Short answer: a New Year's gym resolution is won or lost in the first two weeks. Do four workouts in your first 14 days, which is two a week. In SisuLift's data, 74% of people who did at least four workouts in their first two weeks were still training in weeks 9-12. Of those who did 1-3 workouts, 24% were. The gap held from beginners to experts. The second finding matters just as much: one missed week barely hurt as long as people came back the week after, but two empty weeks in a row ended it for most. Below you get the full dataset, what habit research says and a plan that carries a January resolution into spring.
The data: 208 new users and 3,595 workouts
We pulled every user from the SisuLift database whose first gym workout logged in the app fell between 8 January and 4 July 2026, so at least 12 weeks before the analysis date. That is 208 people, who logged 3,595 workouts in their first 12 weeks. Only workouts logged in the app, live or by hand afterwards, are included. Runs synced from a watch and workout histories imported from other apps are excluded, so the first workout really is the first one in SisuLift.
To be upfront: not all 208 are new to the gym. In the onboarding chat, 24 picked beginner as their experience level, 87 intermediate, 60 advanced and 37 expert. For many, SisuLift is a fresh start after a break or a switch from another app. That is why we checked the main findings within each experience level too. Another limit: in January 2026 the app still had few users, so this group mostly started in spring and early summer, not in the January rush. We will update the numbers as the dataset grows.
A New Year's resolution is decided in the first two weeks
You know the pattern: the membership is paid, the first workout is done and it felt good. Then week two starts, work gets busy, Monday's session slides to Tuesday and Tuesday's slides to next week. The data shows this moment clearly. Of all 208 users, 64% trained in week 2, 52% in week 4, 43% in week 8 and 39% in week 12. The biggest drop came right after the first week, after that the curve flattened. When we grouped users by how many workouts they did in their first 14 days, the gap three months later was large:
Workouts in the first 14 days and staying power (n = 208)
| Workouts in 14 days | Users | Active in weeks 5-8 | Active in weeks 9-12 | Trained in 3+ of 4 weeks (weeks 9-12) |
|---|---|---|---|---|
| 1 | 50 | 12% | 10% | 8% |
| 2 | 19 | 32% | 42% | 16% |
| 3 | 16 | 44% | 44% | 19% |
| 4-5 | 38 | 66% | 55% | 42% |
| 6 or more | 85 | 88% | 82% | 62% |
| All | 208 | 57% | 53% | 38% |
- One workout in two weeks almost always meant stopping: only 10% trained in weeks 9-12. One in five of the whole group never did a second workout within 12 weeks.
- The second workout was the single biggest jump: 42% of the two-workout group kept going. Once the second workout happened, it made little difference whether it came 1-3 or 4-7 days after the first (67% and 65% active in weeks 9-12).
- Four or five workouts lifted the share still training to 55%, six or more to 82%. Combined, 74% of those with at least four workouts were active in weeks 9-12, against 24% of those with 1-3.
Why aim for four and not six? Six workouts in two weeks is three a week, which suits experienced lifters. For someone starting out, two a week fits into an ordinary week and leaves room to grow. Four is also where a second line appears: 42% of the four-or-five group still trained in at least three of the four weeks 9-12, against only 16-19% of the two- and three-workout groups. Regular training clearly separated from occasional visits only at four workouts.
Not just selection: the gap holds at every experience level
The obvious objection: experienced lifters do more workouts from day one and would keep going anyway, so the number only shows who already had the habit. So we split users by the experience level they chose in the onboarding chat. The gap held at every level, including beginners:
Active in weeks 9-12 by experience level
| Experience level | 1-3 workouts in 14 days | 4+ workouts in 14 days |
|---|---|---|
| Beginner | 21% (n 14) | 80% (n 10) |
| Intermediate | 26% (n 34) | 66% (n 53) |
| Advanced | 14% (n 22) | 84% (n 38) |
| Expert | 33% (n 15) | 73% (n 22) |
The beginner groups are small (14 and 10 users), so do not read too much into the exact percentages. The direction is the same at all four levels. This does not prove that four workouts cause people to continue: a less hectic life or strong motivation could explain both the early workouts and the staying power. But the number of workouts in your first two weeks is a useful warning light. If it stops at three, you are at risk whatever your experience.
One missed week will not break you, two in a row usually does
Everyone gets a week when a cold, a work trip or a sick child wipes out training. We looked at what happened when the first empty week landed in weeks 2-6:
First empty week in weeks 2-6 and staying power (n = 208)
| Weeks 2-6 | Users | Active in weeks 9-12 | Trained in 3+ of 4 weeks (weeks 9-12) |
|---|---|---|---|
| No empty weeks | 75 | 92% | 75% |
| One empty week, back the week after | 24 | 79% | 54% |
| Two or more empty weeks in a row | 109 | 21% | 9% |
The largest group, two or more empty weeks in a row, also includes people who quit right after the first week. So we looked separately at users whose first empty week came only in weeks 3-6, when the start was already behind them. Of those who came back after a one-week gap, 90% (19 users) were active in weeks 9-12. Of those away for two weeks or longer, only 34% (38 users). The rule is simple: a missed week is not a failure, but the week after it is the one you should not skip.
Overambitious plans fail more often
In the onboarding chat everyone picks how many times a week they plan to train. Those who picked three or fewer kept going more often than those who picked four or more: 58% and 46% were active in weeks 9-12. The gap also showed within the same experience level:
Active in weeks 9-12 by planned weekly frequency
| Experience level | Planned 1-3 times a week | Planned 4+ times a week |
|---|---|---|
| Intermediate | 58% (n 50) | 42% (n 36) |
| Advanced | 68% (n 37) | 41% (n 22) |
| Expert | 60% (n 20) | 53% (n 17) |
Only three beginners planned four or more sessions a week, so they are not in the table. Interestingly, those who planned four a week did barely more workouts in their first two weeks than those who planned three (5.0 and 4.9 on average). They simply fell further behind their own target. When the first two weeks delivered less than half of the plan, 17% were training in weeks 9-12. When at least half of the plan happened, 68-76% were. A target you can hit beats one you fall short of every week. Note: planned frequency is the user's current setting, and some may have changed it after starting.
Monday is the most popular day to start
A New Year's resolution is an example of what researchers call the fresh start effect. Dai, Milkman and Riis (2014, Management Science) found that the probability of visiting a university gym rose by 33% at the start of a new week, 14% at the start of a new month and 12% at the start of a new year compared with an ordinary day. SisuLift's data shows the same thing at the weekly level: 28% started on a Monday, followed by Wednesday (16%) and Tuesday (14%). Saturday was the least common starting day (7%).
The starting day did not predict who kept going in any consistent way: the groups were small (14-59 users) and the differences bounced around without a clear pattern. Neither did the time of day: 48-56% of morning, afternoon and evening starters were active in weeks 9-12. A fresh start helps you begin, but the next two weeks matter more than the day you pick.
What research says about forming a habit
In the study by Lally and colleagues (2010, European Journal of Social Psychology), volunteers chose one daily eating, drinking or activity behaviour and repeated it in the same situation for 12 weeks. On average the behaviour became automatic in about 66 days, but the range was 18-254 days. The key finding for a January lifter: missing a single occasion barely slowed the habit down. SisuLift's data shows the same pattern at the level of weeks.
Kaushal and Rhodes (2015, Journal of Behavioral Medicine) followed 111 new gym members for 12 weeks. An exercise habit formed in those who exercised at least four times a week for six weeks. A session did not have to be a gym workout, so in practice two gym sessions plus two brisk walks or bike rides a week meet the same bar. Consistency, keeping exercise simple and enjoying it also predicted the habit.
The meta-analysis by Gollwitzer and Sheeran (2006) pooled 94 independent tests of if-then plans, such as “when it is 5 pm on Monday, I go straight from work to the gym”. They improved goal attainment with a medium to large effect (d = 0.65). A bare intention like “I will start going to the gym” is not enough, because daily life beats it. Once the day, time and place are decided in advance, you do not have to make the decision again every time.
And making the resolution is worth it. In the follow-up by Norcross and colleagues (2002), 46% of people who made a New Year's resolution had been continuously successful after six months, against 4% of those who wanted to change but made no resolution. The Finnish gym chain Liikku reported that 70% of members who joined in January 2025 were still training in June (STT, 6 January 2026). Liikku's figure is based on gym visits and SisuLift's on logged workouts, so they cannot be compared directly. The message is the same: a January resolution is not doomed, it needs the right start.
A plan for January: how to keep your New Year's resolution
The research and the data point the same way. Here is a plan built around the first two weeks:
- Set the times before your first workout. Put two fixed slots a week in your calendar, for example Monday and Thursday at 5 pm. Decide the backup at the same time: if Thursday runs late at work, the workout moves to Friday morning, not to next week.
- Aim for 4 workouts in 14 days. Two full-body sessions a week are enough when you start, and the WHO recommendation for muscle-strengthening is exactly that: at least two days a week. Add a third session once two a week has held for about two months. Walking or cycling adds more movement, which gets you to four sessions a week like in the Kaushal and Rhodes study.
- Start with light weights. The job of the first weeks is to learn the lifts and come back next time. Pick a weight that leaves 2-3 reps in reserve and add to it gradually. Starting too heavy brings serious muscle soreness, and three days of stiffness is a bad way to begin week two.
- Do your second workout in the same week. In the data it was the single biggest turning point, and it made little difference whether it came three or seven days after the first.
- When you miss a week, protect the next one. Do not try to make up for it with a double session. Do one workout the following week, even a shorter one. One empty week is normal, two in a row is where most people stopped.
- Prepare for mid-January. Strava has used its activity data to name a mid-January day Quitter's Day, when the most New Year's fitness resolutions fade. In 2020 it fell on 19 January. If you start at the beginning of January, your second and third weeks land right there, so decide in advance what you will do in the week your motivation dips.
A ready two-sessions-a-week plan is in the beginner gym program, and the structure of the first months is explained in the beginner workout program guide. If you are wondering when to add a third or fourth session, read how often to go to the gym. Log every workout: a workout log shows when your weights go up, and progressive overload explains why they should rise little by little.
If you have heart or vascular disease, chest pain or dizziness during exertion, are pregnant or returning after giving birth, or take medication that affects your heart rate or blood pressure, talk to your doctor before you start. If your resolution is about weight and you have a history of eating disorders, make it a training goal rather than a weight goal and get support from a professional.
A resolution that sticks: make the goal something you do
In the experiment by Oscarsson and colleagues (2020, PLOS ONE), 1,066 people made a New Year's resolution and after a year 55% felt they had succeeded. Approach goals (“I will start doing”) succeeded more often than avoidance goals (“I will stop”): 59% and 47%. The same goes for the gym. The outcome is not under your control week by week, the doing is. Compare:
- “I will lose 10 kilos” → “I will do 4 workouts in 14 days and then 2 workouts every week.”
- “I will stop lying on the sofa” → “I go to the gym on Mondays and Thursdays at 5 pm.”
- “I will get in shape for summer” → “I will not skip two weeks in a row.”
A good resolution is small enough to keep even in a bad week and precise enough that you know straight away whether you kept it. The kilos, strength and summer shape follow if the doing holds. Once two sessions a week have held for two months, the research suggests the habit is well under way and you can upgrade the resolution.
How SisuLift helps you through the first two weeks
SisuLift is built for exactly this stage. In the onboarding chat you tell it your experience level and how many times a week you train, and the app builds a program where a beginner gets fewer exercises and sets than an experienced lifter. Weights go up automatically based on your logged sets, so you never have to guess the next workout's weight. Once your training days are fixed, the phone app reminds you on the morning of a training day which workout is up, and you can pick the reminder time under Profile → Notifications. If you get sick or go on holiday, Profile → Training break pauses the reminders, break days do not count as missed and your comeback workouts get lighter automatically.
Honestly about the limits: the free plan includes workout logging, automatic progression and reminders, and your program can have two active training days. That covers the starter plan in this article. The 14-day trial unlocks every Premium feature with no payment card, and the trial clock only starts with your first workout or food log (at the latest 30 days after signup). Start with a workout and the trial covers exactly the two weeks that decide it.
Sources
- Lally P, van Jaarsveld CHM, Potts HWW & Wardle J (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology 40(6):998-1009.
- Kaushal N & Rhodes RE (2015). Exercise habit formation in new gym members: a longitudinal study. Journal of Behavioral Medicine 38(4):652-663.
- Gollwitzer PM & Sheeran P (2006). Implementation intentions and goal achievement: a meta-analysis of effects and processes. Advances in Experimental Social Psychology 38:69-119.
- Dai H, Milkman KL & Riis J (2014). The fresh start effect: temporal landmarks motivate aspirational behavior. Management Science 60(10):2563-2582.
- Oscarsson M, Carlbring P, Andersson G & Rozental A (2020). A large-scale experiment on New Year's resolutions: approach-oriented goals are more successful than avoidance-oriented goals. PLOS ONE 15(12):e0234097.
- Norcross JC, Mrykalo MS & Blagys MD (2002). Auld lang syne: success predictors, change processes, and self-reported outcomes of New Year's resolvers and nonresolvers. Journal of Clinical Psychology 58(4):397-405.
- Bull FC et al. (2020). World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine 54(24):1451-1462.
- STT / MTV Uutiset (6 January 2026). Lopahtaako uudenvuoden liikuntalupaus heti alkuunsa? Asiantuntija kertoo, miten se muuttuu elämäntavaksi (in Finnish).
- Sports Insight (10 January 2020). Strava reveals 2020 Quitter's Day.
→ Read also: Beginner gym program | How often should you go to the gym? | Workout log guide