Learn Hardcore Norwegian: Hun trener minst tre ganger i uken, av og til fire. - She exercises at least three times a week, sometimes four.

In Norwegian, quantity-modifying adverbs usually come directly before the numeral: minst tre, omtrent fem, nesten ti. Saying tre ganger minst sounds odd. You can, however, move it to the end for afterthought emphasis if you add a pause/comma: Hun trener tre ganger i uken, minst.

Could I use i det minste instead of minst here?

No. Minst is the normal quantifier with numbers (minst tre = at least three). I det minste means at least in the sense of consolation/qualification (at any rate): Jeg kom i det minste tidsnok (I was at least on time). Don’t use i det minste directly with a numeral.

Why is there a comma before av og til fire?

The comma separates an afterthought/parenthetical addition. Av og til fire is elliptical (short for a fuller phrase) and is tacked on. A dash or parentheses would also work: … i uken – av og til fire. Without any separator, it reads awkwardly.

Why is ganger omitted the second time? Is av og til fire really okay?

Yes. Norwegian often drops repeated words when the meaning is clear. Here, av og til fire is understood as av og til fire [ganger i uken]. You can include it for clarity or emphasis: av og til fire ganger (and it still refers to per week because of the earlier i uken).

Why is it i uken (definite) and not i uke?

Frequency expressions take the singular definite:

en uke → uken/uka → tre ganger i uken/uka (three times a week)
Same pattern: i måneden, i året, om dagen. Using the indefinite (i uke) is ungrammatical in this meaning.

Is i uka also correct? What about i veka?

i uken and i uka are both standard Bokmål. I uken feels a bit more formal/written; i uka is very common in everyday speech.
i veka is Nynorsk.

Could I say per uke or hver uke instead of i uken? Do they mean the same?

per uke = per week; fine, a bit formal/technical.
hver uke = every week; different nuance.
- to ganger i uken means on average per week.
- to ganger hver uke emphasizes that it happens in each and every week.

Can I use other prepositions like om or på here?

Not for this meaning.

om en uke = in a week (future), not per week.
på en uke = within one week (time needed to complete something).
Stick with i for frequency: ganger i uken.

What’s the difference between av og til, noen ganger, innimellom, and iblant?

All can mean sometimes/occasionally, with small nuance differences:

av og til: neutral, very common.
noen ganger: neutral, perhaps slightly more literal (some times).
innimellom: colloquial, suggests sporadically/now and then in between.
iblant (also written iblant): a bit literary/less frequent.
All of them could replace av og til here: …, noen ganger fire.

Could I say Hun trener av og til fire without the earlier part?

No. Av og til fire only works as an ellipsis after you’ve established the unit (ganger i uken). Standing alone, Hun trener av og til is fine (she works out occasionally), but Hun trener av og til fire is incomplete.

Does the present tense trener here mean a habitual action?

Yes. Norwegian present tense commonly expresses habitual or general truths: Hun trener … = She works out (as a routine). You don’t need pleier å unless you want to emphasize usual tendency: Hun pleier å trene ….

Does trener also mean a coach/trainer as a noun? How do I tell?

Yes.

Verb: å trene (to work out/train), hun trener (she works out).
Noun: en trener (a coach).
Context and determiners reveal the role: treneren = the coach; hun trener = she trains/works out.

How do I pronounce tricky bits like av og til, ganger, and uken/uka?

Approximate, standard Eastern Norwegian:

av og til: [aːv o til]. In everyday speech, og is often just [o].
ganger: first syllable gang with ng as [ŋ] (like English sing), then -er as [ər].
uken: [ˈʉːkən] (long u like a rounded ee); uka: [ˈʉːkɑ].
Final r is typically tapped; some dialects weaken or drop it.

How do you count times correctly? Is it gang or ganger?

1 time: én gang
2+ times: to/tre/fire … ganger
This is the same gang/ganger used in multiplication: åtte ganger tre (8 × 3).

Could I rephrase the whole thing as a range, like tre–fire ganger i uken?

Yes. Alternatives:

Hun trener tre–fire ganger i uken.
Hun trener tre til fire ganger i uken.
Your original adds a nuance: at least three, occasionally four, rather than a flat range.

Is there any ambiguity with i uken meaning weekdays (Mon–Fri) rather than per week?

In this construction (tre ganger i uken), it’s understood as per week. I uka can mean “during the week” (as opposed to the weekend) in other contexts, but with X ganger i uken it’s the frequency reading.

Could I write the number as a digit (3) instead of a word (tre)?

Yes, especially in informal text or where many numbers appear: Hun trener minst 3 ganger i uken, av og til 4. Style guides often prefer words for small numbers in continuous prose, but Norwegian usage is flexible here.

Is there any difference between minst and alternatives like minimum or høyst?

minst = at least (lower bound).
minimum is a noun; you can say minimum tre ganger, but it sounds more formal/technical than minst tre ganger.
høyst/maksimalt = at most (upper bound), the opposite of minst.

Could I move minst to the very end?

Yes, as an emphatic afterthought with a pause: Hun trener tre ganger i uken, minst. Without a pause/comma, end-placing minst sounds off.