Optimizing Slow SQL Query - mysql

Question

I have a query and it uses MySQL as its database. Now I'm going nuts as to why it took 11 minutes to render result, I have like 7K+ records on my table and running a recursive subquery(?), I'm not entirely sure if this is what eats up the memory but if you could look and give some remedy as to how can this be optimized I would be very happy and contented...
My goal is to compress records relative to a particular person... And rank them based on time finished.
Table structure:
CREATE TABLE `temptbl_raceeventresult_step1` (
`RunCatEventId` INT(11) NOT NULL,
`RunEventId` INT(11) NOT NULL,
`CategoryId` INT(11) NOT NULL,
`FullName` VARCHAR(255) NOT NULL,
`BIB` INT(11) NOT NULL,
`Category` DECIMAL(16,3) NOT NULL,
`Ord` INT(11) NOT NULL,
`TransitionId` INT(11) NOT NULL,
`Time` DATETIME NOT NULL)
COLLATE='latin1_swedish_ci'ENGINE=MyISAM;
//Query
SELECT
UCASE(g1.Name) Name
,g1.BIB
,g1.TimeDerived
,g1.CategoryName
,g1.TotalPace
,g1.Category
,COUNT(*) AS rank
FROM
(
SELECT
a.FullName Name,
a.RunCatEventId,
a.RunEventId,
a.CategoryId,
a.BIB,
a.Category,
a.Ord,
a.TransitionId,
SEC_TO_TIME(SUM(TIME_TO_SEC(Time) - (SELECT TIME_TO_SEC(Time) TimeMinuend FROM temptbl_raceeventresult_step1 WHERE BIB = a.bib AND (Ord + 1) = a.Ord AND CategoryId = a.CategoryId))) TimeDerived,
SEC_TO_TIME(SUM(TIME_TO_SEC(Time) - (SELECT TIME_TO_SEC(Time) TimeMinuend FROM temptbl_raceeventresult_step1 WHERE BIB = a.bib AND (Ord + 1) = a.Ord AND CategoryId = a.CategoryId)) / a.Category) TotalPace
FROM temptbl_raceeventresult_step1 a
JOIN (SELECT #cat:=null) xyz
GROUP BY a.RunCatEventId, a.RunEventId, a.CategoryId, a.FullName, a.BIB
) g1
JOIN
(
SELECT
a.FullName Name,
a.RunCatEventId,
a.RunEventId,
a.CategoryId,
a.BIB,
a.Category,
a.Ord,
a.TransitionId,
SEC_TO_TIME(SUM(TIME_TO_SEC(Time) - (SELECT TIME_TO_SEC(Time) TimeMinuend FROM temptbl_raceeventresult_step1 WHERE BIB = a.bib AND (Ord + 1) = a.Ord AND CategoryId = a.CategoryId))) TimeDerived,
SEC_TO_TIME(SUM(TIME_TO_SEC(Time) - (SELECT TIME_TO_SEC(Time) TimeMinuend FROM temptbl_raceeventresult_step1 WHERE BIB = a.bib AND (Ord + 1) = a.Ord AND CategoryId = a.CategoryId)) / a.Category) TotalPace
FROM temptbl_raceeventresult_step1 a
JOIN (SELECT #cat:=null) xyz
GROUP BY a.RunCatEventId, a.RunEventId, a.CategoryId, a.FullName, a.BIB
) g2
ON (g2.TimeDerived, g2.bib) <= (g1.TimeDerived, g1.bib) AND g1.Category = g2.Category
WHERE g2.Category = 5 AND g1.RunEventId = 3
GROUP BY g1.Name
,g1.BIB
,g1.TimeDerived
,g1.CategoryName
,g1.TotalPace
,g1.Category
ORDER BY g1.Category, rank