Learn French: Vous améliorez votre performance à condition de vous entraîner régulièrement. - You improve your performance on the condition of training regularly.

We use à condition de followed by an infinitive (vous entraîner) because the subject of both actions is the same (vous). If the subjects were different, for example if you were saying 'You improve on the condition that he trains', you would use à condition que followed by the subjunctive.

Why is it vous entraîner and not s'entraîner if the verb is in the infinitive?

Even when a reflexive verb like s'entraîner is in its infinitive form, the reflexive pronoun must still agree with the person performing the action. Since the implied subject doing the training is vous, the pronoun changes to match, giving us vous entraîner.

Why does the adverb régulièrement come after the infinitive instead of before it?

While short adverbs like bien or mal often go before an infinitive, long adverbs and those ending in -ment (like régulièrement) typically follow the infinitive they modify.

Is performance a false friend in French?