Mercury 3: 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: 60 of 100
Analysis rating: 752
Head to head, this task: won 9 of 12

Why it is not sound

The survey

Answer bands that overlap or leave gaps

The analysis

Reported a material finding the data does not support
Made a recommendation that does not follow from the data
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: 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.
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.

Findings the judges found unsupported

24-hour access is a core brand attribute for the overnight segment: 59.2% of overnight visitors chose Corefit because it was open 24 hours, versus 24.0% of all members. Sixteen open-text respondents, almost all night-shift or other workers, said 11pm-5am is the only time they can train.The 24.0% choosing 24-hour opening is a percentage of unweighted respondents, not an established percentage of all members. Overnight users, who select this reason much more often, are over-represented.
Overall cancellation intention is relatively low, but it is heavily concentrated among overnight users: 14.6% of all respondents said fairly/very likely to cancel, versus 45.8% of overnight visitors and 9.2% of non-visitors. Using the 6% door-entry share gives a weighted cancellation estimate of 11.4%, about 4,400 members.It turns the weighted 11.4% stated likelihood of cancelling into a 'cancellation estimate' of about 4,400 members. That treats a hypothetical, prompted intention as a forecast of actual cancellations, which the data does not support.

Scorecard

Numbers 11 of 11 right

Question		Its answer	True
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?	✓	4,400	4,383
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').	✓	2	2
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 points	2.27 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)	✓	No	No
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?	✓	16	16
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?	✓	19	19
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

Findings

Around 15% of respondents said they used a Corefit gym between 11pm and 5am at least once in the previous four weeks (14.9% ±2.3pp at 95% confidence). This is higher than the 6% door-entry record for September, so it is best treated as an upper bound of self-reported overnight use, not the population figure.

High confidenceBase 950

Q1, base 950; door-entry: 6% of 38,600 = about 2,316 members.
Overall cancellation intention is relatively low, but it is heavily concentrated among overnight users: 14.6% of all respondents said fairly/very likely to cancel, versus 45.8% of overnight visitors and 9.2% of non-visitors. Using the 6% door-entry share gives a weighted cancellation estimate of 11.4%, about 4,400 members.

Medium confidenceBase 950

Q4: 142 overnight users, 808 non-users; population 38,600.
24-hour access is a core brand attribute for the overnight segment: 59.2% of overnight visitors chose Corefit because it was open 24 hours, versus 24.0% of all members. Sixteen open-text respondents, almost all night-shift or other workers, said 11pm-5am is the only time they can train.

Medium confidenceBase 142

Q5; open-text IDs M162, M166, M222, M300, M321, M492, M551, M568, M592, M593, M685, M695, M752, M793, M889, M924.
Closing overnight would affect more than current overnight users. Many off-peak users would lose the quiet they value; 31 open-text respondents predicted crowding in the 10-11pm or 5-6am windows if overnight users were displaced.

Medium confidenceBase 31

Open-text answers coded to crowding theme; examples include M057, M058, M152, M177, M190, M208, M264, M324, M361, M445, M454, M509, M529, M533, M557, M588, M699, M734, M739, M804, M812, M832, M849, M900, M918.
The North West/North East regional gap in cancellation intention (19.2% vs 13.6%) is not statistically significant at the 95% level (z≈1.61, p≈0.11). It does not support a regional 24-hour policy based on this survey.

High confidenceBase 449

Q4, North West base 229; North East base 220.

Open-text themes it coded

No direct effect / unaffected 90Expect lower price or discount if hours are reduced 9

The survey it planned

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

S1
Are you currently a Corefit member?
One answer
- Yes
- No
Continues if Yes
Q0
Which Corefit gym is your home gym? (Select from the list below.)
One answer
- Gym 1
- Gym 2
- Gym 3
- Gym 4
- Gym 5
- Gym 6
- Gym 7
- Gym 8
- Gym 9
- Gym 10
- Gym 11
- Gym 12
- Gym 13
- Gym 14
Q1
Which of the following were reasons you chose Corefit? Please select all that apply.
Any that apply
- It is open 24 hours
- It offers a rolling monthly membership (no long contract)
- The price / value for money
- The location / convenience
- The equipment / facilities
- The atmosphere / staff
- It was recommended to me
- Other
Q2
In September 2026, how many times did you enter a Corefit gym between 11pm and 5am?
One answer
- None
- Once
- 2-3 times
- 4-6 times
- 7-12 times
- More than 12 times
Q3
When you visited overnight, which time slot did you usually enter the gym?
One answer
- 11pm-12am
- 12am-1am
- 1am-2am
- 2am-3am
- 3am-4am
- 4am-5am
- No usual time
Routing Shown only if Q2 is: Once; 2-3 times; 4-6 times; 7-12 times; More than 12 times
Q4
If your home Corefit gym were closed between 11pm and 5am, how likely would you be to cancel your Corefit membership?
Scale

Scale 1-5: Very unlikely to Very likely
Q5
If your home Corefit gym were closed between 11pm and 5am, what would you do? Please select all that apply.
Any that apply
- It would not affect me
- I would use the gym at other times
- I would use another Corefit gym that remains open
- I would use a different (non-Corefit) 24-hour gym
- I would cancel my Corefit membership
- Other
Q6
How long have you been a member of Corefit?
One answer
- Less than 3 months
- 3-6 months
- 6-12 months
- 1-2 years
- More than 2 years
Q7
What is your age group?
One answer
- 18-24
- 25-34
- 35-44
- 45-54
- 55-64
- 65+
Q8
Which best describes your usual weekly schedule?
One answer
- Standard daytime hours
- Shift work / irregular hours
- Student
- Retired
- Looking after family/home
- Other
Q9
How important is it to you that Corefit gyms are open 24 hours?
Scale

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

Sample plan

Invite a random sample of current members from the Corefit membership database, stratified by home gym, using the email addresses on file. Target approximately 1,000 completed surveys. Set a quota of at least 70 completed surveys per home gym (about 980 in total) and allocate the remaining ~20 completions to the largest gyms; any gym with fewer than 70 members will be censused. Weights will be applied to adjust for non-response and oversampling. Important caveat: the requested +/-8 percentage-point margin at 95% confidence for all 14 gyms would require about 150 completes per gym (~2,100 total). With 1,000 completes, gym-level margins will be wider (roughly +/-12 points for 50% responses and about +/-6 points around the expected 6% overnight-use rate). If the +/-8 requirement is fixed, the completion target must be raised to ~2,100.