I need a towel.
Stress 'a-sciu-ga-MA-no'. The 'sci' makes a 'sh' sound.
Use this if you forgot your towel and the gym provides rental towels, or if you need to purchase one at the front desk.
'Ho bisogno di' means 'I need' (literally 'I have need of'). It is always followed by 'di' + noun. This construction is essential for expressing needs in Italian: 'Ho bisogno di acqua' (I need water), 'Ho bisogno di aiuto' (I need help).
Vendete asciugamani?
Do you sell towels?
If you want to buy one.
Posso noleggiare un asciugamano?
Can I rent a towel?
If the gym rents them out.
Ho dimenticato l'asciugamano.
I forgot my towel.
Explaining the situation.
Italian gym rules almost universally require a towel on all machines and benches. Signs reading 'È obbligatorio l'uso dell'asciugamano' (Use of a towel is mandatory) are standard. Some gyms provide small disposable paper mats as an alternative.