FORM OF OPTION GRANT AGREEMENT

Exhibit 10.23a

FORM OF OPTION GRANT AGREEMENT

THIS OPTION GRANT AGREEMENT, made as of the      day of              , 2006 between UNDER ARMOUR, INC. (the “ Company ”) and                      (the “ Grantee ”).

WHEREAS, the Company has adopted and maintains the 2005 Omnibus Long-Term Incentive Plan (the “Plan”), attached hereto as Attachment A, to promote the interests of the Company and its stockholders by providing key employees and others with an appropriate incentive to encourage them to continue in the employ or service of the Company and to improve the growth and profitability of the Company;

WHEREAS, the Plan provides for the Grant to Grantees of Options to purchase Stock of the Company;

NOW, THEREFORE, in consideration of the premises and the mutual covenants hereinafter set forth, the parties hereto hereby agree as follows:

1. Grant of Options . Pursuant to, and subject to, the terms and conditions set forth herein and in the Plan, the Company hereby grants to the Grantee a non-qualified stock option (the “ Option ”) with respect to          shares of Stock of the Company.

2. Grant Date . The Grant Date of the Option hereby granted is                      , 2006.

3. Incorporation of Plan . All terms, conditions and restrictions of the Plan are incorporated herein and made part hereof as if stated herein. If there is any conflict between the terms and conditions of the Plan and this Option Grant Agreement, the terms and conditions of this Option Grant Agreement, as interpreted by the Committee in its sole discretion, shall govern, unless explicitly provided to the contrary in the Plan or this Option Grant Agreement. Unless otherwise indicated herein, all capitalized terms used herein shall have the meaning given to such terms in the Plan.

4. Option Price . The exercise price per share of Stock underlying the Option granted hereby is $          .

5. Vesting . Except as provided in Section 9 and unless the Option has earlier terminated pursuant to this Agreement, the Option shall become exercisable as follows: 20% of the shares of Stock underlying the Option shall become exercisable on each of the first five anniversaries of the Grant Date, provided the Grantee remains employed by the Company on each such anniversary.

6. Term . Unless the Option has earlier terminated pursuant to the provisions of this Option Grant Agreement or the Plan, all unexercised portions of the Option shall terminate, and all rights to purchase shares of stock thereunder shall cease, upon the expiration of ten years from the Grant Date.

7. Employment Confidentiality Agreement. As a condition to the grant of the Option, Grantee shall have executed and become a party to the Employee Confidentiality, Non-Competition and Non-Solicitation Agreement by and between Grantee and the Company (the “Confidentiality, Non-Compete and Non-Solicitation Agreement”) attached hereto as Attachment B.

8. Forfeiture. If Grantee should take any actions in violation of the Confidentiality, Non-Competition and Non-Solicitation Agreement, or in violation of any non-competition agreement entered into between the Grantee and the Company, it will be considered grounds for termination for Cause as defined in Section 9(a) of this Agreement, and all unexercised portions of the Option, whether vested or not, will terminate, be forfeited and will lapse, as provided in Section 9(a).

9. Termination of Service.

(a) Termination of Service for Cause. Unless the Option has earlier terminated pursuant to the provisions of this Option Grant Agreement or the Plan, all unexercised portions of the Option, whether vested or unvested, will terminate and be forfeited upon a termination of the Grantee’s Service for Cause. For purposes of this Option Grant Agreement only, “Cause” shall be defined as any of the following: