ðˈʌs wɛn ðə plˈeɪɚ hɐz dᵻplˈiːɾᵻd hɪz səplˈaɪ, ɪt kæn biː vˈɛɹi hˈɑːɹd ɔːɹ ˈiːvən ɪmpˈɑːsᵻbəl tə ɹᵻɡˈeɪn mˈoːɹ bˈuːsts.
Thus when the player has depleted his supply, it can be very hard or even impossible to regain more boosts.