to the 6%, 11.4%.
  • ✗'Likely to cancel' answers (45.8% of overnight users, 14.6% overall) are stated intentions about a hypothetical closure, asked straight after members were invited to think about it.
  • ✓The mean number of overnight visits among overnight users (7.4) is pulled up by night-shift workers who come almost daily; the median is in the '2 to 3' band.
  • ✓The operations director believes almost nobody uses the gyms overnight. Partly true: 6% of members in the door-entry records (about 2,316 people). But night-shift workers (5.9% of respondents) mostly train between 11pm and 5am (77.8% of those who visited overnight usually arrive then) and are the most likely to say they would cancel.
  • ✗At Wakefield Calder Park (base 11), 54.5% of respondents used the gym overnight and 27.3% say they would be likely to cancel.
  • ✓North West England respondents (base 229) look more likely to cancel than North East England respondents (base 220): 19.2% against 13.6%, a gap that is not statistically significant at 95%.
  • ✓Only 950 of 11,900 invited members completed (about 8%); those who responded differ from those who did not, as the overnight-use skew shows.
  • ✗Only current members were surveyed: people who joined for 24-hour access and have since left, and people who would join only because of it, are missing, so the survey cannot show what 24-hour opening does for recruitment or the brand; and night-shift workers are a small group whose answers carry little weight in the totals even though they depend on the hours.

The analysis

Recommendation

Do not close all 14 gyms overnight. The projected loss of approximately 4,400 members (11.4% weighted) is too high given Corefit's 24-hour brand positioning, the high concentration of valuable night-shift workers among overnight users (80.4% usage), and the 45.8% cancellation risk among this segment. Instead, adopt a targeted, evidence-led approach: (1) Retain 24-hour opening at gyms with high overnight usage and high cancellation risk (Wakefield Calder Park, Newcastle Byker, Manchester Ancoats, Glasgow Finnieston, Sheffield Attercliffe, Hull Marina). (2) Pilot overnight closure at the 2-3 quietest gyms with lowest cancellation risk (Leeds Kirkstall: 7.5% usage/8.8% cancel; Middlesbrough Centre: 9.9%/8.6%; Bradford Centre: 11.5%/6.6%) for three months with intensive churn monitoring. (3) Introduce a tiered 'Standard Hours' membership (5am-11pm) priced £3-5 lower per month to address the fairness concerns raised by 43 respondents. (4) Launch a targeted retention offer for night-shift workers before any closure, given their high likelihood of churn (48.2%). (5) Communicate safety benefits of closure (addressing 36 respondents' concerns) or enhanced safety measures if keeping 24-hour access. The regional manager's hypothesis about North West vs North East is not statistically supported; do not differentiate policy by region based on this survey alone.

What would change it

Door-entry data showing overnight usage is objectively negligible (<2% of entries) at specific sites, confirming that self-reported usage overstates demand. A successful three-month pilot at 2-3 gyms showing actual churn below 5% and significant operational savings. Revenue modelling demonstrating that the cost of losing 4,400 members exceeds the savings from overnight closure. Evidence that competitors (PureGym, Anytime Fitness, The Gym Group) are not capturing churned members (i.e., they exit the market entirely, increasing lifetime value loss). A follow-up survey with higher response rate or conjoint analysis showing that 24-hour access is not a primary driver of retention.

Findings

  1. Overnight usage is concentrated among night-shift workers. While only 14.9% of all members report using the gym between 11pm and 5am, this rises to 80.4% of members working shifts that include nights. The median overnight user visits 2-3 times in four weeks (mean 7.4), indicating a small but heavily engaged segment.

    High confidenceBase 950

    Q1 table (Net at least one visit 14.9%, base 950); Q1 by working pattern (Shifts that include nights 80.4%, base 56); Q1 note (mean 7.4 visits among 142 overnight users)

  2. Closure would trigger disproportionate churn among overnight users. 45.8% of overnight users say they are likely (4-5) to cancel versus 9.2% of non-users. Weighted to the population (6% overnight users per door-entry data), this projects to approximately 11.4% of all members (~4,399 of 38,600) likely to cancel.

    High confidenceBase 950

    Q4 table (Net likely: 45.8% of 142 overnight users; 9.2% of 808 non-users; Total 14.6%); Population weighting (6% door entry vs 14.9% survey); 38,600 member base

  3. The gap between North West England (19.2% likely to cancel) and North East England (13.6%) is not statistically significant at the 95% level (z=1.61). Regional variation should not drive a differentiated policy without further evidence.

    High confidenceBase 449

    Q4 by region (North West 19.2%, base 229; North East 13.6%, base 220); two-proportion z-test (p>0.05)

  4. Price fairness is a major barrier to acceptance. 43 respondents (18% of open-text answers) explicitly state they would expect a lower monthly fee if hours were reduced, even if they never use the gym overnight. Unaddressed pricing concerns could amplify churn beyond stated likelihood.

    Medium confidenceBase 239

    Q3 open-text answers (239 responses); 43 unique respondents mention fee reduction, discount, or lower cost

  5. Safety concerns about unstaffed overnight hours are widespread. 36 respondents (15%) spontaneously cite feeling unsafe, uneasy, or vulnerable with no staff present overnight, suggesting closure could improve satisfaction for some members and mitigate reputational and liability risk.

    Medium confidenceBase 239

    Q3 open-text answers; 36 respondents mention safety, unstaffed, uneasy, vulnerable, or no staff

  6. Displacement risk is material for early-morning and late-evening users. 30 respondents who train at 5am or around 10pm fear that closing overnight will funnel displaced users into their preferred quiet slots, degrading their experience and potentially driving secondary churn among non-overnight users.

    Medium confidenceBase 239

    Q3 open-text answers; 30 respondents mention crowding, queues, or loss of quiet at 5am/10pm if overnight closes

  7. Wakefield Calder Park is an extreme outlier. With a small base (n=11), 54.5% report overnight use and 27.3% say they would likely cancel—far above any other site. This gym must retain 24-hour opening or face disproportionate losses.

    Low confidenceBase 11

    Q1 by gym (Wakefield Calder Park 54.5% overnight use, base 11); Q4 by gym (27.3% likely to cancel, base 11)

Caveats

  • The survey captures stated intentions (Q4 'likely to cancel'), not revealed behavior. The 14.6% likely-to-cancel figure may overstate or understate actual churn; stated preference is a weak predictor of action.
  • Overnight usage is overrepresented in the survey (14.9% report a visit in the last four weeks) compared to door-entry data (6% of members entered at least once in September). The weighting corrects for this but assumes the door-entry figure is accurate and that September is representative.
  • The 8.0% response rate is low. Respondents may be more engaged, more affected by the issue, or more likely to use overnight hours than non-respondents, potentially biasing results toward higher churn estimates.
  • Site-level bases are small for some gyms (e.g., Wakefield Calder Park n=11; Shifts that include nights n=56), making site-specific decisions statistically fragile without corroborating door-entry data.
  • The open-text analysis covers only 239 respondents (25% of completes). Themes are illustrative but may not be representative of the full membership.
  • Q4 does not distinguish between members who would switch to a competitor (revenue retention elsewhere) versus leaving the gym market entirely, which have very different financial implications.
  • The survey was fielded in October 2026; seasonal variation (e.g., winter darkness driving more overnight use) may affect generalisability.

Next steps

  • researchPull door-entry data by gym and hour for the last 6 months to objectively identify sites with negligible overnight footfall (<2% of entries between 11pm-5am).
  • experimentPilot overnight closure at Leeds Kirkstall, Middlesbrough Centre, and Bradford Centre for three months, with matched control sites.
  • decisionDevelop and price a 'Standard Hours' membership tier (5am-11pm) at £3-5 less per month, and a retention offer for night-shift workers (e.g., discounted 24-hour rate or transfer option).
  • decisionConduct safety audit of unstaffed hours and implement improvements (CCTV review, emergency alarms, member check-in app) if keeping 24-hour opening, or communicate safety benefits if closing.
  • monitorMonitor competitor 24-hour gym openings in catchment areas of any gyms closed overnight, and track actual churn monthly against the 11.4% projection.

Open-text themes it coded

Safety concerns about unstaffed overnight hours (positive for closure) 36Expectation of reduced monthly fee / price fairness 42Fear of displaced overnight users crowding 5am/10pm slots 30Overnight access is essential; would cancel/switch/leave if closed 30No personal impact (never uses overnight hours) 79

The survey it planned

1 screening question and 10 questions, as the model wrote them.

  1. S1

    Are you currently a paying member of Corefit?

    One answer
    • Yes
    • No

    Continues if Yes

  2. Q1

    In the past 4 weeks, how many times have you visited a Corefit gym between 11pm and 5am?

    One answer
    • 0 times
    • 1 time
    • 2-3 times
    • 4-5 times
    • 6 or more times
  3. Q2

    What is the main reason you visit Corefit between 11pm and 5am?

    One answer
    • I work night shifts
    • I prefer training when the gym is quiet
    • It's the only time I can fit in a workout due to daytime commitments
    • I have sleep issues and exercise helps
    • The flexibility of 24-hour access suits my lifestyle

    Routing Shown only if Q1 is: 1 time; 2-3 times; 4-5 times; 6 or more times

    Judges: assumptive

    Assumes overnight users' main reason is one of the five listed. Someone with a different main reason cannot give an accurate answer.

    Assumptive because it does not provide an 'Other' option, assuming the respondent's main reason is among the ones listed.

  4. Q3

    Corefit is considering closing all gyms between 11pm and 5am. If this happened, what would you most likely do?

    One answer
    • Continue my membership exactly as now
    • Continue my membership but visit at different times
    • Cancel my membership and join a different gym
    • Cancel my membership and stop going to the gym
    • I'm not sure yet
  5. Q4

    If Corefit closed between 11pm and 5am, how would this affect your ability to achieve your fitness goals?

    Scale

    Scale 1-5: No impact at all to Prevent me from achieving my goals

    Routing Shown only if Q1 is: 1 time; 2-3 times; 4-5 times; 6 or more times

  6. Q5

    When you joined Corefit, how important was 24-hour access to you?

    Scale

    Scale 1-5: Not at all important to Extremely important

  7. Q6

    Which of the following were important reasons you chose Corefit? (Select all that apply)

    Any that apply
    • Low monthly price
    • Location near home or work
    • 24-hour opening hours
    • Quality of equipment and facilities
    • Friendly and helpful staff
    • No long-term contract
    • Group classes and timetable
    • Cleanliness and maintenance
  8. Q7

    If your home gym closed between 11pm and 5am but other Corefit gyms remained open 24 hours, would you travel to a different Corefit gym to train during those hours?

    One answer
    • Yes, I would travel to another Corefit gym
    • No, I would train at different times at my home gym
    • No, I would cancel my membership
    • Not sure

    Routing Shown only if Q1 is: 1 time; 2-3 times; 4-5 times; 6 or more times

  9. Q8

    Which age group do you belong to?

    One answer
    • 18-24
    • 25-34
    • 35-44
    • 45-54
    • 55-64
    • 65 or over
    • Prefer not to say
  10. Q9

    Which best describes your current work or study situation?

    One answer
    • Employed - standard daytime hours
    • Employed - night shifts or rotating shifts
    • Employed - flexible or irregular hours
    • Self-employed
    • Full-time student
    • Retired
    • Not currently working
    • Prefer not to say
  11. Q10

    If Corefit closed your home gym between 11pm and 5am but kept 24-hour access at some other Corefit locations, what would you do?

    One answer
    • Stay at my home gym and train during daytime hours
    • Switch my membership to a different Corefit that stays open 24 hours
    • Cancel my membership entirely
    • Not sure

    Routing Shown only if Q1 is: 1 time; 2-3 times; 4-5 times; 6 or more times

Sample plan

Stratified random sample of current Corefit members drawn from the membership database, stratified by home gym (14 strata). Target: 150 completed surveys per gym (2,100 completes total) to achieve ±8 percentage points precision at 95% confidence for each gym-level estimate. Note: This exceeds the 'about 1,000 completes' constraint; 2,100 completes are mathematically required to meet the board's precision target across all 14 gyms (n=150 per gym for p=0.5, 95% CI). Assuming a 20% email response rate, approximately 10,500 members should be invited (roughly 750 per gym). If response rates are lower than expected, increase invitations proportionally or conduct a census of smaller gyms. No quotas are applied; however, sample demographics (age, gender if available) should be monitored against database records to ensure representativeness.